Introduction of a yeast with rum aptitude in fermentation of sugar cane derivatives

Vidal F., Parfait A., 1994. Introduction d’une levure à aptitude rhumière en fermentation de dérivés de la canne à sucre. BIOS Boissons 249, 21–26. [My translation]

Introduction of a yeast with rum aptitude in fermentation of sugar cane derivatives
by
F. VIDAL* et A. PARFAIT**
* Centre Régional d’Innovation et de Transfert de Technologie-Biotechnologie et Agro-industries de la Caraïbe, BP n° 52, 971.52 Pointre-a-Pitre, GUADELOUPE FWI.

Summary

Rum is the most consumed white alcohol in the world. Among the different types of rums, traditional rums are all produced in the French overseas departments. In the French West Indies, rum technology has changed little. In distilleries, the largest losses happen in the fermentation workshops. Since the opening of the European market, the protection of French rums is less important and competition is becoming worrying. The reduction of losses and the regularity of production should allow local manufacturers to remain competitive. In this context, better control of the operations in the fermentation plants has become necessary. In the INRA yeast collection, a 493 yeast, adapted to the medium based on sugar cane gives interesting results in industrial distilleries. With very precise implementation conditions using an active dry yeast seeding technique, alcohol productivity gains can be estimated at 30%, which will have a direct impact on the cost price of rum. The working conditions at the factory will also be improved.

The diffusion of yeast 493 with its seeding technique is now acquired for the production of molasses rums. In an agricultural distillery, the problem is more complex because it is necessary to take into account the interactions between yeast and bacterial activities.

Introduction

Rum is the third most consumed spirits in the world. With more than 500 million liters of pure alcohol a year, it occupies 11.4% of the market on a par with liqueurs but after whiskeys (28%) and brandies (14%). The first white spirit consumed, it is progressing steadily in a global manner and remains, on the commercial front, an issue for the large multinational companies of brandies (1).

In the French West Indies, rum fermentation has been traditional since the 17th century; different types of rums are produced according to the raw material used. Their technical itineraries are presented on the diagram no. 1 (2). As provided by French legislation, they all come from a fermentation and distillation of cane juice or molasses or syrup from the manufacture of cane sugar. From a regulatory standpoint, rums must also meet “impurity” or non-alcohol content (ENA) levels that are presented in Table 1.

Currently, on the market, rums of molasses occupy a predominant place and more particularly so-called light rums; they are rums refined by extractive distillation which gives them a very neutral taste. They are then used for blends.

Agricultural rums are produced exclusively in the French overseas departments and may be subject to special protection with the establishment of a controlled designation of origin. Even if traditional rums production seems marginal, they remain very popular on the French market for their aromatic character.

State of the rum technology in Guadeloupe

In Guadeloupe, the annual production of rum is about 8,000,000 liters of pure alcohol (IPA) for 12 distilleries, which represents a significant component in the profitability of the sugar cane sector. The capacity of industrial units varies from 70,000 to 700,000 IAP for industrial distilleries ((3), (4)).

Rum technology has evolved, but among the main manufacturing stages, fermentation is the one that is the least controlled and that generates the most significant losses.

The fermentations are either spontaneous or activated by a complementary seeding of baker’s yeasts. They are carried out in 48 hours on untreated musts containing 90 to 140 g/l of sugars and giving wines containing 4 to 6.5% volume ethanol. Only nitrogen addition and acidification of the medium are carried out.

Seeding fermentation tanks is carried out according to different techniques: the process by tank-mother (generation of leaven on medium more or less aerated with concentrations in sugars close to 80 g/l), the bottom of tank (addition fresh must on a volume of wine not sent for distillation, rich in yeasts) and the cutting from a tank in the active phase of fermentation.

Whatever these techniques, the conditions for the implementation of leaven are poorly controlled and fermentation controls during manufacture are, when they exist, difficult to interpret.

The introduction of yeasts from bakeries (Saccharomyces cerevisiae) recommended in 1969 by MEJANE has made it possible to limit fermentation accidents but the ethanol yields obtained in distilleries are still low. Expressed in liters of alcohol per kg of reducing sugars, they are 0.52 for molasses and 0.47 for cane juice, whereas the theoretical yield according to PASTEUR is 0.643 IAP / kg (5).

According to TOURLIÈRE (6), a well conducted alcoholic fermentation should lead to a yield at least equal to 0.60 IAP / kg and any distiller should be able to get closer to this practical yield. ALARD and DE MINIAC (7) obtained yields of 0.62 IAP / kg on beet molasses.

Alcohol losses are expensive for distillers because they have a direct impact on the cost of rums, which are very high in the West Indies compared to other producing countries.

In this context, the introduction of a yeast adapted to rum fermentation was raised. The objectives are multiple: increase control of fermentations, reduce ethanol losses, limit bacterial contamination and improve working conditions in the distillery.

Introduction of a yeast selected distillery

We used yeasts from the INRA collection that were all isolated in production sites before the systematic introduction of baker’s yeasts.

During the laboratory selection, a Saccharomyces cerevisiae listed 493 was most active during the initial fermentation phase of cane juice and molasses with an interesting ethanol yield. These results were confirmed when comparing this 493 yeast with other commercial yeasts, including baker’s yeast used in the distillery (8).

Properties of yeast 493

A methodology has been put in place to characterize the strain at the microbiological and biochemical level, to compare its fermentative performances with those of other yeasts, and then to define the conditions for industrial implementation in the form of active dry yeasts. The goal is to make the most of the fermentative potential and technological interests of this strain. The work was carried out at three stages: laboratory, pilot and industrial.

 

 

The company LALLEMAND has been associated with these operations in the context of the production of strain 493 active dry form and in the comparative study of this yeast with yeasts of various origins belonging to their colleciontion

At pilot scale on molasses medium, experimental conditions have been established with reference to industrial conditions (9). We first validated the first results obtained on the capacities of the strain 493. Presented in the table no. 2, they show that the strain 493 has interesting fermentative potentialities on these media. Compared to baker’s yeast, Yeast 493 gives a yield and an ethanol productivity which are respectively 6.5% and 18.2% higher. The alcohol yields expressed in IAP / kg of reducing sugars observed confirm that the experimental conditions are close to the industrial reality since we obtain a yield of 0.524 for the baker’s yeast (corresponding to the figure announced at the industrial level).

To confirm the strong performance of yeast 493, a new comparative study was set up at the laboratory stage. Yeasts from the LALLEMAND collection have been selected according to their properties, either to withstand high temperatures or to support high osmotic pressure media such as strain no. 46 isolated by DE MINIAC from the National Union of Alcohol Distillers (10).

The results in table no. 3 confirm the previous outside observations. Strain 493 with yeast no. 46 are the most adapted to these types of environments; they give the best fermentation results. As a result of fermentation, the population level of strain 493 is very high, suggesting that its establishment and maintenance will be facilitated at the industrial level.

From a biochemical and microbiological point of view, the yeast 493 is a Saccharomyces cerevisiae var cerevisiae killer vis-à-vis the strain S6 and neutral to the strain 522D (toxin K2). Its pH and its optimum temperature. The growth rates are 4.5 and 33°C, which corresponds to the average fermentation conditions in the distillery.

The fermentative behavior of yeast 493 has been more specifically studied according to the density and temperature parameters which represent industrial constraints.

In distillery, the vat room is rarely equipped with cooling systems and it is common to note temperature rises reaching 36 to 37°C at the end of the exponential phase of fermentation. This lack of temperature regulation also conditions the low values of the initial densities of musts (1070).

Table 3- Comparison of yeasts in molasses fermentation at the laboratory

Table 4- Comparison of the serological balance between two processes: mother vat / baker’s yeast; pre-fermentation tank / yeast 493

Yeast 493, for controlled fermentation temperatures at 30, 33 and 36°, retains good yields of alcohol (Figure 1). On the other hand, the ethanol productivities decrease by 18.5% when one goes from 33 to 36 ° C, because at this temperature, there is a slowing of the sugar consumption at the end of the fermentary phase (figure no. 2).

This yeast also produces, for musts with a concentration of sugars of 185 g/l (density 1102), wines grading up to 9.1% ethanol volume without modifying the yield of alcohol. Even if a drop in productivity of 20% is observed when passing sugar concentrations from 120 to 185 g/l (Figure 3), the operating time of the distillery would be significantly reduced (about 30%).

Due to its background, yeast 493 appears to possess a genetic ability to grow on sugarcane-based environments. By introducing this yeast, accepting both high temperatures and high osmotic pressures, the operating times of the plants could be reduced.

Yeast seeding technique

From an industrial point of view, the seeding technique is important both for the progress of the fermentation and for the quality of the rums.

In a molasses distillery, the most common seeding technique is the mother tank, which is used to generate a leaven. With this method, the amounts of yeast used in dry form are low; population levels and qualities of starters are not controlled as are the risks of contamination.

While considering the financial criterion, we recommended, after a series of pilot level trials on seeding techniques, a process that takes into account biological phenomena (yeast requirements, quality and quantity of leaven, implantation of strain, reduction of contamination) and working conditions in the distillery.

This process consists in replacing the mother vats with pre-fermentation vats which, when seeded at rates of 0.5 g/l with active dry yeasts, make it possible to obtain quickly a high level of high quality population. After fermentation (about 25% by volume), the progressive filling of the fresh must protects against excessive temperature rises which will directly affect the productivity of ethanol.

Figure 2-influence of temperature on density drop

Figure 3 – Influence of density on productivity and ethanol yield

Industrial tests

We conducted a week of trials in industrial distillery on the whole of the vat room which represents 24 fermentation tanks of 130 m³ each is the production of 190,000 IAP. Yeast 493 yeast / pre-fermentation tank gives very satisfactory results (Table 4). Alcohol yields (0.595 IAP / kg of fermentable sugars) have increased considerably. The average alcohol content of molasses wines of 6% ethanol volume (for a concentration of sugars of 100 g/l) is very reproducible with a coefficient of variation on the whole of the vat room of 2%. It can be estimated that between the gains obtained on the alcohol yield (14%) and on the occupation time of the vats (-17%), the total productivity gain of the plant will be greater than 30%.

Implantation and maintenance of strain 493, followed by pulsed-field electrophoresis chromosome migration technique (11), is greater than 90% at the end of fermentation with a 100% viability rate persisting during the first waiting phase before distillation.

From a qualitative point of view, the triangular tasting tests carried out with a jury of consumers show a homogeneity between the different batches of rums produced with the yeast 493. Compared to the rum produced with the baker’s yeast, it has a taste and a Balanced aroma with no bad taste.

Conclusion

The introduction of selected yeasts in rum fermentation is of interest only if it brings a reduction of the losses in the fermentation workshop and a better functionality of the factory. This is the case of the process that we recommend (use of pre-fermentation tank with seeding of yeast 493 in dry form activated) which gives good yields of alcohol and interesting gains in terms of productivity in industrial distillery which will have a direct impact on the cost price of rum. The organization of work in the fermentation workshop will be facilitated with the use of a single wort at a constant density and a rational adequacy between the preparation of the pre-fermentation tanks and the fermentation tanks. The risk of contamination is minimized by the lack of mixing of the tanks between them and the production should be regularized both quantitatively and qualitatively.

Even if the recommended process uses larger quantities of active dry yeasts than the conventional one, it can be estimated that, in the case of the distillery as an industrial support point and in its current operating conditions, the financial burden supplement should not exceed 10% of the profits obtained with the combined use of yeast 493 and the new seeding process.

Similar studies on cane juice are currently underway. A methodology on the seeding technique should be proposed to distillers respecting both the aromatic quality of agricultural rums and the reduction of ethanol losses. Here, the case is more complex because the fermentation results from an association of yeasts and bacteria responsible for the aroma so much sought after by informed consumers; this situation must be taken into account.

Thanks

We thank LALLEMAND SA, which gave us the benefit of its expertise in the introduction of selected yeasts in fermentative environments and which supported this work by taking charge of the development of industrial production technology in active dry form for yeast 493. Miss RAGINEL be thanked for her assistance in the comparative studies between yeast 493 and those in their collection.

Our thanks go to Prof. STREHAIANO and P. TAILLANDIER from ENSIGC’s Bioengineering Engineering Laboratory in Toulouse for their welcome and their technical and scientific supervision during the implementation verification studies of yeasts in industrial sites.

We thank Professor GOMA and his collaborators from the Department of Biochemical and Food Engineering of INSA Toulouse who have put the laboratory equipment at our disposal for some work.

We thank the distilleries of Guadeloupe who have made available their facilities for work on an industrial scale.

This work was funded in part by European support from the STRIDE Community Initiative Program.

Bibliographie

(1) (1993). — Le rhum : un marché potentiellement très concurrentiel. Revue de l’union patronale de la Guadeloupe, décembre, 12-16.

(2) PARFAIT A., SABIN G. (1975).– Les fermentations traditionnelles de mélasse et de jus de canne aux Antilles françaises. Ind. Alim., 92. 1,27-34.

(3) RANCE H. (1992). — Étude technico-économique de la filière rhum aux Antilles françaises. Rapport de stage CRITT-BAC Guadeloupe. IUT La Rochelle, 52 pages.

(4) (1993). — TER Guadeloupe, éditeur direction interrégionale INSEE Antilles Guyane.

(5) DESTRUHAUT C, FAHRASMANE L, PARFAIT A. (1986). — Technologie rhumière. Rapport de fin de convention INRA/Distillerie St James.

(6) TOURLIÈRE S. (1985). — L’éthanol de fermentation : ses possibilités, ses limites. Ind. Agric. Alim., 6, 749-753.

(7) ALARD G., DE MINIAC M. (1985). — Recyclage des vinasses ou de leurs condensats d’évaporation en fermentation alcoolique des produits sucriers lourds. Ind. Agric. Alim., 102,9,877-882.

(8) FAHRASMANE L. (1991). — Amélioration du rendement de la fermentation alcoolique sur milieu à base de canne à Sucre. 1° rencontre internationale en langue française sur la canne à sucre. Montpellier, France.

(9) VIDAL F, BONNEAU L., PARFAIT A. (1993). —Yeast and rum production: survey of some trials. Congress & Distilled beverage industry – Fermentation – Technology, 21-25 mai, Orlando, Etats-Unis.

(10) DE MINIAC M. (1987). — Sélection de souches de levures pour la fermentation alcoolique de milieux mélasses enrichis en nonsucre de vinasse. Ind. Agric, Alim, 5,425-439.

(11) BLONDIN B., VEZHINET F. (1988). — Identification de souches de levures œnologiques par leurs caryotypes obtenus en électrophorèse en champ pulsé. Rev. fr. oenol., 28,7-11.

Contribution to the bacteriology of manufacturing waters of Guadeloupe distilleries.

Ganou-Parfait B., Valadon M., Parfait A., 1991. Contribution à la bactériologie des eaux de fabrication de distilleries de la Guadeloupe. AFCAS : 1re Rencontre internationale en langue française sur la canne à sucre, 296–302.

Contribution to the bacteriology of manufacturing waters of Guadeloupe distilleries.
by
GANOU-PARFAIT B., VALLADON M., PARFAITA.
INRA, LAPRA, CRITT-BAC, Pointe à Pitre, Guadeloupe

Summary

Water resources have two main origins: rivers and groundwater. The inventory of the bacterial microflora is oriented towards the search for germs that may have consequences in manufacturing.

Several factors influence the quantitative and qualitative composition of the bacterial population: thermal processes, mineral content and the use of antiseptics. Results are provided for some industrial sites.

Keywords: distillery, rum, bacteria, water, mineralization, contamination, antiseptic.

The distilleries of the Guadeloupe archipelago are located in three islands: Basse-Terre, Grande-Terre and Marie-Galante. The last two are characterized by a dry climate and calcareous soil. The water table and small rivers constitute the own water resource. Basse-Terre is mountainous and humid; surface waters are more abundant.

Manufacturing waters are not treated, they bring with the raw materials, most of the germs of contamination. To protect fermentative media from bacterial growth and activity, acidification is caused by sulfuric acid and certain fluoride-based antiseptics are used.

The bacterial flora also participates in the formation of the aroma.

Materials and methods

Water samples are taken at the feed of the industrial site. The operation continued for two seasons, 1989 and 1990 for a period from February to May. The treatment scheme is that of Figure 1. The different groups of bacteria are isolated from selective media (Table I). The counts of certain anaerobic bacteria, including sulphate-reducing bacteria are made according to the most favorable number method with a 95% confidence coefficient (ALEXANDER, 1982) and for this purpose on three tubes by dilution.

Other bacteria are counted by the Sartorius membrane filter method. The water is diluted and filtered on a filtration ramp. The filtration membranes for counting cellulose nitrate have a porosity of 0.2 μ and are then applied to the agar medium agar plate. The incubation takes place at 30°C for aerobic germs and gaspak jar at 30°C for anaerobic germs.

The determination of the minerals of the water samples was carried out by HPLC; these are first filtered under vacuum to facilitate degassing. After dilution, the samples are clarified by passage over Sep-pak columns. The anions are separated by passing through a Mitsubishi SCA03 column at room temperature with potassium phthalate eluting at pH greater than 8. They are analyzed on the universal UV detector JASCO 875 uv. The cations are separated by passing through a Mitsubishi SCK 01 column at room temperature. The eluent for alkalis is nitric acid and for alkaline earths is tartaric acid supplemented with ethylene diamine. They are detected by a WESCAM 215 conductivity meter. Figure 2 shows examples of separation. The different ions are quantified and recorded thanks to the integrator SIC calculator: Chromato corder 12.

Results

From a bacteriological point of view, there are aerobic germs (lactic acid bacteria, corynebacteria, Bacillus) more present in cane juice-based media and thermophilic and anaerobic germs (clostridia, Bacillus, sulphate-reducing bacteria) more abundant in molasses media (Table II). Antiseptics are used in the distillery to limit the activity of bacteria. The most commonly used is sulfuric acid (41/100 hl); it makes it possible to lower the pH of the meal to 4.5, but increases the concentration of sulphate ions in the fermentation medium.

It is possible that the metabolism of sulfur in yeast and in bacteria (BSR) has consequences on the aromatic fraction of rum and the quality of vinasses, a source of pollution on the environment. Other antiseptics have been used in Guadeloupe.

Quite often, besides the necessity of adapting yeasts to these antiseptics, resistant bacteria develop.

Table III: The waters of the rivers. Variation of mineral contents.

Laboratory tests have shown that bacteria in fermentative fermentation media can grow in the presence of high concentrations of sodium fluoride (0.28 g/l), sodium acid, sodium chloride and ethanol. This indicates an adaptation of bacterial germs to sodic antiseptics, to ethanol (up to 8 °GL in general) We have studied the variation of the manufacturing water contents in ions sodium, calcium, magnesium, chloride, nitrate and sulfate and the variation of the corresponding bacterial flora (Tables III, IV, V and VI).

 

Table IV : Variation of the bacterial flora in the water.

Aerobic bacteria

Lowland
At the beginning of the febriermars campaign, their number is of the order of 7.10^6 bacteria / ml of water then it regresses and stabilizes until the end of the campaign at 6.10^3 bacteria / ml

High land
At the beginning of the campaign it was possible to detect 1.10^3 aerobes / ml of water. This number remains stable during the campaigns except in April when it increases slightly to 1.10^4 bacteria / ml

Marie-Galante
In March, we detected 1.10^3 aerobic bacteria in the river water. In April they are of the order of 15.10^4 on average. Storage in concrete tanks shows an increase in aerobic flora: 11.10^6 bacteria / ml of water in April

Anaerobic bacteria

Lowland
The rains of April seem to favor the number of anaerobic bacteria, generally stable during the campaign. The population goes from 1 to 6.10^3 to 1 to 5.10^5 bacteria / ml

High land:
The water contains few anaerobic bacteria at the beginning of the campaign: 1.10^2 bacteria / ml in 1989, 2.10^4 bacterias / ml in 1990. We detected periods of strongest contamination as in March 1989 (Easter): 2.10^4 bacteria. At the end of the 1990 campaign, the number of anaerobes reached 5.10^4 bacteria / ml

Marie-Galante
We observed an increase of the anaerobic flora in time during the campaigns, it went from 10^2 to 10^4 bacteria / ml of water. However, the number has increased in the deep steel tank as it has decreased in the reservoirs, very wide and shallow concrete ponds: 50 to 100 bacteria / ml

Spore-forming bacteria

Lowland
The number of sporulated bacteria declines from beginning to end of the season. It goes from 10^3 to 10^1 bacteria for anaerobes and 6.10^2 for aerobes

High land:

Their population decreases during the campaigns. The sporulated anaerobes remain few: 4 to 7.10^1 and are not found in the countryside. Spore-forming aerobes are rarer. We observe a maximum in April of the order of 10^1 bacteria / ml

Marie-Galante
Spore-forming anaerobic bacteria are rare in water. Their number is around 6 to 10 in the tanks. Aerobic spore-forming bacteria increased in April from 10 bacteria / ml to 1.10^6 bacteria / ml

Sulphate-reducing bacteria

Lowland
The first months of the industrial campaign made it possible to count 1 to 2.10^2 bacteria / ml. This number of bacteria evolves by regressing the following months until being canceled at the end of the campaign

High land
Bacteria are generally in small quantities except at periods of a kind of contamination (March 1989 for example): 10^1 to 2.10^3 bacteria / ml. At the end of the campaign, we do not detect any more.

Marie-Galante
Their population is generally non-existent except in April: 10.10 bacteria / ml. At this same time their number is, in the steel tank, 2.10^2 bacteria / ml

Depending on the geographical location and the type of water, we note quite large differences between the diluting waters of the distillery raw materials.

The groundwater of Grande-Terre and Marie-Galante are in contact with seawater at certain times of the year. This probably explains the high chloride, sodium and sulphate contents of these waters. Well water from Marie-Galante has larger amounts of sodium, calcium, magnesium, chloride and sulphate than well water from Grande-Terre. It contains in addition nitrate.

Table V: Variation in Mineral Content in Well Waters (There was no well on the lowlands.

Table VI: Variation of the bacterial flora of well water.

Surface water is less mineralized than well water. The reserve water of Grande-Terre is equivalent to the mineral of Basse-Terre; it is in fact from this that the irrigation water of Grande-Terre is conveyed.

The bacterial flora of Basse-Terre, Grande-Terre and Marie-Galante surface waters are similar; however, we note that Grande-Terre’s irrigation water is a little richer in anaerobic bacteria and sulphate-reducing bacteria. The river water of Marie-Galante sees its flora vary quantitatively when it is stored. Masonry ponds seem to favor an increase in bacterial flora especially if they are poorly maintained and deep.

The well waters of Marie-Galante are more contaminated than the well water of Grande-terre; only the population of sporulated bacteria appears more numerous in the water of Grande-Terre. All these results show that there is a certain relationship between the mineralization of manufacturing waters and their bacterial population. Well waters that contain high concentrations of minerals are more contaminated by bacteria than surface water. It is difficult to say that this or that ion is responsible for the variation of the population of this or that bacterial group for the moment. We have simply found, for example, that in the brackish waters of the groundwater there are groups of BSRs, one of which has a halophilic tendency and that in some waters the decrease in time of concentration of sulphate ions corresponds to an increase in the number of SSBs.

Bibliography

ALEXANDER. M., 1982. Most probable number method for microbial population. Methods of soil analysis part 2. Chemical and Microgiological poperties. Agronomy monograph n’ 9 (2nd édition), p. 815-820

ANON, 1985. Standards methods for the examination of water and wastewater 16th edu. Washington D.C. American Public Health Association.

Jonscher A. For the knowledge and evaluation of rum, Rumverschnitten and Kunstrum. 1914

Jonscher A. Zur Kenntnis und Beurteilung von Rum, Rumverschnitten und Kunstrum, Z. Öffentl. Chem. 20 (1914), p. 329-336, 345-349.
For the knowledge and evaluation of rum, Rumverschnitten and Kunstrum
[untranslated German]

This paper is no block buster and the translation is not my best, but we can cross it off the list. It will probably interest few so I’d skip to the conclusion where the work of Karl Micko is discussed. The end adds a little bit to the debates of where that peculiar aroma comes from in rum. Jonshcer likes Micko’s eight fraction technique but not some of the other ideas Micko had. Some cryptic citations are given that may point to more of Micko’s work. I did republish his English language papers, but it would be useful to see if the foreign language papers are different.

A big takeaway is that lots of organizations were interested in spirits analysis for various purposes like fraud detection. The importance of various congeners and their ratios was being investigated relative to organoleptic assessment. They were even starting to weight the importance of ester counts knowing that much of the number was just ethyl-acetate.

For the knowledge and evaluation of rum, Rumverschnitten and Kunstrum.
From Dr. A. Jonscher, Zittau.

In 1912, the author of this article at the 17th General Assembly of the Association of Independent Public Chemists of Germany in Dusseldorf was able to bring his experience of the brandy “Cognac” to the general knowledge; Experiences that are already significantly expanded today and cause them to follow suit as soon as possible.

On the other hand, a second brandy, and indeed the rum, with its descendants, received proper attention and analytical research, which may be described in detail later.

From the literature, the following will first have to be present with reference to the characteristic components of rum:

Eugen Sell (Arb. Kaiserl. Gesundh.-Amt 1891, B. 7, S. 210.) has shown by examination of Jamaika rum, Cuban, and Demerara rum that the volatile acids contained therein consist chiefly of acetic acid, which considerably retreats to the contents of formic acid, butyric acid, and capric acid, and about equally 1/13 amounts to. In the case of the esters, the acetic acid ethyl ester then occurs about 12 times as much as the formic, butyric and capric acid ethyl esters taken together, which by the way are approximately in the ratio of 5:2:3.

K. Windisch (Arb. Kaiserl. Gesundh.-Amt 1893, B. 8, S. 278.) examined Jamaica, Cuba and Habanna rum distillates, taken by official means at the place of extraction, in the same way as Sell and found that there are Jamaican, Cuban and Habanarum, which are neither free Formic acid still contain formic acid ethyl ester. However, all show a strong salient acetic acid and acetic acid ethyl ester content in addition to the already butyric acid- and capric acid amounts and their ethylene ester shares.

In any case, the more frequent presence of formic acid and formic acid esters suggested that in real rum, in addition to ethyl alcohol, some methyl alcohol was also present, from which formic acid, etc. were oxidized by oxidation. Esterification emerged. This question was solved by Trillat and Quantin (Journ. de Pharm. et de Chim. 1900, S. 505; Pharm. Centralh. 1903, S. 12. ), the latter by using particularly large amounts of rum that the rum is always naturally free of methyl alcohol, which fact has also been confirmed by HC Prinsen-Geerligs (Chem. Zeitung, 1908, S. 70, 79, 99.), who concludes that The formic acid, which is often present in rum, must have been produced directly from glucose, at least not related to any methyl group in the sugar cane.

Th. Von Fellenberg (Mitt. aus dem Gebiete der Lebensm.-Unters. u. Hygiene veröffentl. vom Schweiz. Gesundh- Amt 1910, B. 1, S. 352.) has dealt with the nature of the higher alcohols of rum and, on the basis of his examinations, has come to the conclusion that they consist essentially of n-butyl alcohol. Further investigations are missing completely. But one may well with the statement Fellenberg’s opinion that it concerns the rum. The ratio of the higher alcohols to each other may be similar to that on the other hand (Zeitschr. f. öffentl. Chemie 1912, S. 421.) for cognac.

As far as the numerical analytical investigation of the rum is concerned, the following works are to be cited in this direction, which at the same time may set forth the development of rum analysis.

A. Skala (Atti della R. Academia Medica di Roma 1890.) and A. Herzfeld (Zeitschr. Zuckerindustrie 1890, B. 40, S. 645.) restricted their determination of the total amount of volatile acidity and esters in their numerical investigations to the determination of alcohol, extract and mineral content. E. Sell went one step further and also determined the closer composition of the acid and ester quantities. K. Windisch also considered the fusel oil content in addition to the investigation of the mass of individual acid and ester constituents. However, since he worked in the latter respect according to the Röse method, which almost always gives erroneous results in rum according to more recent experience, his reports on the fusel oil content of Jamaica, Cuba and Habannarum have only development-historical value.

There it was to be regarded as a noteworthy advance, as E. Beckmann (Zeitschrift f. Unters. d. Nahrungs- u. Genussm. 1899, S. 708.) for the determination of the higher alcohols in rum, etc. stated an exact method according to which the fusel oil first salted out by added calcium chloride, shaking with carbon tetrachloride, esterified with nitrous acid, and finally the nitrogen thus bound was determined volumetrically.

The newly examined type of investigation and form of publication, however, possessed defects in many directions. On the one hand, it was not extensive enough, and then the results were always given according to the different alcoholic strengths, which of course lost most of the orientational value. Meanwhile, however, a change had already begun for the better. Although E. Mohler (Compt. rend. 1891, B. 112, S. 53; Chem.-Zeitg. 1891 Rep. S. 13.) published the results of his Jamaikarum study for the corresponding alcohol strength, he already extended his investigations to volatile acidity, esters, aldehyde, furfurol, and fusel oil. Later, Lusson (Monit. scientif. 1896, B. 10, S. 785; Vierteljahrsschr. Nahrungs- u. Genussm. 1897, B. 12, S. 264.) first used cognac as a groundbreaking form of calculation for all alcohol constituents of 100 cc. absolute alcohol also for rum products of all kinds full application, d. H. From then on, the values ​​for volatile acidity, esters, aldehyde, furfurol and higher alcohols were determined at each scientific rum test and calculated for 100 cc of absolute alcohol, with the determination of aldehyde, furfurol and fusel oil simplified by colorimetric methods.

Now, if the analytic experiences about the different products of the rum producing countries are to be brought to the table in the following and all for 100 cc of absolute alcohol, then the test results of Windisch have to be put off in any case.

These investigations by Windisch (Arb. Kais. Gesund-Amt 1893, B. 8, S. 278.) with samples of Jamaika, Cuba and Habannarum carried out, even by official mediation (at least by consular officials) at the place of extraction itself, may therefore seem to some as particularly valuable, which also in this direction should not be disputed. However, on the other hand, in the name of the specimens or their design, there have been such gross deficiencies, especially at the time of this sampling, that the test results of these specimens are rendered completely unusable for a summary table of the composition of rum by trade; These samples are undoubtedly not exports, but merely intermediate production patterns from various distilleries in Jamaica, Cuba, and Habana. This can be seen from the fact that the alcohol content of the samples fluctuates from 53½ to 95½ vol.%, Although that of the export is constantly around 75 vol.%. Further, the two Jamaika rums that were present were the opposite of each other. One is an unusually aromatic product with 2499.0 the other with only 93.1 ester number. In general, fluctuations in the Habannarum were not so great; after all, the composition of these samples can also be explained as conspicuous enough. Finally, the Cubarum also had products with acceptable ester numbers as well as such a particularly low-flavor character. Finally, there are still 2 products that have an alcohol content of 95½ vol.% At an ester number of only 6 and 9, so from the usual framework of rum composition out that it is certainly sugar cane molasses alcohol under any circumstances but Cuba rum can act.

The following overview tables bring the literary experiences first of all over the Jamaika rum, which is most widely traded in Germany; followed by Cuba- and Demerara rum. After this, the products of the French colonies Martinique, Gouadeloupe and Réunion arrive for illustration. The number of analyzes carried out by the individual researchers is enclosed in parentheses or otherwise identifiable.

(13) Zeitschr. Nahrungsm-Unters, Hyg. u. Warenk. 1895, B. 9, S. 317.
(14) Journ. Chem. Soc. Ind. 1907, B. 26, S. 496.

So far, the literature with its experiences, according to which our knowledge of rum are certainly not as insignificant.

Now, in 1891, E. Sell, following his rummaging work, liked to make the statement, cited in particular in relevant circles of commerce and on every occasion, that in the ruling on the ruling, the best choice would be given to such an expert taste and smell sample. “This sentence was allowed to claim validity at Sell’s time, but today it is completely without authorization. In Sell’s times (thus 23 years ago) the chemical rum knowledges, as well as the above explanations clearly enough show, so in the error, that of a correct chemical evaluation could not be the question, and the soon appearing work of Windisch with the mentioned officials had to just increase the uncertainty only. Today, on the other hand, our chemical knowledge in the area of ​​the rum areas is so extended and fortified that the experts are no longer those who can only smell and taste, but rather those who, in addition to a trained tasting, at the same time individually taste the odors and flavors themselves determine and prove. But that is only possible for the food chemists equipped with special exercises, as the preceding and following general reports teach on their own.

Echter Rum. [Real rum.]

When discussing the food chemistry assessment of true state-of-the-art rum, it must first be stressed that rum is a peculiar fermentation and distillation product, with both fermentation due to deviance in different countries as well as distillation depending on the design of the still and after the cutting process a number of differences conditionally, can never be absolutely equal. Thus, better and lesser products occur naturally, and on a fully natural basis, more often than in other foodstuffs. Therefore, the French chemists and the French trade in accordance with the approach of Bonis and Simon divide the real Rum sold there into three classes, which they according to the aroma d. H. delineate according to the amount of the Lusson Girard numbers in the Martinique rum, which is particularly popular in France, as follows:
Type supérieur 550–900
Type moyen 450–550
Type inférieur 350–450

The English chemist Williams, and with him the English trade, distinguishes only two qualities in the Jamaika rum, which is most in demand in England and Germany, which are also distinguished by the aroma and the Lusson-Girard numbers:
Ordinary Jamaika rum 300-550 Fine aroma.
Jamaika rum 550-1000

These natural differences in quality can not be avoided in the German trade, because they are also represented here, as 6 by the author in association with Dr. med. M. Groneberg examined real Jamaika rums from public transport:

The question of quality always has to be answered first in the case of rum with the analytical documents that have been determined, since it also plays an outstanding role in practical trade. The only question is whether the current type of evaluation with the Lusson Girard numbers can be recognized as completely flawless and strictly fair. But this can not be added for all cases, because
a) Furfurol has hardly any flavor value at all,
b) the acetic acid probably has a conditional taste value but no aroma value,
(d) the higher alcohols have only a slight flavor and flavor value, but become directly harmful in the case of greater prevalence and produce the unpleasant “Blasengeschmack” [alembic taste] according to Simon;
e) thus the esters and aldehydes alone may be considered as wholesome flavorings.

If this is the case, it is impossible to sum up the number of parts found according to Lusson-Girard, and then to sum up the sum definitively and determine the quality; for it will often happen that particularly pungent and acetic acid-rich rum products, which must almost be regarded as defective in taste and originate from a deficient distillation process, are valued particularly favorably, which is certainly not intended. At any rate, however, such errors are avoided if the number of pieces calculated according to Lusson-Girard are put together as follows:
1. Aldehyde and esters are used with the fully weighted Lusson Girard values; the same thing can be safely done with furfurol, since its low levels of presence are never able to make a difference;
2. Acetic acid and fusel oil, however, according to modern experience, which suggest a decrease and a purer distillation in the production areas, are brought to the summation at only 75; the plus or minus of the actual determination of these 2 bodies is then simply put to disposal in the closer appraisal.
3. For quality 1, the rum varieties are to be counted, which with the indicated valuation amount over 550, to quality 2, finally, those, which are below 550.

The 2 different Jamaika rum series analyzed by W. C. Williams receive here with their averages the following expression form:

This expression clearly shows that these are 2 different qualities, since the score is 944 in one case and 536 in the other; but it also continues to prove with the plus and minus additives that in both cases there are no defective distilled products, since the deviation from the modern normal content in acetic acid and fusel oil is only relatively small.

Rum verschnitt. [Rum blended.]

After these explanations on the quality question and the basis of evaluation of real rum may now also come to the assessment of the rum products, which were mixed with purified spirit. Again, with the Lusson-Girard payment, you are able to provide all the information you need, especially when (as in the case of whole milk samples) a control sample of the rum that is supposed to be used for the blend is used. As the rum blends now contain almost all more purified spirit than Jamaica rum, etc., it goes without saying that a closer knowledge of how this spirit generally behaves in the Lusson-Girard affirmations is very appropriate. For this reason, first of all, a work by Girard and Cuniasse (conf. X Rocques, Eaux de vie, Paris 1913, S. 179.) on 13 samples of French industrial spirit is presented in tabular form in the literature:

After this the German industrial spirit with 2 investigations of the author and Dr. med. M. Groneberg from 1914 to illustrate:

With this knowledge also important. In view of the nature of the purified industrial spirit, it will now be possible to approximate the respective content of real Jamaicarum slightly in the case of the rum blends in commerce, as will be shown by examples from this worldly practice.

For the more precise assessment of the content of real Jamaica rum, it is not necessary to use the analytically found Lusson girard values for the high-quality blends which (as in 4805 and 68) reveal themselves with a higher aldehyde content deduct from Lusson girard numbers, because these parts are of little importance in such blends; but in the case of low value cuts, which as such also characterize the aldehyde number, this withdrawal is essential and may include, without significant error, the full average value for purified industrial spirit. In this procedure one obtains in the 4 last Rumverschnitten above table, which are to be considered alone as low-grade in this sense, since they can expect only about 10 to ½% Jamaikarum, the following number of rumor indicating number of Lusson-Girard:

Since the average Lusson-Girard number for the Jamaicarumqualitaten 1 and 2 according to W. C. Williams 771.3 addition to an aldehyde and ester content of 18.0 bezw. 567.5, we now arrive at the Jamaikarum contents of the above 6 sample cuts on the following basis of calculation and calculation:

Sample 4805 shows a Lusson Girard number of 224.5 with an aldehyde and ester content of 9.3 and 171.6 respectively. The mutual relationship of these numbers is quite normal and leads to the equation: 771.3: 100 as 224.5: x equals 30% Jamaika rum.

Sample 68 shows a Lusson Girard number 254.2 at an aldehyde and ester content of 80 and 193.6 respectively. The mutual relationship of these numbers is again normal and leads to the equation: 771.3: 100 as 254.2: x equals 33% Jamaika rum.

Sample 138 shows a corrected Lusson-Girard number of 81.8 at an aldehyde and ester content of 3.0 and 44.0 respectively. The ratio of these numerical parts is again normal and leads to the equation: 771.3: 100 as 81.8: x equal to 10% Jamaika rum.

Sample H shows a corrected Lusson Girard number of 74.0 at an aldehyde and ester content of 1.5 and 60.9 respectively. The ester content is here in comparison with aldehyde, acid and higher alcohols and clearly shows that a particularly high-ester Jamaika rum was used for the blend, the ester content was certainly about 1/3 above the usual average mass.

For the correct calculation, the average Lusson girard number of the Jamaica rum of 771.3 must therefore either be 1/3 of its ester amount d. s. 189.2, or the Lusson Girard number of the test sample is reduced by 1/3 of its ester amount, which means the same. In the case of the latter form of calculation, the following equation then results: 771.3: 100 as 53.7: x equals 7% Jamaika rum. The manufacturer later admitted that only 5% Jamaica rum was used for Sample H.

The sample P. 36 shows no aldehyde content at all and can therefore contain only a negligible amount of real Jamaica rum. It was therefore declared to be deceptive in the sense of § 10 of the Food Law, whereupon the manufacturer submitted the sample P. 48, which was affected by the same destiny, since the aldehyde content with 0.1 allowed only an addition of 0.6% real Jamaika rums. Incidentally, the aldehyde and ester content was in striking disproportion, which suggested the use of an extraordinarily aromatic Jamaika rum.

The complaint continued by the manufacturer, who did not want to believe that it was possible to judge rum products so sharply, finally led to the taking of a control sample of the used genuine rum of the following composition:
Volatile acid 173.4
Ester 1530.3
Aldehyde 23.5

Thus, both the suppositions on the part of the Jamaika rum used in this case and the fact that the Rumverschnitt sample P. 48 could actually contain no more than 0.5% real Jamaika rum and was properly complained of under § 10 of the Food Act.

If one does not want to start from the absolute average of the Lusson-Girard numbers to Williams when assessing and calculating Jamaika rum products but distinguishing the conscious 2 quality series from the outset, one has the quality average values for the above-mentioned absolute average number of 771.3 and 545.8 respectively to insert 996.9. The result of the calculation then reflects the probable additional amount of Jamaika rum in the form of the Jamaica rumored qualities, which certainly has its amenity.

Kunstrum.

After these presentations about real rum and Rumverschnitte Kunstrum may now find a discussion that is often produced with the aid of Rum essence also using some real rum and in the retail trade only too often with the deceptive name “Rum” or “Rumverschnitt” appears.

In this direction, relatively little work is available

A. Skala (Atti della R. Academia medica di Roma 1890.) placed in a Kunstrum to 100 cc. absolute alcohol 258.0 milligrams of acetic acid ethyl ester in addition to 43.0 formic acid solid.

E. Mohler (Compt. rend. 1891, B. 112, S. 53; Chem. Zeitg. 1891, Rep. S. 13.) examined 1 sample Kunstrum with the following results:
Volatile acid 13.4
Ester 5.8
Aldehyde 5.8
Furfurol 0.5
Higher alcohols 18.0

Both products can easily be recognized as artificial with these numbers in mind, taking into account the present scientific rumor experience, without the event, artificial coloring or the nature of the flavor at tasting needs any support. This applies in particular to the Mohler sample, it should be noted that there is neither a real rum nor a Rumverschnitt, which could show on 5.8 aldehyde only 5.8 esters. But even the Skala sample is immediately recognized as Kunstrum, based on the experience of Sell (Arb. Kaiserl. Gesundh.-Amt 1891, B. 7, S. 210.), which found that in real rum to 26 milligrams of acetic acid ethyl ester barely 1 milligram of formic acid ethyl ester, while in the real sample three times the amount of formic acid is found. With extended investigation, this sample would certainly have betrayed in some other direction as Kunstrum. For example, the rapporteur examined 2 products as “rum” on the market, with the following result:

The sample 10 was immediately recognizable by the striking disproportion of aldehyde to esters as Kunstrum. Support in this direction then allowed the presence of tar dyes as well as the abnormal smell and taste. Sample 9 also showed an undeniable mismatch of aldehyde and esters, which was not so obvious. However, with the help of the abnormal smell and taste as well as the abundant presence of tar dyes, this product could certainly be identified as an artificial form. Perhaps the exact determination of the quantities of formic acid as acid and ethyl ester in this rum 9 would still have been possible, which direction has recently been described by H. Finke (Zeitschr., In the Untersdt., Essen, and Genussm., 1913, B. 25, p .), loading material is given to the hand. Unfortunately, this beautiful work by Finke in the attached tables (as well as that of K. Micko (Zeitschr., For sub-d .. Food and pleasure M 1908, B 16, p 438 and B. 19, p 307.) miss the clarity which is so urgently needed in the interest of our entire science, such as the specialized science of spirits, and in particular of rum, since in this field one can only get along with the most painstakingly compiled results of investigations and have a convincing effective wish that in the future all accurate work in the field just described should always give its results calculated on 100 cc. of absolute alcohol, which must be based in particular on the fact that the scientific basis is not limited to specialists in the fine brandy field Laypersons should be able to grasp who, in case of complaint, may claim for clarification then to identify the relationship of event ascertained formic acid and formic acid ester compared to the total volatile acid and total esters are approximately the following tabular form selected and completed:
Volatile acid     with formic acid:
Ester                   thereby antsester:
aldehyde
Furforol
Higher alcohols

Only with this uniform form of publication can one obtain an absolutely clear basis of assessment, by which science, and in particular food chemistry, is served alone.

In 1908 K. Micko, whose name has just been mentioned, drew attention to a completely different distinction between Kunstrum and Rum after discovering a characteristic rumor in the Jamaika rum through a fractional distillation process, namely in the 5th and 6th fractions, who, according to his experiments, counts among the essential oils. This work was followed in 1910 by another (Zeitschr. f. Unters. d. Nahrungs. u. Genussm. 1910, B. 19, S. 305.), for which this researcher 5 samples of real Jamaika rum of the company Segnitz & Co., Bremen, a sample conc. Jamaika rum of the “Jamaikarumcompany” in Amsterdam, as well as 3 samples of real Cubarum, as well as each 2 samples genuine Demerara rum and real Batavia Arrak on its typical Rum frangrance had examined, d. H. 11 samples of sugar cane and 2 samples of rice distillates. The result of the investigation was, in Micko’s own words, such that:

a) in the case of the 3 samples Cuba rum (according to p. 308, para. 4) “the fragrance of the 5th and 6th fractions was reminiscent of Jamaika rum, but did not stand out clearly”;
b) in the 2 samples Demerara rum (according to p. 309, para. 2) “in the 5th, 6th and 7th fractions a smell similar to the typical fragrance of the Jamaica rum but not distinctly pronounced”;
c) in the case of the six samples Jamaika rum (according to p. 310, par. 3) “in all samples the typical fragrance, as it primarily characterizes the Jamaica rum, could be very clearly detected”;
d) in the 2 samples Batavia-Arrak (according to p. 313, para. 7) “the smell of the typical fragrance of Jamaicarum was also clearly perceptible”.

Despite these clear results, Micko sticks to it:
1. “that its typical rum fragrance arose during the fermentation, because in the sugar cane certain bodies are contained, which supply during the fermentation that wonderful perfume”, and
2. that this fragrance was made to distinguish rum.

Unfortunately, both are wrong! For if the Micko’s Jamaika rum fragrance had originated by the sugar cane fermentation and passed over in the distillation, it would have to appear undiminished in all real rum products so also the Cuba- and Demerara rum, and should not on the other hand in rice distillates d. H. Batavia-arrak. However, its odoriferous substance undoubtedly has nothing to do with the actual production of rum by distillation, but rather depends either on a deviating treatment of the distillate in certain parts of the country or, finally, only on the last form of shaping. H. combined with the graining and dyeing, which is certainly treated as a factory secret and therefore also in the distilleries themselves in Jamaica may be different. This view is also imposed by the purely practical consideration that the rum comes to us in a strength of about 75 vol.% And must be distilled so high percent, in any case, if you do not also want to accept a backward dilution with water. Of course, under such distillation conditions, all the constituents of the sugarcane fermentation remain, which go so heavily that they are mixed with 30 cc of water during the test procedures of Micko (where 200 cc of Jamaica rum are mixed with alcohol up to 40% by volume) Subjected to distillation and collected in 8 individual fractions of 25 cc each) only in fractions 5 and 6 which are already excessively diluted.

That then such a fragrance, which originates from the substrate, which according to experience is also arbitrarily chosen in the case of cognac, can serve to distinguish between artifacts, may be admitted in many cases; As a rule, however, the variety of its products and the diversity of its products will lead to so many errors that it is even less possible to speak of an infallible distinction, since the survey of the art excludes not only the absence of Jamaica literature but of all literature must be achievable, as it can only be achieved with the most accurate chemical investigation in conjunction with a purposeful degustation.

K. Micko and, together with him, G. Kapeller and Schulze (Pharm. Centralballe 1910 B. 51, S. 165-170.), who have verified that rum process, are, after all, on a questionable judicial refusal, since they assume that a flavoring is the unmistakable main feature of the authenticity of a rum product. which is connected with the sowing and coloring of the rum and therefore as often deviant and as a whole is to be presented as incidental. At the same beginning in the cognac assessment I come back elsewhere.

Hopefully, these overall observations will help to make the old-fashioned, and with much effort created by the best food chemists, chemical appraisal bases in the Roman region a fairer tribute and appreciative acknowledgment. In combination with a practical degustation, they offer the opportunity to be able to correctly and sharply evaluate all kinds of rum products. There is really no need to resort to procedures which, since they do not go to the heart of the matter, become obsolete at all times and can never provide complete security at all.

Fincke E. About the distinction between Jamaikarum and Kunstrum. 1913

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Fincke E. Über die Unterscheidung von Jamaikarum und Kunstrum, Z. Unters. Nahr. Genussm. 25 (1913), p. 589-596.
About the distinction between Jamaikarum and Kunstrum
[link to the original German]

This paper is no block buster but it does give a glimpse of scientific advancement in tackling first the puzzle of fraud and then eventually using the same tools for advancement in the distillery. Some of the techniques in here would become quickly outdated such as measuring free volatile acidity as formic instead of acetic. Eventually around the work, techniques of analysis would refereed and collectively improved. Personally, I’m trying to locate the origins of a few of the techniques I want to champion. So far it looks like Karl Micko invented them before they were perfected by Arroyo. Keep in mind the rums in here are original rum which is a concentrate. Then a stretched version of that which is diluted with local German spirits then adulterated rum and a version of adulterated rum that has a percentage of original rum.

About the distinction between Jamaikarum and Kunstrum.
(Fifth communication of contributions on the determination of formic acid in foodstuffs.)
From
Heinrich Fincke.
Communication from the Food Inspectorate of the City of Cologne
(Director: Dr. Große-Bohle.)
(Received on 14, March 1913.)

That rum contains free formic acid and formic acid esters is known, as well as that the artificial rum essences contain formic acid esters. It seemed doubtful to me that the formic acid content of rum on the one hand and Kunstrum on the other hand fluctuated within the same values. I therefore made determinations of free and ester-bound formic acid in a number of samples of rum, rum blends, Kunstrum, and rumessenz. In order to exclude disturbances of the formic acid determination by aldehydes and other non-acidic components, steam distillation by calcium carbonate alluvium was used. Further, sodium chloride was added to the solution to be heated with mercuric chloride, as in this way, as already reported (Diese Zeitschrift 1913, 25, 386), a purer mercuric chloride is obtained. The investigation showed that the formic acid determination in many cases with success to the distinction of Rum bezw. Rumverschnitt and Kunstrum can be used. In the context of other results of the study, this will be reported below.

The study covered the content of fragrance, tar dye, alcohol, esters, free and ester formic acid.

The volatile acid was also initially determined in a part of the samples according to the suggestion of Micko (Diese Zeitschrift 1908, 16, 437.). However, it has been shown that the method not only gives no real but also no comparable values, since the amount of volatile acid passing in a certain amount of distillate is also dependent on the alcohol content by high alcohol content (i.e. original rum samples) passes relatively less acid as in low-alcohol blends. For a reasonably correct determination of the volatile acidity in rum, it will be necessary to do the same with wine. Attempts were not made.

The test for perfume was done by Micko (Diese Zeitschrift 1908, 16, 440 und 1910, 19, 310). The odor test of the individual fractions obtained in the distillation proved to be a valuable means of rum judgment. In order to obtain the fragrances always approximately in the same fraction, it seems to me appropriate to dilute samples with higher alcohol content by means of water up to about 30 Vol. % alcohol.

For the determination of the alcohol, 25 cc of the sample were diluted with 35 cc of water and subjected to distillation; In a 50 cc pycnometer about 45 cc distillate was collected and treated in a known manner on.

The determination of the ester content was combined with the determination of formic acid. For this I proceeded as follows: 100 cc of original and artificial stone were mixed with 1 g of sodium acetate in 200 cc of the sample in a flask of about 600 cc in diameter, fitted with a double-perforated stopper, steam inlet tube and distillation head and connected to a steam generator. This additive was intended to prevent as far as possible the transition of free formic acid during distilling off the esters. The distillation head was connected to a Liebig’s condenser of at least 50 cm shell length. Passing a slight stream of steam, 125 cc were distilled off-when 200 cc of the sample had been applied-200 cc distilled off. The heating of the flask was conducted so that the volume of liquid was reduced to about 50 cc.

The distillate was initially set aside for the determination of esters and ester formic acid.

Between the distillation head and Liebig’s condenser, a long-necked flask equipped with Stoltzenberg’s steam inlet tube was then connected, which was charged with a precoat of 2 g of calcium carbonate in about 100 cc of water. The liquid in the first flask was acidified by the addition of 2 g of tartaric acid. With vigorous steam flow I produced 750 cc of distillate and kept the liquid volume in the flask evenly to 50 cc. The filtrate of the calcium carbonate alluvium was acidified with a few drops of dilute hydrochloric acid and heated in the usual way with sodium acetate, sodium chloride and mercuric chloride. The value determined from the weighed mercury chloride indicates the amount of free formic acid.

The first distillate containing the esters was neutralized and allowed to stand with a measured excess amount of 1/10 or 1/4 N sodium hydroxide solution for 24 hours at ordinary temperature. Back titration gave me the amount of alkali used to saponify the esters. If back titration showed that only a slight excess of alkali was present, that is, that the amount of alkali used had possibly been insufficient, a measured amount of liquor was again added and the residue was titrated back after a further 24 hours.

The resulting neutral liquid was concentrated in the water bath to about 30 to 40 cc and subjected to addition of excess phosphoric acid in the same apparatus and in the same manner as in the determination of the free formic acid of the steam distillation by a calcium carbonate alluvium. The filtrate of the latter was also treated as indicated there. The value obtained indicates the content of ester-formic acid.

The results are set forth in Table p. 594 and 595. In addition to the aforementioned provisions, a number of calculated values are listed here.

In order to be able to conveniently compare the values for esters, free and bound formic acid with each other and with other values, their amounts are stated, except in the amount by weight, in tenths of milligram equivalents = cc of 1/10 N. lye.

The sum of free and ester formic acid is calculated as total formic acid.

The tenths of milligram equivalent values for ester, free, ester, and total formic acid have been calculated to be 100 g of alcohol, since this eliminates the influence of the variability of alcohol.

It is also determined how many parts of ester formic acid and total formic acid (in equivalents) are present per 100 equivalents of total ester.

Endlich ist dieses Verhältnis der Gesamt-Ameisensäure zur Estermenge berechnet worden, nachdem von der in 100 ccm der Probe enthaltenen Gesamt-Ameisensäure 0.5 1/10-mg-Äquivalent (= etwa 2 mg Ameisensäure) in Abzug gebracht sind. Der Grund dieser Berechnung wird im nachfolgenden erklärt werden.

In a rum sample that is not unchanged orginalrum, there are the following options:

1. Original rum is adjusted to drinking strength by adding water. Here, the alcohol content and all other values are evenly reduced, but their quantitative ratio remains unchanged. The strength of the dilution results from the alcohol content.

2. Original rum is stretched with alcohol of the same strength. In this case, the alcohol content remains unchanged, however, the alcohol-related values of the other ingredients are depressed. The strength of the elongation results from the values calculated for alcohol for ester and free and ester-shaped. Formic acid.

3. Original rum is stretched with water and alcohol at the same time This case is in the production of ready to drink Rumverschnittes ago. Both the values for alkohol and all other constituents are reduced, but to varying degrees. The dilution with water results from the alcohol content, the dilution with alcohol from the values calculated for 100 g alcohol for ester and formic acid.

4. The product has received an addition of artificial rum essence. There may have been an addition of rum or have been omitted. If rum has been used, then at the same time a strong stretching with water and alcohol took place, otherwise the addition of ester would be pointless. Depending on how rum is used or not, and depending on the composition of the rum essence, very different values will be obtained.

With the specified provisions, one will generally come to a safe judgment even in these cases. If there is no typical Rum aroma, so Kunstrum is of course. If rum aroma is detected, the amount of ester must be reasonably consistent with the strength of the perfume; high ester value with low perfume content indicates the addition of artificial esters.

The Rum aroma is still in strong dilution, usually even in a dilution of the original Jamaican rum 1: 100 perceptible. The Rumverschnitte usual in the trade contain at present usually not (at least not substantially) over 5 to 7% of original Rum. The ester content of a Rumverschnittes is accordingly low. Since the alcoholic strength of the original rum is about twice that of the rum blended, the percentage of alcohol originating from the original rum is greater by the same amount.

If there are doubts as to whether the perfume content of a rum sample is sufficient in comparison to the ester content, dilute the sample with 30% alcohol to such an extent that the amount of ester contained in 100 cc is equal to about 1 cc 1/10 N. lye. According to my experience so far, the fragrance in the fractional distillation is still clearly perceptible.

If the composition of the artificial rum esters deviates from that of the natural rum esters, as is usually the case, this must be expressed in the results of the investigation. To determine a difference in the composition of the esters is primarily the formic acid determination, because the formic acid can be determined even in small quantities with reasonable accuracy, and because it is an integral part of the Rum aromas. Also, the formic acid content of the artificial rum essences is usually considerably larger than that of the natural Rum ester, if it refers to the total amount of ester in both cases.

Here, however, a difficulty must be considered. When investigating rum samples that were reliable and that were otherwise perfect in the test results, slightly larger amounts of free formic acid were found than expected from the study of the related original rum samples. In one case about 0.35 mg was expected, in the other case 0.65 mg of free formic acid in 100 cc; instead, 1.71 mg, found 1.03 mg, respectively. The increase may be due, at least in part, to unavoidable decomposition of the sugar in the distillation, but the surplus value obtained in the first case was too high to make this assumption appear sufficient. The explanation was found in that the formic acid found was partly derived from caramel, which was used for dyeing and usually contains small amounts of formic acid. In several caramel solutions, so-called Zuckercouleur, which were subsequently examined, the following amounts of formic acid were found in 100 cc: 1st trace, 2. 0.058%, 3. 0.219%.

Thus, too high values can be found in the determination of free formic acid for two reasons. On the other hand, the values obtained for the esteric formic acid are flawless, since neither the sugar color nor the sugar decomposition can be considered here. The values found for formic acid in ester form can only be determined by the original rum or by artificial rum esters.

After various experiments it seems impossible that the excess that can be found in the determination of free formic acid will exceed 2 mg for 100 cc. This value respectively for 0.5 cc 1/10 N. lye is therefore to be subtracted from the amount of free or total formic acid in rum blends, real and alleged, when calculating their ratio to the amount of ester. This has happened in the last column of numbers in the table; the penultimate column shows the values ​​without correction. Also, when comparing the free formic acid with other values ​​one will have to consider how much their real value may possibly be lower. The fact that the proposed correction is more than sufficient indicates that the levels of free formic acid found in the Ruin Blends under investigation, in which the rum from the original rum is included, do not reach the level of correction. In addition, in many cases tar dye and no sugar color is used for coloring. As a result, the ester related corrected ratios, which would actually have to be in the same amount as the original rum – between 2.0 and 6.4 – do not have any positive values ​​for the rum blends listed.

Looking at the results of the examination of the original rum samples, the following results are obtained: Fragrance was always high, tar dye was never present. The alcohol content varied between 55.9 and 61.6 g in 100 cc, the amount of ester between 30.0 and 87.2 1/10-mg equivalents for 100 cc. The content of free and ester of formic acid was quite similar for all samples. In 100 cc, I found 3.28 to 5.03 mg of free formic acid respectively 0.71 to 1.09 1/10-mg equivalents, of ester-formic acid 3.34 to 4.45 mg or 0.73 to 0.97 1/10-mg equivalents. There were 50 to 144 1/10-mg equivalents of ester, 1.2 to 1.9 1/10 mg equivalents of free formic acid and 1.2 to 1.6 1/10-mg equivalents of bound formic acid per 100 g of alcohol. 2.0 to 6.4 parts of total formic acid were calculated on 100 parts of ester.

The Rumverschnitte all showed the typical perfume. In part, they were dyed with tar dye. Values ​​for esters were low, ranging from 0.75 to 2.4 1/10 mg equivalents apart from the home-made blend (No.9 of the Table), which showed a higher value – 4.6 1/10-mg equivalents , However, part of the samples (Nos. 7 and 8) were made from the two ester-poorest of the original rum samples listed. The values ​​for free formic acid increased to 1.03 mg in tar-color-stained rum blends, and to 1.71 mg in 100 cc for those caramel-stained. It has already been stated that a correction should be made here. In the calculation of the alcohol content, the error is less important because the alcohol content is considerably greater; in the calculation of the usually very low ester content, it appears essentially as the penultimate column of numbers in the table shows. The mixture I produced (No. 9) had no added extractives and caramel; Here, therefore, I found only the small amount of formic acid, which originated from the original rum, and which theoretically had to be 0.23 mg in 100 cc.

Ester-formic acid was found only in traces in the blends; as such, levels were considered below 0.5 mg; in one case (No. 10) the amount has been weighed. The findings thus coincide with the theoretical requirement.

The Kunstrum samples had in part been marketed under designations that suggested a better product. One of the samples showed Rum aroma clearly. Two more samples appeared to have received very little added rum. They contained 18.5 to 33.1 g of alcohol in 100 cc and with one exception tar dye. The content of esters varied widely between 4.2 and 21.2 1/10-mg equivalents; Accordingly, the ratio of esters to alcohol varied between 13.7 and 87.2. For the majority of Kunstrum samples, the alcohol-related ester content was within the limits of unblended rum; in no case did it sink to the values ​​found in the Rumverschnitten purchased. Apart from the failure of the fragrance sample, in most cases the values ​​found for formic acid, especially the ratio of free and total formic acid to alcohol and the ratio of total formic acid to esters, indicate that artifacts are present. 2.68 to 26.01 mg were found on free formic acid, traces of up to 4.84 mg in 100 cc of ester-formic acid were found. Striking is also the preponderance of free formic acid over the ester formic acid; with the original rum, both values ​​are approximately the same. In the case of artificial rum essences, a greater percentage of the esters are in general formic acid esters; above all they contain much free formic acid, since apparently poorly esterified preparations are used. The investigation of two ruin counts confirmed this.

In many cases, a proper assessment of rum without the determination of free and bound formic acid will be possible. That these provisions can sometimes serve well, however, is shown above all by sample no. 14. In the presence of rum and artificial rum, the presence of formic acid makes the assessment very easy. In the dependence of the formic acid content of the respective composition of the artificial Rum essence lies naturally a lack of the procedure – the possibility of the failure.

1) According to the manufacturer, 10% of the alcohol is made from rum alcohol of the original Jamaican rum II.
2) According to the manufacturer, 14% of the alcohol is made from rum alcohol of the original Jamaican rum III.
3) Self-made waste containing 5% of original Jamaican rum IV so that 10% of the alcohol is rum alcohol.

4) The samples no. 13 and 14 are from the same manufacturer, according to which f-Rum “Faconrum” and ff-Rum mean “Fine Faconrum” and according to whose confession the sample no. 13 Kunstrum and the sample no. 14 Kunstrum with Rumzusatz is.
5) In cases in which calculation of the total formic acid was not possible due to the minority of ester-formic acid, maximum values were used in accordance with the method; at the sample no. 18 was based on the lowest value of the calculation.

The number of original rum samples examined in the manner indicated is still small; It is therefore to be expected that in further investigations, somewhat greater fluctuations in the values of free formic acid present in ester form will be found. Therefore, it is desirable that further material in this direction is provided by the professionals.

Operation Rum Babelfish, A bibliography

Sponsor my distilling work simply by sharing the artisan workshop of the Bostonapothecary on social media. Copy, Paste, Support!

Operation Rum Babel Fish is a project to collect, translate, unify, annotate, and link all the world’s great papers on rum technology.

Authors will use the papers to dazzle us with new tellings of spirit histories. The marketing departments of old producers will open up a little more as history gets filled in and we’re all less inclined to swallow shit. New producers will emerge informed and energized by their predecessors, so we’ll no doubt see new fine rums.

What we’re finding is that rum is especially well studied, more so than any other spirit category, and has always been incredibly progressive. One scientist, exploring Batavia Arrak (discovered in this bibliography), went on to win a Nobel. We can also attach first names to so many ideas and see that rum thinkers back then were probably better connected and more familiar with each other’s works than we are today.

Below in two parts are excerpts of a bibliography created by sugar technologist, Hubert Von Olbrich, for the 1975 rum symposium. The original bibliography has entries in English, Spanish, French, and German. For this post, I tossed out the English entries and the Spanish entries I’ve already covered (such as Arroyo). I then took the French and the German and translated the titles. The second complete part is at the bottom of this document and may inform someone who is curious what I narrowed down from. The first part, separated by a line break, are citations I singled out as the most promising. I either linked to the originals which need translated or added annotations to help locate the others. Some are challenging and will require some serious library sleuthing.

One citation already proved worth all the work and was even found already translated. This work, by the Nobel prize winning scientist describes Batavaia arrak as a Schizosaccharomyces Pombe rum that has a symbiotic fermentation from the added rice and describes the process. This is very different than previously understood and points to our hero Pombe yet again. What else will we find?

Nicola Gref already helped reveal some extra juicy bits by annotating the Olbrich’s chapter in German from his 1970’s History of Molasses. Stephan Berg from the Bitter Truth is working on the 1936 German language document Olbrich singled out as extra important.

We can have a lot of confidence in Olbrich’s bibliography, but we already know he didn’t find everything. He was however German, and besides a technologist, he was also a historian and bibliophile. Therefore, Olbrich is our best shot at knowing what has been published in the German language that has been hard to reach.

Laying eyes on juicy historical information for the very first time is incredibly rewarding. If you want to get in on the game and help reveal important bits of spirits history, feel free to track down some of the citations and translate them. Comment on anything you’re working on.

Right now I’m working on all 30 years of French papers from the INRA. Next up I’m going to tackle all the citations from the Rum Pilot Plant that pertain to rum aroma (I have their annotated bibliography). Then I’ll dig back into what ever is left here. The BPL is also about to send me the 150 pages of papers presented at the 1975 rum symposium, many of which will need translated.

To quote Olbrich before we commence:

It is an irrefutable fact that a library is cheaper than a laboratory and that inquiries are far less costly than investments in development work which is already being carried out elsewhere. By means of thorough information regarding the basic position of science and technique, irrational brain-work is avoided, fruitless researching and inventing activities are prevented and the squandering of economic power and capital is hindered. With other words: Ascertainment of which results and suggestions have already been published in order to solve a problem, serves the rationalization and increase in the productivity of science and practice. Unproductive searching, idle effort and erroneous investments are thus avoided.

Andres M. Notes sur l’évolution des installations de production des rhums. Industries alimentaires et agricoles. Juillet-aoüt (1970), p. 901-906.
Notes on the evolution of rums production facilities. July-August
[This is an easy ILL]

Anonymous. Distillation des mélasses pour la fabrication des tafias et des rhums, Sucrerie Indigène 6, (1871/72) p. 486-491.
Distillation of molasses for making tafias and rums
[original French. This actually looks worth translating and has some great illustrations.]

Anonymous. Rum production in Madeira. Facts about Sugar 14 (1922), p. 401.
[The article turned out to be a snippet about reducing produce size so the link above is an image of it.]

Anonymous. Die Fabrikation des Jamika-Rums und des Batavia-Arraks (Ein Überblick über die wichtigsten Originalarbeiten, besonders englischer und holländischer Forscher). Deutsche Destillateur-Zeitung 57 (1936), n0. 29, p. 114, no 3o, p. 123-124, no 35, p. 145-146, no 38, p. 159, no 43/44, p. 182-183, no 5o, p. 205-206 (with 27 literature references).
The Fabrication of Jamaica Rum and Batavia Arraks (A Review of the Most Important Original Works, Especially English and Dutch Researchers)

Anonymous. Aussichten auf die Rumherstellung aus Zuckerrohr in Spanien, Prager Zuckermarkt. p. 31, supplement to Z. Zuckind. CSR 66 (3) (1942/43).
Outlook on rum production from sugarcane in Spain

Boes J. Über das Vorkommen von Aminen in Arrak und Rum. Apoth. Ztg. 22 (1907), p. 56.
About the occurrence of amines in arrak and rum
[Apotheker Zeitung link to entire issue scanning] [image of the short article page] [higher up link to use as a resource]

Bonis A. Untersuchungen über die Zusammensetzung der Rume von Martinique, Oesterr. Ung. Z. Zuckerind. Landw. NF 39 (1910), p. 6oo.
Studies on the composition of the rums of Martinique [Österreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirtschaft]

Brauer K. Deutscher Rum, Chem. Ztg. 46 (1922), p. 161-163, 185-186; Z. Ver. Zucker-ind. 73 (1923), p. 332-333; Deutscher Arrak, Chem. Ztg. 47 (1923), p. 365-367.
German rum / German Arrak [Chemiker-Zeitung]

Comite consultatif durhum. Rapport du groupe d’experts sur les problèmes posés par l’intégration du rhum dans le Marché Commun, C. C. R., juillet 197o, 45 p. ronéotées, annexes.
Report of the group of experts on the problems posed by the integration of rum into the Common Market

Eijkman C. Mikrobiologisches über Arrakfabrikation in Batavia, Zbl. Bakteriol. Parasitenkunde, 1. Abt., 16 (1894), p. 97-103.
Microbiological about Arrak fabrication in Batavia
[This is a wildly important paper and the above link is to it translated and explained.]

Ficker M., Szus S. Über Rumgärung, Zent. Bakt. Parasit. 82 (1930), p. 199-214.
About rum fermentation [Zentralblatt für Bakteriologie, Parasitenkunde]

Fincke E. Über die Unterscheidung von Jamaikarum und Kunstrum, Z. Unters. Nahr. Genussm. 25 (1913), p. 589-596.
About the distinction between Jamaikarum and Kunstrum
[My translation]

Guillaume J. Untersuchungen über das Rum-Aroma, Bull. Assoc. Chimistes 58 (1941), p. 163-174; Ztschr. Wirtschaftsgr. Zuckerind. 93 (1943), p. 50-52.
Studies on the rum flavor

Haeseler G. Neuere Arbeiten über Rumfabrikation, Branntweinwirt Schaft 3 (1949), p. 180-181.
Recent work on rum production

2. Saito K. Notiz über die Melasserumgärung auf den Bonininseln, Österreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirschaft 37 (1908), p. 918.
Note about the molasses fermentation on the Bonin Islands, Austro-Hungarian magazine for sugar industry and agriculture
[The above link is my translation. This article is important because it acknowledges a film yeast rum.]

3. Bonis A. Untersuchungen über die Zusammensetzung der Rume von Martinique, Österreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirtschaft 39 (1910), p. 600.
Studies on the composition of Martinique’s rums, Austro-Hungarian magazine for sugar industry and agriculture

4. Simon A. Untersuchungen über die Einteilung der Rume von Martinique nach ihrem Verunreinigungskoeffizienten, Osterreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirtschaft 39 (1910), p. 600-601.
Investigations on the classification of the areas of Martinique according to their impurity coefficient, Austrian-Hungarian magazine for sugar industry and agriculture

5. Brauer K. Deutscher Arrak (Chemiker-Zeitung no 51/52, 1923) ), Zeitschrift des Vereins der Deutschen Zucker-Industrie 73 (NF. 60) (1923), P. 332-333.
German Arrak-Journal of the Association of the German Sugar Industry

6. Winkelhausen W. Verfahren zur Vorbereitung von Zuckerlösungen beliebiger Herkunft zur Herstellung einer Maische für Rum- oder Arrakdestillate, DRP no 106 654; Deutsche Zuckerindustrie 67 (1942), p. 47.
Process for preparing sugar solutions of any origin for making a mash for rum or arrak-distillates

3. V[on] S. Rum aus Jamaika. Wasser aus Schottland, Branntweinwirtschaft 78 (1956), no 3, p. 51-52.
Rum from Jamaica. Water from Scotland

4. anonymous. Bundesrepublik grösster Rum-Mark der Welt, Branntweinwirtschaft 105 (1965), no 7, p. 174.
Federal Republic of the world’s largest Rum-Market

Jayatunge N., Fernando QU. Änderungen in der chemischen Zusammensetzung des Arraks während der Reifung. Euclides (Madrid) II (1951), P. 404-406 ; rev. : Chem. Zbl. (1954) II, 5872.
Changes in the chemical composition of the arraks during maturation

Jonscher A. Zur Kenntnis und Beurteilung von Rum, Rumverschnittenund Kunstrum, Z. Öffentl. Chem. 20 (1914), p. 329-336, 345-349.
For the knowledge and evaluation of rum, Rumverschnitten and Kunstrum
[untranslated German] [my translation]

Lebbin. Ein neuer Weg zur Beurteilung von Rum und Arrak. Chem. Ztg. 50 (1926), p. 334.
A new way to judge rum and Arrak [Chemisches Zentralblatt]

Luckow C. Was verstehe man unter der « Esterzahl » beim Original-Rum, Mitt. ATL 2o (1930), no 1, p. 28-29, 31 (1941), no 2, p. 5.
What is meant by the “ester number” of the original rum?

Luckow C. Über die Begutachtung von Rum, Arrak und Kirschwasser mit Hilfe der Ausgiebigkeitsprobe, Brennerei-Ztg. 50 (1933), 86-87.
On the evaluation of rum, arrack and kirsch with the help of the exhaustive test
[this should be easily ILL requestable]

OLBRICH H. Über die Arrak-Gewinnung aus Rohrmelasse, DestillateurLehrling II (1961), p. 57-62 (Supplement to Branntweinwirtschaft) ; rev. : Z. Zuckerind. 13 (1963), p. 236.
About the arrack extraction from molasses

Rose L. Die Alkohol- und Rumfabrikation in Costa Rica, Z. Spiritusind. 51 (1928), p. 194-195.
The alcohol and rum production in Costa Rica

Schaffer E. Geruchsprüfung von Rum, Chem. Ztg. 44 (1923), p. 934.
Odor test of rum [Chemiker-Zeitung (this should be ILL gettable)]

Simon A. Untersuchungen über die Einteilung der Rume von Martinique nach ihrem Verunreinigungskoeffizienten, Oesterr. Ung. Z. Zuckerind. Landw. NF 39 (1910), p. 600-601.
Studies on the classification of Martinique’s rums according to their contamination coefficient

WALTER E. Die Grogprobe, ein Hilfsmittel zur Beurteilung von Rum und Arrak, Alkohol-Industrie (1953), no 7, P. 165.
The grog sample, a tool for evaluating rum and arrack

Wollny G. Martinique-Rum [aus Zuckerrohrsaft und/oder Rohrmelasse], Alkohol-Industrie 77 (1964), no 2, p. 47-49.
Martinique rum from sugar cane juice and / or molasses

Wrede F. Die Rumbrennerei in Übersee und in Deutschland, Z. Spiritusind. 51 (1928), p. 150.
The Rum distilleries overseas and in Germany

Wüstenfeld H., Luckow C. Zur Frage der Begutachtung von Auslandsrum und Arrak, Korrespondenz ATL (Abteilung Trinkbranntwein und Likörfabrikation im Institut für Gärungsgewerbe Berlin) 18 (1928), p. 23-25.
On the question of the assessment of foreign rum and Arrak

Wüstenfeld H. Luckow C. Esterzahl, Ausgiebigkeit und Qualitat von rum und Arrak sorten des Handels, Mitt. der ATL 20 (1930), no 1, p. 2-6.
Ester number, abundance and quality of rum and arrak types of trade
[here is something (page 129) these two did together on vacuum distillation of beverage stuff. It looks like Curt Luckow wrote lots of abstract for this journal and may have been a major German thinker.]


Andres M. Notes sur l’évolution des installations de production des rhums. Industries alimentaires et agricoles. Juillet-aoüt (1970), p. 901-906.
Notes on the evolution of rums production facilities. July-August

Anonymous. Distillation des mélasses pour la fabrication des tafias et des rhums, Sucrerie Indigène 6, (1871/72) p. 486-491.
Distillation of molasses for making tafias and rums

Aanonymous. Rum production in Madeira. Facts about Sugar 14 (1922), p. 401.

Anonymous. Die Fabrikation des Jamika-Rums und des Batavia-Arraks (Ein Überblick über die wichtigsten Originalarbeiten, besonders englischer und holländischer Forscher). Deutsche Destillateur-Zeitung 57 (1936), n0. 29, p. 114, no 3o, p. 123-124, no 35, p. 145-146, no 38, p. 159, no 43/44, p. 182-183, no 5o, p. 205-206 (with 27 literature references).
The Fabrication of Jamaica Rum and Batavia Arraks (A Review of the Most Important Original Works, Especially English and Dutch Researchers)

Anonymous. Aussichten auf die Rumherstellung aus Zuckerrohr in Spanien, Prager Zuckermarkt. p. 31, supplement to Z. Zuckind. CSR 66 (3) (1942/43).
Outlook on rum production from sugarcane in Spain

Boes J. Über das Vorkommen von Aminen in Arrak und Rum. Apoth. Ztg. 22 (1907), p. 56.
About the occurrence of amines in arrak and rum

Bonis A. Untersuchungen über die Zusammensetzung der Rume von Martinique, Oesterr. Ung. Z. Zuckerind. Landw. NF 39 (1910), p. 6oo.
Studies on the composition of the rums of Martinique

Brauer K. Deutscher Rum, Chem. Ztg. 46 (1922), p. 161-163, 185-186; Z. Ver. Zucker-ind. 73 (1923), p. 332-333; Deutscher Arrak, Chem. Ztg. 47 (1923), p. 365-367.
German rum / German Arrak

Comite consultatif durhum. Rapport du groupe d’experts sur les problèmes posés par l’intégration du rhum dans le Marché Commun, C. C. R., juillet 197o, 45 p. ronéotées, annexes.
Report of the group of experts on the problems posed by the integration of rum into the Common Market

Eijkman C. Mikrobiologisches über Arrakfabrikation in Batavia, Zbl. Bakteriol. Parasitenkunde, 1. Abt., 16 (1894), p. 97-103.
Microbiological about Arrak fabrication in Batavia

Ficker M., Szus S. Über Rumgärung, Zent. Bakt. Parasit. 82 (1930), p. 199-214.
About rum fermentation

Fincke E. Über die Unterscheidung von Jamaikarum und Kunstrum, Z. Unters. Nahr. Genussm. 25 (1913), p. 589-596.
About the distinction between Jamaikarum and Kunstrum

Guillaume J. Untersuchungen über das Rum-Aroma, Bull. Assoc. Chimistes 58 (1941), p. 163-174; Ztschr. Wirtschaftsgr. Zuckerind. 93 (1943), p. 50-52.
Studies on the rum flavor

Haeseler G. Neuere Arbeiten über Rumfabrikation, Branntweinwirt Schaft 3 (1949), p. 180-181.
Recent work on rum production

2. Saito K. Notiz über die Melasserumgärung auf den Bonininseln, Österreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirschaft 37 (1908), p. 918.
Note about the molasses fermentation on the Bonin Islands, Austro-Hungarian magazine for sugar industry and agriculture

3. Bonis A. Untersuchungen über die Zusammensetzung der Rume von Martinique, Österreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirtschaft 39 (1910), p. 600.
Studies on the composition of Martinique’s rums, Austro-Hungarian magazine for sugar industry and agriculture

4. Simon A. Untersuchungen über die Einteilung der Rume von Martinique nach ihrem Verunreinigungskoeffizienten, Osterreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirtschaft 39 (1910), p. 600-601.
Investigations on the classification of the areas of Martinique according to their impurity coefficient, Austrian-Hungarian magazine for sugar industry and agriculture

5. Brauer K. Deutscher Arrak (Chemiker-Zeitung no 51/52, 1923) ), Zeitschrift des Vereins der Deutschen Zucker-Industrie 73 (NF. 60) (1923), P. 332-333.
German Arrak-Journal of the Association of the German Sugar Industry

6. Winkelhausen W. Verfahren zur Vorbereitung von Zuckerlösungen beliebiger Herkunft zur Herstellung einer Maische für Rum- oder Arrakdestillate, DRP no 106 654; Deutsche Zuckerindustrie 67 (1942), p. 47.
Process for preparing sugar solutions of any origin for making a mash for rum or arrak-distillates

3. V[on] S. Rum aus Jamaika. Wasser aus Schottland, Branntweinwirtschaft 78 (1956), no 3, p. 51-52.
Rum from Jamaica. Water from Scotland

4. anonymous. Bundesrepublik grösster Rum-Mark der Welt, Branntweinwirtschaft 105 (1965), no 7, p. 174.
Federal Republic of the world’s largest Rum-Market

Jayatunge N., Fernando QU. Änderungen in der chemischen Zusammensetzung des Arraks während der Reifung. Euclides (Madrid) II (1951), P. 404-406 ; rev. : Chem. Zbl. (1954) II, 5872.
Changes in the chemical composition of the arraks during maturation

Jonscher A. Zur Kenntnis und Beurteilung von Rum, Rumverschnittenund Kunstrum, Z. Öffentl. Chem. 20 (1914), p. 329-336, 345-349.
For the knowledge and evaluation of rum, Rumverschnittenund Kunstrum

Lebbin. Ein neuer Weg zur Beurteilung von Rum und Arrak. Chem. Ztg. 5o (1926), p. 334.
A new way to judge rum and Arrak

Luckow C. Was verstehe man unter der « Esterzahl » beim Original-Rum, Mitt. ATL 2o (1930), no 1, p. 28-29, 31 (1941), no 2, p. 5.
What is meant by the “ester number” of the original rum?

Luckow C. Über die Begutachtung von Rum, Arrak und Kirschwasser mit Hilfe der Ausgiebigkeitsprobe, Brennerei-Ztg. 50 (1933), 86-87.
On the evaluation of rum, arrack and kirsch with the help of the exhaustive test

OLBRICH H. Über die Arrak-Gewinnung aus Rohrmelasse, DestillateurLehrling II (1961), p. 57-62 (Supplement to Branntweinwirtschaft) ; rev. : Z. Zuckerind. 13 (1963), p. 236.
About the arrack extraction from molasses

Rose L. Die Alkohol- und Rumfabrikation in Costa Rica, Z. Spiritusind. 51 (1928), p. 194-195.
The alcohol and rum production in Costa Rica

Schaffer E. Geruchsprüfung von Rum, Chem. Ztg. 44 (1923), p. 934.
Odor test of rum

Simon A. Untersuchungen über die Einteilung der Rume von Martinique nach ihrem Verunreinigungskoeffizienten, Oesterr. Ung. Z. Zuckerind. Landw. NF 39 (1910), p. 600-601.
Studies on the classification of Martinique’s rums according to their contamination coefficient

WALTER E. Die Grogprobe, ein Hilfsmittel zur Beurteilung von Rum und Arrak, Alkohol-Industrie (1953), no 7, P. 165.
The grog sample, a tool for evaluating rum and arrack

Wollny G. Martinique-Rum [aus Zuckerrohrsaft und/oder Rohrmelasse], Alkohol-Industrie 77 (1964), no 2, p. 47-49.
Martinique rum from sugar cane juice and / or molasses

Wrede F. Die Rumbrennerei in Übersee und in Deutschland, Z. Spiritusind. 51 (1928), p. 150.
The Rum distilleries overseas and in Germany

Wüstenfeld H., Luckow C. Zur Frage der Begutachtung von Auslandsrum und  Arrak, Korrespondenz ATL (Abteilung Trinkbranntwein und Likörfabrikation im Institut für Gärungsgewerbe Berlin) 18 (1928), p. 23-25.
On the question of the assessment of foreign rum and Arrak

Wüstenfeld H. Luckow C. Esterzahl, Ausgiebigkeit und Qualitat von rum und Arrak sorten des Handels, Mitt. der ATL 20 (1930), no 1, p. 2-6.
Ester number, abundance and quality of rum and arrak types of trade

The list adapted from Olbrich

Andres M. Notes sur l’évolution des installations de production des rhums. Industries alimentaires et agricoles. Juillet-aoüt (1970), p. 901-906.
Notes on the evolution of rums production facilities. July-August

Anonymous. Die Fabrikation des Rums in Indien, Hermbstädts, Bulletin 15 (1813), no 3, p. 268-273.
The fabrication of Indian rums. [probably West Indian]

Anonymous. Distillation des mélasses pour la fabrication des tafias et des rhums, Sucrerie Indigène 6, (1871/72) p. 486-491.
Distillation of molasses for making tafias and rums

Aanonymous. Rum production in Madeira. Facts about Sugar 14 (1922), p. 401.

Anonymous. Die Fabrikation des Jamika-Rums und des Batavia-Arraks (Ein Überblick über die wichtigsten Originalarbeiten, besonders englischer und holländischer Forscher). Deutsche Destillateur-Zeitung 57 (1936), n0. 29, p. 114, no 3o, p. 123-124, no 35, p. 145-146, no 38, p. 159, no 43/44, p. 182-183, no 5o, p. 205-206 (with 27 literature references).
The Fabrication of Jamaica Rum and Batavia Arraks (A Review of the Most Important Original Works, Especially English and Dutch Researchers)

Anonymous. Aussichten auf die Rumherstellung aus Zuckerrohr in Spanien, Prager Zuckermarkt. p. 31, supplement to Z. Zuckind. CSR 66 (3) (1942/43).
Outlook on rum production from sugarcane in Spain

Anonymous. Das Rechnen mit Proofgallonen und Proofgraden, Alkohol Industrie 7o (1957), no 18, p. 423.
Computing with proof gallons and proof grades

Anonymous. Die Historie vom Rum, Pott-Kompass 1967, no 3 and 4; 1968, no 2 and 3 (conglomeration).
The history of rum.

Anonymous. Berichte vom Rum-Markt. Kompass 1967, 1968 (conglomeration)
Reports from the rum market

Anonymous. Le rhum. Le Guide de l’Épicier, Avril I968, p. 9-19.
The rum. The Grocer’s Guide

Banc d’essai. Le Rhum. Le nouveau guide Gault et Millau, février 197o, p. 23-27.
The rum. The new Gault and Millau guide

Baraud J., Maurice A., Die höheren Alkohole und die leichten Ester von Rums und Apfelbranntweinen (Les alcools et esters des eaux-de-vie de canne et de pomme). Industrie Alimentaires et Agricoles 80 (1963) 3-7; rev. : Branntweinwirtschaft 103 (1963), 338.
The higher alcohols and the light esters of rums and apple brandies (Les alcools et ales des eaux-de-vie de canne et de pomme)

Bardinet. Bardinet-Négrita, symbole international du rhum français, Bordeaux S. d., 32 p. ill.
Bardinet-Négrita, international symbol of French rum

BLOME R. Englisches America, oder kurtze doch deutliche Beschreibung aller derer denigen Länder und Inseln so der Cron Engeland in Westindien jetziger Zeit zuständig und unterthanig sind: dass sie zeithero von den Franzosen und Englischen des verfluchten Trankes erlernet haben, den man Rum, Rumbullion, oder Ribtdevil, Mortteufel nennet, so noch stärker ist als Weinhefen-Brantwein, und von überbliebener Unreinigkeit des Zuckers und Zuckerrohrs abgezogen und zugerrichtet wird, 1697.
English America, or have a clear description of all these countries and islands, so the Crown England in western India are responsible and subject: that they have learned from time to time the French and English of the cursed potion known as Rum, Rumbullion, or Ribtdevil, Mortteufel, even more so than Weinhefen-Brantwein, is called and stripped of all the uncleanliness of sugar and sugar cane, 1697.

Boes J. Über das Vorkommen von Aminen in Arrak und Rum. Apoth. Ztg. 22 (1907), p. 56.
About the occurrence of amines in arrak and rum

Bonis A. Untersuchungen über die Zusammensetzung der Rume von Martinique, Oesterr. Ung. Z. Zuckerind. Landw. NF 39 (1910), p. 6oo.
Studies on the composition of the rums of Martinique

Brauer K. Deutscher Rum, Chem. Ztg. 46 (1922), p. 161-163, 185-186; Z. Ver. Zucker-ind. 73 (1923), p. 332-333; Deutscher Arrak, Chem. Ztg. 47 (1923), p. 365-367.
German rum / German Arrak

Bremer W. Trinkbranntwein und Likör. 1st Edition 1918; Leipzig : 2nd Edition.
Drinking liquor and liqueur

de Corn. Mode de fabrication du rhum, French Pat. 32956 ; Catalogue 1857, p. 18o.
Method of making rum

CEDAL (Centre de Documentation de l’Alimentation, Paris). Histoire de la canne à sucre et du rhum. Economie Familiale no 22, printemps-été 197o, p . 9-IO .
History of sugar cane and rum

CEDAL (Paris). Richesses françaises d’Outre-Mer, la canne à sucre et le rhum, 1971, 16 p. ; see Z. ZuckInd. 23 (1973) 1, p. 39.
French overseas riches, sugar cane and rum

CEDAL (Paris). Le Rhum. Documentation pratique du CEDAL, 1971, 91 p. with numerous illustrations and tables; see Z. ZuckInd. 23 (1973), p. 39.

Charpentier De Cossigny J. F. Mémoire sur la fabrication des eaux-de-vie de sucre, 1781 (with Supplément, 1782); (an early Mauritian imprint).
Brief on the manufacture of sugar spirits

Commissariat general du plan d’euipment et de la productivite, Réponse au questionnaire de l’intergroupe alcools-boissons alcooliques, VI° plan, avril 1970, 18 p. dactylographiées.
Response to the intergroup alcohol-alcoholic drinks questionnaire

Comite consultatif durhum. Rapport du groupe d’experts sur les problèmes posés par l’intégration du rhum dans le Marché Commun, C. C. R., juillet 197o, 45 p. ronéotées, annexes.
Report of the group of experts on the problems posed by the integration of rum into the Common Market

Comite national Interprofessionnel du rhum. Le rhum, définitions françaises; C. N. I. R., janvier 1965, 64 p.
Rum, French definitions

Cousins H. H. Landwirtschaftliches und Technisches aus der Versuchsstation für Zuckerindustrie in Jamaika, Oesterr. Ung. Z. Zuckerind. Landw., NF 35 (1906), p. 632-634.
Agricultural and Technical from the sugar industry experimental station in Jamaica

Davies J. G. Anwendung von Trockenhefe in Jamaica-Rum-Brennereien, Chem. Abstr. (1952) 9248; Proc. Brit. West Indies Sugar Technol. (1948), p. 23-27; rev. : Branntweinwirtschaft 75 (1953), p. 77.
Use of dry yeast in Jamaican rum distilleries

Direction Des Douanes. Statistiques du commerce extérieur des départements d’Outre-Mer; différents bulletins.
Customs Direction. Foreign Trade Statistics of Overseas Departments

Dormoy Estienne. L’économie sucrière des départements d’Outre-Mer. Institut des Hautes-Études du droit rural et d’Économie Agricole 197o, 25o p. roméotées.
The sugar economy of the overseas departments

Eijkman C. Mikrobiologisches über Arrakfabrikation in Batavia, Zbl. Bakteriol. Parasitenkunde, 1. Abt., 16 (1894), p. 97-103.
Microbiological about Arrak fabrication in Batavia

Federation nationale des producteurs de rhum. Le rhum dans le Marché Commun, décembre 1964, 64 p.
Rum in the Common Market

Fellenberg Th. von. Über den Jamaikarum und seine höheren Alkohole, Mitt. Lebensmittel-Hyg. 1 (1910), p. 352-357.
About the Jamaika rum and its higher alcohols

Ficker M., Szus S. Über Rumgärung, Zent. Bakt. Parasit. 82 (1930), p. 199-214.
About rum fermentation

Fincke E. Über die Unterscheidung von Jamaikarum und Kunstrum, Z. Unters. Nahr. Genussm. 25 (1913), p. 589-596.
About the distinction between Jamaikarum and Kunstrum

Gaber A. Die Fabrikation von Rum, Arrak und Cognac. Leipzig: Hartleben, 1898 (1st Edition); Die Fabrikation von Rum, Arrak, Kognak. 2nd Edition, Wien/Leipzig, 1923.
The fabrication of rum, arrack and cognac

Guillaume J. Untersuchungen über das Rum-Aroma, Bull. Assoc. Chimistes 58 (1941), p. 163-174; Ztschr. Wirtschaftsgr. Zuckerind. 93 (1943), p. 50-52.
Studies on the rum flavor

Haeseler G. Neuere Arbeiten über Rumfabrikation, Branntweinwirt Schaft 3 (1949), p. 180-181.
Recent work on rum production

Harman C. Les Antilles. Collection Life autour du monde. Time-Life, 1969, 157 p. ill.
West Indies. Life collection around the world

Hermbstädt S. F. Die Fabrikation des Rums in Indien, Bulletin des Neuesten und Wissenswürdigsten aus der Naturwissenschaft 15 (1813), no 3, p. 268-273.
The production of rum in India, Bulletin of the newest and most worth knowing from the natural sciences

Herzfeld A. Bericht über die Versuche zur Darstellung Rum-artiger Produkte aus Rübensaft, Melasse und Rohzucker, Zeitschrift des Vereins für die Rübenzucker-Industrie des Deutschen Reiches 27. N. F.; 4o (1890), p. 645-680 ; Oest.-Ung. Z. Zuckerind. Landw. NF 20 (1891), p. 124-128.
Report on the attempts to present rum-like products from beet juice, molasses and raw sugar, Journal of the Association for the beet sugar industry of the German Reich

Institut Für Zuckerindustrie (IZI), Berlin. Compilation of some Rum Papers from the years 1906, 1908, 1910, 1923, 1942. Contents.

1. Cousins H. H. Landwirtschaftliches und Technisches insbesondere über Rumfabrikation aus der Versuchsstation für Zuckerindustrie in Jamaika, Oesterreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirtschaft 35 (1906), p. 632-634.
Agricultural and technical in particular on rum production from the experimental station for sugar industry in Jamaica, Austrian-Hungarian magazine for sugar industry and agriculture

2. Saito K. Notiz über die Melasserumgärung auf den Bonininseln, Österreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirschaft 37 (1908), p. 918.
Note about the molasses fermentation on the Bonin Islands, Austro-Hungarian magazine for sugar industry and agriculture

3. Bonis A. Untersuchungen über die Zusammensetzung der Rume von Martinique, Österreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirtschaft 39 (1910), p. 600.
Studies on the composition of Martinique’s rums, Austro-Hungarian magazine for sugar industry and agriculture

4. Simon A. Untersuchungen über die Einteilung der Rume von Martinique nach ihrem Verunreinigungskoeffizienten, Osterreichisch-Ungarische Zeitschrift für Zuckerindustrie und Landwirtschaft 39 (1910), p. 600-601.
Investigations on the classification of the areas of Martinique according to their impurity coefficient, Austrian-Hungarian magazine for sugar industry and agriculture

5. Brauer K. Deutscher Arrak (Chemiker-Zeitung no 51/52, 1923) ), Zeitschrift des Vereins der Deutschen Zucker-Industrie 73 (NF. 60) (1923), P. 332-333.
German Arrak-Journal of the Association of the German Sugar Industry

6. Winkelhausen W. Verfahren zur Vorbereitung von Zuckerlösungen beliebiger Herkunft zur Herstellung einer Maische für Rum- oder Arrakdestillate, DRP no 106 654; Deutsche Zuckerindustrie 67 (1942), p. 47.
Process for preparing sugar solutions of any origin for making a mash for rum or arrak-distillates

Institut Für Zuckerindustrie, Berlin. Compilation of some Papers about Rum and Rum-Fabrication from the years 1949 till 1967; Contents:

1. [Hae S[eler). Neuere Arbeiten über Rum-fabrikation, Branntweinwirtschaft 3 (1949), no 12, p. 180-181.
Recent work on rum manufacturing

2. Bausch. Rum aus Britisch-Westindien, Branntweinwirtschaft 76 (1954), no 2, p. 27.
Rum from British West Indies

3. V[on] S. Rum aus Jamaika. Wasser aus Schottland, Branntweinwirtschaft 78 (1956), no 3, p. 51-52.
Rum from Jamaica. Water from Scotland

4. anonymous. Bundesrepublik grösster Rum-Mark der Welt, Branntweinwirtschaft 105 (1965), no 7, p. 174.
Federal Republic of the world’s largest Rum-Market

5. Alten Hofen G. Die Wettebewerbssituation auf dem deutschen Rum Markt, Branntweinwirtschaft 1o5 (1965), no 15, p. 407.
The competitive situation on the German rum market

6. Fedders and Dubick. Noch einmal : Die Wettbewerbssituation auf dem deutschen Rum-Markt, Branntweinwirtschaft 1o5 (1965), no 2o, p. 558, 560.
Once again: The competitive situation in the German rum market

7. RATHKE. Bundesmonopolverwaltung für Branntwein zur Einfuhr von Rum, Branntweinwirschaft 1o7 (1967), no 9, p. 219-220.
Federal Monopoly Administration for spirits for the import of rum

Jayatunge N., Fernando QU. Änderungen in der chemischen Zusammensetzung des Arraks während der Reifung. Euclides (Madrid) II (1951), P. 404-406 ; rev. : Chem. Zbl. (1954) II, 5872.
Changes in the chemical composition of the arraks during maturation

Jonscher A. Zur Kenntnis und Beurteilung von Rum, Rumverschnittenund Kunstrum, Z. Öffentl. Chem. 20 (1914), p. 329-336, 345-349.
For the knowledge and evaluation of rum, Rumverschnittenund Kunstrum

Kappeller G., Schulze R. Beitrag zur Rumuntersuchung, Pharm. Ze. tralhalle 51 (1910), p. 165-170.
Contribution to the Rumuntersuchung

Kohut. Kleine Anfrage im Bundestag wegen der Wiederzulassung von Kunstrum und Kunstarrak. Branntweinwirtschaft 100 (1960) 522.
Small request in the Bundestag for the re-admission of Kunstrum and Kunstarrak

Labat P. Nieuwe Reizen naar de Franse Eilanden van America. Amsterdam : B. Lakeman, 1725. Part II (Tweede Deel), 4o4 p.
New Travel to the French Islands of America

Lasserre G. La Guadeloupe. Thèse U.F.I. Bordeaux 1961, 2 tomes

Le Rumeur G. Enchantement des Antilles-Connaissances des îles. Société d’éditions modernes illustrées, 1963, 343 p.
Enchantment of the West Indies-Knowledge of the Islands

Lebbin. Ein neuer Weg zur Beurteilung von Rum und Arrak. Chem. Ztg. 5o (1926), p. 334.
A new way to judge rum and Arrak

Lieber. Rectificateur adapté à un appareil distillatoire pour la fabrication des rhums, Brit. Pat., French Pat. 41 o55 (1858) ; Catalogue 1859, p. 143.
Rectifier adapted to a distillatory apparatus for making rums

Lorck-Schierning. Kleines Rum-Compendium, Alkoholindustrie 64 (1951), 18ვ-185, 221-224.

Luckow C. Was verstehe man unter der « Esterzahl » beim Original-Rum, Mitt. ATL 2o (1930), no 1, p. 28-29, 31 (1941), no 2, p. 5.
What is meant by the “ester number” of the original rum?

Luckow C. Über die Begutachtung von Rum, Arrak und Kirschwasser mit Hilfe der Ausgiebigkeitsprobe, Brennerei-Ztg. 50 (1933), 86-87.
On the evaluation of rum, arrack and kirsch with the help of the exhaustive test

Malignac G. La consommation moyenne d’alcool pur diminue. Economie et statistique, Bulletin de l’INSEE, no 22, avril 1971, p. 49-51.
Average consumption of pure alcohol decreases

Marbeau P. Le régime des alcools d’industrie et des alcools de bouche en France. Librairie Louis Arnette, 1932, 341 p.
The industrial alcohol and beverage alcohol in France

Marillier Ch. Distillerie agricole et industrielle-levurerie, sous-produits. Nouvelle Encyclopédie Agricole J. B. Baillière et Fils 1951, 632 p.
Agricultural and industrial distillery-yeast, by-products

Mariotti F. Rapport du Commerce d’importation et d’exportation des rhums, présenté par F. Mariotti, 12 p. dactylographiées.
Report of the Import and Export Trade of Rums, presented by F. Mariotti

Miot P. Le régime économique de l’alcool, Berger-Levrault 1961, 267 p.
The economic regime of alcohol

Micko K. Über die Untersuchung des Jamaika-und Kunstrums und zur Kenntnis des typischen Riechstoffes des Jamaika-Rums, Z. Unters. Nahr. Genussm. 8 (1908), p. 433-451.
On the study of Jamaica and Kunstrum and the knowledge of the typical fragrance of the Jamaican rum

Micko K. Zur Kenntnis der Untersuchung von Branntweinen (Cuba, Demerara, Jamaikarum, Arrak, Zwetschgenbranntwein, Kognak, Weingelägerbranntwein), Z. Unters. Nahr. Genussm. 19 (1910), p. 305-322.
Noted the investigation of spirits (Cuba, Demerara, Jamaikarum, Arrak, Zwetschgenbranntwein, cognac, Weingelägerbranntwein

Motschmann A. Zusammensetzung von Rum. Korrespondenz-ATL 1915.
Composition of rum

OLBRICH H. Geschichte der Melasse. Berlin 197o, 832 p. ; Chapter : RumHerstellung, p. 709-736.
History of Molasses [I already scanned it!]

OLBRICH H. Grossbritanniens Rum- und Melasse-importe im 19 Jahrhundert und deren Bedeutung für die einheimische Melassebrennerei, Branntweinwirtschaft 1o6 (1966), p. 144-149.
Britain’s rum and molasses imports in the 19th century and their importance to local molasses distillery

OLBRICH H. Zur historischen Rum- und Melassebrennerei in Deutschland. Beitrag zur Verwertungsgeschichte der Rohrmelasse vom 17. bis 19. Jahrhundert, Branntweinwirtschaft 1o5 (1965), p. 197-2o2.
To the historical rum and molasses distillery in Germany. Contribution to the exploitation history of Rohrmelasse from the 17th to the 19th century

OLBRICH H. Woher stammt das Wort Rum? Branntweinwirtschaft 101 (1961), p. 146.
Where does the word rum come from?

OLBRICH H. Über die Rum-Gewinnung aus Rohr-und Rübenmelasse, Destillateur-Lehrling II (I96I), p. 39-47, 49-51 (Supplement to Branntweinwirtschaft) ; rev. : Z. Zuckerind. 13 (1963), p. 3oo.
About rum extraction from cane and beet molasses

OLBRICH H. Über die Arrak-Gewinnung aus Rohrmelasse, DestillateurLehrling II (1961), p. 57-62 (Supplement to Branntweinwirtschaft) ; rev. : Z. Zuckerind. 13 (1963), p. 236.
About the arrack extraction from molasses

PAIRAULT M. E. A. Le rhum et sa fabrication. Collection des grandes cultures coloniales, Gauthier-Villars 1903, 292 p. fig.
Rum and its manufacture. Collection of Great Colonial Cultures

Pistorius L. J. A. Die Fabrication des Rums in zwei Anweisungen einfach, fasslich und vorteilhaft darstellt. Nebst einem vorzüglichen Verfahren, aus fuselhaftem Branntwein Franzbranntwein oder Cognac zu bereiten. Leipzig: Ernst’sche Buchhandlung; without year. 127 p. ; Review in: Balling’s Zeitschrift des Gewerbewesens 6 (1846/II), p. 678-679.
The fabrication of the rum in two instructions represents simple, comprehensible and advantageous. In addition to an excellent procedure, from fruity brandy to prepare Franzbranntwein or cognac. Leipzig: Ernst’s bookstore

Pott H. H., Nfgr. Rumhandelshaus. Wie Flensburg zur Rumstadt wurde. Eine historische Skizze, herausgegeben anlässlich des Deutschen Schulgeographentages 1964, Flensburg, 1964, 4 p.
How Flensburg became Rumstadt. A historical sketch, published on the occasion of the German School Geography Day

Pott H. H. Nfgr. Rumhandelshaus (Flensburg) : Rum : Sonne der glücklichen Inseln. 1969. 128 p.

Pott. Das Buch vom guten Pott. Eine Rum-Fibel. 2nd Edition, Flensburg (without year), 1o8 p.
The book of the good pot. A rum primer

Pott-Kompass (Journal for Employees of H. H. PoTT, Nfgr. Rumhandelshaus Flensburg) 1967, no 1-5; 1968, no 1-5; 1969, no 1-5; 197o, no 1-5; 1971, no 1-5; not published anymore.

Pouquet J. Les Antilles Françaises. Collection Que sais-je, Presses Universitaires de France, 1971, 126 p.
French West Indies. Collection What do I know

Praktikus. Dextrinausflockung im Rum-Verschnitt. Alkohol-Industrie 64 (1951), no 18, p. 488.
Dextrin flocculation in the rum blend

Ripert F. Essai de synthèse sur le rhum français, Union syndicale des producteurs de sucre et de rhum de l’île de la Réunion (336, rue Saint-Honoré ; Paris 1er), avril 1959, 84 p. dactylographiées.
Synthesis essay on French rum

Ripert F. Le sucre et le rhum à l’île Bourbon, La Revue Française septembre 1971, p. 34-35.
Sugar and rum at Bourbon Island

Rose L. Die Alkohol- und Rumfabrikation in Costa Rica, Z. Spiritusind. 51 (1928), p. 194-195.
The alcohol and rum production in Costa Rica

SAITO K. Notiz über die Melasse-Rumgärung auf den Bonininseln, Zentr. Bact. parasit. ZI (19o8), p. 675-677 ; Oester. -Ung. Z. ZuckInd. Landw. NF 37 (1908), p. 918.
Note about the molasses rum fermentation on the Bonin Islands

Schad. G. F. C. Des Pater Labats, aus dem Orden der Prediger Mönche, Abhandlung vom Zucker… , Nürnberg : G. N. Raspe, 1785, 400 + 48 p. ; (Chapter 26 : Von dem Brandteweine, der aus den Zuckerrohren verfertigt wird, und dessen Zubereitung, p. 332-338) ; further : p. 344-345.
Father Labat, from the order of preacher monks, treatise on sugar …
From brandy made from sugar cane and its preparation

Scherer A. La Réunion. Notes et études documentaires, la Documentation Française, 1967, no 33-58, 6o p.
Notes and documentary studies, French Documentation

Sedeis. Le rhum et le sucre dans les territoires français d’Outre-Mer, Société d’Études et de Documentation Économiques, Industrielles et Sociales, 1949, 101 p.
Rum and sugar in French overseas territories, Society of Studies and Economic, Industrial and Social Documentation

Schaffer E. Geruchsprüfung von Rum, Chem. Ztg. 44 (1923), p. 934.
Odor test of rum

SELL E. . Üeber Cognak, Rum und Arak. Arbeiten aus dem Kaiserlichen gusundheitsamte (a) 6 (1890), p. 335-352 ; (b) 7 (1891), p. 210-252 ; (c) Sonderdruck;
About cognac, rum and arak. Work from the Imperial Health Department

a) Üeber Cognac, das Material zu seiner Herstellung, seine Bereitung und nachherige Behandlung unter Berücksichtigung der im Handel üblichen Gebäuche, sowie seiner Ersatzmittel und Nachahmungen;
About cognac, the material for its production, its preparation and subsequent treatment, taking into account the customary commercial products, as well as its substitutes and imitations

b) Üeber, Rum, das Material zu seiner Herstellung, seine Bereitung und nachherige Behandlung unter Berücksichtigung der im Handel üblichen Gebräuche sowie seiner Ersatzmittel und Nachahmungen;
Over, rum, the material for its manufacture, its preparation and subsequent treatment, taking into account the customary commercial practices and its substitutes and imitations;

c) Separate paper (a + b): Berlin: Springer, 1891

Simon A. Untersuchungen über die Einteilung der Rume von Martinique nach ihrem Verunreinigungskoeffizienten, Oesterr. Ung. Z. Zuckerind. Landw. NF 39 (1910), p. 600-601.
Studies on the classification of Martinique’s rums according to their contamination coefficient

Stretton G. W. P. Induced fermentation in rum production , Int. Sug. Journ. 52 (1950), p. 308-309.

STEINBRINKER H. Bekenntnisse eines Rumschmugglers, Hamburg, 1924
Confessions of a Rum smuggler

Strunk H. Über Rumuntersuchungen, Veröffentlichungen aus dem Gebiete des Militar-stanitatswesens. Heft 52: Arbeiten aus den hygienischchemischen Untersuchungsstellen. V. Teil, Beriin : A. Hirschwald, 1912, p. 26-36.
About Rumuntersuchungen, publications from the field of military stanitatswesens. Issue 52: Work from the hygienic test sites

Teulieres A. L’Outre-Mer Français hier, aujourd’hui, demain. Berger Levrault 1970, 483 P.
French Overseas yesterday, today, tomorrow

WALTER E. Die Grogprobe, ein Hilfsmittel zur Beurteilung von Rum und Arrak, Alkohol-Industrie (1953), no 7, P. 165.
The grog sample, a tool for evaluating rum and arrack

Winkelhausen W. Verfahren zur Vorbereitung von Zuckerlosungen beliebiger Herkunft zur Herstellung einer Maische fur Rum-oder Arrakdestillate. Deutsche Zuckerindustrie 67 (1942), p. 47
Process for preparing sugar blends of any origin for making a mash for rum or arrak distillates

Winkelhausen W. (Holtinghausen i. Oldenburg): Verfahren zur Vorbereitung von Zuckerlosungen beliebiger Herkunft zur Herstellung einer Maische fur Rum-odor Arrackdestillate, Pat. Anm. 106654 am 12.9.1939 Protektorat Bohmen u. Mahren; D. Zuckerhind. 67 (1942) p. 47; DRP 720008 (Kl. 6b, Gr. 1.02) from 13.12.1939.

Wollny G. Martinique-Rum [aus Zuckerrohrsaft und/oder Rohrmelasse], Alkohol-Industrie 77 (1964), no 2, p. 47-49.
Martinique rum from sugar cane juice and / or molasses

Wrede F. Die Rumbrennerei in Übersee und in Deutschland, Z. Spiritusind. 51 (1928), p. 150.
The Rum distilleries overseas and in Germany

Wüstenfeld H., Luckow C. Zur Frage der Begutachtung von Auslandsrum und  Arrak, Korrespondenz ATL (Abteilung Trinkbranntwein und Likörfabrikation im Institut für Gärungsgewerbe Berlin) 18 (1928), p. 23-25.
On the question of the assessment of foreign rum and Arrak

Wüstenfeld H. Luckow C. Esterzahl, Ausgiebigkeit und Qualitat von rum und Arrak sorten des Handels, Mitt. der ATL 20 (1930), no 1, p. 2-6.
Ester number, abundance and quality of rum and arrak types of trade

Wüstenfeld H., Haeseler G. Trinkbranntweine und likore. 4th edition Berlin, Hamburg : P. Parey, 1964, p. 623 ; Chapter : Rum p. 69-78
Drinking liquors and liqueurs

Lost rum of the Japanese Bonin islands. 1908

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This was translated from German as part of operation #RumBabelFish

Note about the molasses rum fermentation on the Bonin Islands (Japan).
By K. Saito, Tokio.

The inhabitants of the Bonin Islands prepare an alcoholic beverage from cane sugar molasses, of which they produce about 300 koku [1 koku = 180.39 L] per year.

To make this beverage, pour the moderately diluted molasses into barrels that are left to stand still in a warm room. As soon as the fermentation begins after a few days, a white foam cap is created. It gradually becomes larger and denser, until finally, at the end of the fermentation, the whole surface of the liquid is covered with foam. The fermented mass is then distilled. This gives clear, colorless rum of a somewhat acidic taste, the composition of which, according to my own experiment, is characterized by the following analytical findings, namely:

Specific Gravity (at 15° C)                        0.95429
Alkohol (Volume %)                                  38.537
Acid (as acetic acid)                                   0.174 %.
Acetic acid reaction                                   clearly
Furfurol reaction                                        clearly
Fusel oil                                                          trace

In the molasses I found a copious amount of a yeast species. which was isolated from it. The investigations of this yeast carried out by me have given the following results:

The yeast forms on Kojidekokt [koji decoction?] or wort at 30 ° C a delicate, dry, white Kahmhaut [film yeast], which sinks easily to the ground. The cells are not variable in shape, usually round or oval, occasionally containing one or more vacuoles, 6-10 μ in diameter. Not infrequently, sausage-shaped cells also occur (FIG. 1). Giant colony on beer wort gelatin shows an uneven and dry surface of floury-white color. The development apparently takes place with preference in higher temperatures; in beer wort z. For example, the maximum temperature is 38 ° C, the minimum is 10 ° C, while 30 ° C is the most desirable for growth.

The spores form at least 18 to 30 ° C, but the time of sporulation is not sufficiently determined at a number of different temperatures. The skin on beer wort or Kojid kokt contains an ample amount of Asken. The spores are usually round, sometimes a little compressed or flattened. Its diameter is 2.5-3 μ. 1-4 spores develop in one cell, usually 2-3, and germinate by ordinary budding (Figure 2).

Fig. L. Cells from young skins. (X 900.)
Fig. 2. Sporulation and germination. (X 900.)

4.8 Vol. Alcohol [the fermented mash contained 2.4% alcohol] formed in the Kojidekokt (15 ° Balling) after 7 days at 30 ° C; Sown in wort, but only traces of fermentation appeared. In both cases, the yeast develops on the surface of the liquid and sinks slightly to the bottom.

In fermentation experiments in a hollow slide, the yeast fermented only dextrose and fructose, while fermentation did not occur in nutrient solution containing cane sugar, without any indication of the formation of reducing sugars. Skin formation appeared abundantly.

This yeast still grows at an alcohol content of 20 vol. in the Kojidekokt. Exuberant skin formation occurs even in such a concentrated nutrient solution) as 50 percent glucose.

It is clear from the above descriptions that we have here a yeast which must be reckoned to the genus Pichia. Most likely is Pichia californica (Seifert) Klöcker, which was first found in California red wine; but the above-mentioned descriptions are not crucial, because the spore curve in my Hefeart [yeast species?] not yet established.

Since this yeast is only able to ferment dextrose and fructose, it is easy to understand that the alcohol formation in the cane molasses takes place only at the expense of the invert sugar contained therein. My yeast is the causative agent of alcoholic fermentation in molasses, but it does not necessarily have to be active or present as long as rum preparation is dependent on spontaneous fermentation.

Botanisches Institut, Tokio, Mai 1908.

 

The Formic Acid Component of the Volatile Acidity of Rums

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Jouret C., Pace E., Parfait A. 1990a. L’acide formique composant de l’acidité volatile des rhums. Industries alimentaires et Agricoles 107, 1239 – 1241.

The formic acid component of the volatile acidity of rums
By JOURET C. *, PACE E. *, PARFAITA.**
*INRA – Station expérimentale d’Œnologie de Pech Rouge, Gruissan
**INRA – Antilles Guyanne – Pointe à Pitre Cedex

Summary

The dosage of formic acid was carried out on rums of diverse types (agricultural, molasses, large aroma), aged or not in oak barrels using a specific enzymatic method.

The rates recorded vary according to the origin of the samples and show the influence of several factors: the role of microorganisms and that of the wood of the preservation containers appear to be of importance.

Introduction

Formic acid is the first acid in the series of fatty acids that make up the Volatile acidity of rums. In the legislative concept of volatile acidity are all the organic acids, in the free state or in the salified state, drivable by water vapor [volatile by steam distillation]; lactic, succinic and sorbic acids, as well as carbon dioxide and sulfur dioxide, are not taken into account in this measure.

Various authors (MAUREL A. et al., 1965; PARFAIT A. and SABINE, 1975) have studied the global volatile acidity of rums, FAHRASMANE L. et al. (1983) and NYKAINEN L and SUOMALAINEN H. (1983) presented quantitative data for various Volatile acids found in sugarcane alcohols. In addition, LEHTONEN H.J. and SUOMALAINEN H. (1977) have demonstrated the presence of a particular volatile acid in rums: 2 ethyl 3 methyl butyric acid.

However, published results on the levels of formic acid in these alcoholic beverages are rare (KERVEGANT D. 1946, TER HEIDE R. 1986) and it therefore seemed interesting to dose this volatile acid in the different types of rums existing on the market to have a better knowledge of the chemical composition of these eaux-de-vie.

Analysis technique

We have chosen for its specificity and simplicity, the enzymatic assay technique proposed by the company Boehringer-Mannheim.

The principle of the assay is based on the oxidation of formic acid quantitatively to carbon dioxide, in the presence of formate dehydrogenase (FHD) by nicotinamide adenine dinucleotide (NAD).

The amount of NADH formed is stoichiometric with respect to the oxidation of formic acid. NADH is measured by increasing the absorbance of the medium at 365 nm.

Formic acid level of rums (in mg/l of rum at 50° GL)

We followed the dosing method indicated by the supplier of the Analytical Certificate with some slight modifications to adapt it to the problems of the brandies: on the one hand, by evacuating under a vacuum to half to reduce the volume of the sample; which makes it possible to get rid of volatile substances interfering with the assay (excessive ethanal, ethyl formate, formaldehyde, etc.); on the other hand, rums aged in barrels and thus colored were diluted to half or quarter of the intensity of their coloring before the vacuum evaporation operation. This is followed by a charcoal treatment (50 mg for 5 ml) and a fine membrane filtration.

Reproductivity is 5% in the worst cases.

Results and discussion

The assays were carried out on the different types of rums from the French West Indies of well-known origin: rums made from cane juice, rums from molasses, white and aged in oak barrels, rums grand arôme (obtained from a particular fermentation medium), as well as samples from an experiment on rums wooded and stored for 3 years in spent oak barrels.

The results expressed as mg of formic acid per liter of rum at 50° GL were collated in the following table.

It can be noted, very generally, that white agricole rums are poor in formic acid: 1.3 mg/l on average; the white rums of molasses are already richer with amounts of the order of 3.5 mg/l and this increase in the formic acid content is important for rums aged in oak barrels, as well as for white grand arôme rums. There are, however, some exceptions to this finding.

These quantitative differences can be explained by the multiple pathways of the biological formation of formic acid and, of course, by the technological processes used in the elaboration of different rums.

We can, therefore, question, first of all, the richness in formic acid of the various raw materials used in the manufacture: juice of sugar cane, molasses, vinasse [dunder, stillage].

Then, the influence of the microorganisms involved in the transformation; if the yeasts produce practically no formic acid from the sugars during a normal alcoholic fermentation, on the other hand, different microorganisms can degrade the sugars or other substrates present in the fermentative medium (AHRENS I., DIZER H. 1978) to give formic acid.

During the elaboration of rums, the health status of sugar canes (effect of pre-harvest burning, the time elapsed between cutting and implementation, etc.) as well as the conditions for obtaining and preserving molasses and vinasses; the state of maintenance of the premises and equipment; the microbiological quality of the water used for the extraction of sugar or the dilution of molasses; fermentation techniques (seeding, temperature control, …) lead to considerable variations in the composition of the fermentation flora and hence to the quality of the rums (GANOU – PARFAIT B. 1984, GANOU – PARFAIT B., FAHRASMANE L. et al 1989).

Also involved are the physicochemical phenomena that occur during the more or less advanced heating of carbohydrate substances in obtaining molasses or during distillation (SUGISAWA H. 1966, COTTIER L. et al., 1989). Vinasse, used only in certain rum fabrications or for grand arôme rums, is a bottoms product and, consequently, is richer in polar compounds, especially organic acids.

Finally, during the storage in barrels, several physicochemical phenomena known for the aging of wood spirits can be taken into account; the concentration of polar components resulting from the evaporation loss of volatile compounds as well as the oxidation of alcohols to acids. These two elements must, of course, play a reduced role, given the average volume losses of 5% per year and the low level of methanol existing in the rums. The role of wood appears, a priori, more important. In fact, the barrels undergo, during their manufacture, a heating for the bending of the staves and often a burning of the inner wall. The resulting degradation of carbohydrate elements gives furfurolic components and formic acid. This path is more or less active depending on the degree of burning and the stage of use of the barrel.

Depending on the situation, several of the elements thus rapidly defined may be added to explain the general observation and the special cases.

Thus, white agricole rums have reduced levels of formic acid because cane juice contains little. For No. 4 and No. 14 samples and to a lesser extent No. 13 and No. 10, the significant enrichment in formic acid was certainly bacterial in origin because the water required for their preparation was derived from a water table that became brackish and loaded with various microorganisms after a very dry period.

White rums from molasses contain more formic acid because the raw material used provides more for various reasons (concentration, heating, preservation). No. 4, particularly rich, is a rum having had a manufacturing accident due to bacteria present in the water. No. 14 and 15 are rums that have been rectified during distillation to reduce non-alcohol components. The degree of distilling between 92° GL and 93° GL makes it possible to eliminate, in particular, polar elements such as acids.

Apart from the grand arôme white rums whose rich formic acid is explained by their conditions of preparation (molasses with the addition of vinasse, yeast and bacterial flora complex), the rums aged in barrels are loaded with formic acid : No. 9 and No. 10 agricole rums and No. 4 molasses rum have relatively low levels as they have been kept for only 6 months in barrels and have been classified here as “Old” to facilitate the presentation of the results. The other samples have at least 3 years of wood storage, which is legally the minimum period to qualify as Old rum.

We have, moreover, a more precise idea of ​​the increase of formic acid in the rum due to the preservation in barrel with the experimentation concerning the addition of boise [wood extract]. The example, white rum, is a mixture of agricultural rum, and two rums derived from molasses, one with a low non-alcoholic coefficient, less than 100 g/hl / AP [pure alcohol], the other with a high non-alcoholic coefficient, more than 225 g/hl / AP. It contains 1.80 mg/l of formic acid. It reaches, after 3 years, a rate of 11.50 mg/l. Addition of boise at the start causes an increase in the rate to 4.40 mg/l, the two batches of boise rums reach 12.60 mg/l after 3 years of storage. The barrels used in this test had already been used for several years to try to avoid an excessive interaction of the polyphenolic compounds of the barrel compared to those of the boise.

Conclusion

In a very general way, we can say that the rate of formic acid in rums remains in the range of figures found for other eaux-de-vie, white or aged: the composition of the raw material, thermal degradation of substances carbohydrates, as well as the concentration of acids due to the evaporation of less polar volatile substances, the equilibrium formic acid / ethyl formate, the oxidation of methanol present in the initial brandy, the role of wood during barrel preservation are biochemical and physicochemical factors that play a significant role in the formic acid composition of beverage alcohol.

However, the intervention of various microorganisms, other than yeasts, can lead to a significant increase in the formic acid content of white rums. If a specific microbial activity is desired for obtaining the very strong rums, that are the rums grand arôme, other uncontrolled bacterial interventions give alcohols with defects more or less serious. The determination of the level of formic acid can then be presented as a complementary element of appreciation of the conditions for the production of a rum and the evaluation of its quality.

Bibliography

AHRENS I., DIZER H. – Zur Frage der Ameisensäurebildung durch Schimmelpilze und der Sterilität von Gärröhrchen. FLUESS. OBST, 1978, 45, 428-430.

COTTIER L., DESCOTES G., NEYRET C., NIGAY H. – Pyrolyse des sucres, analyses des vapeurs de caramels industriels, IND, AGRI. ALIM, 1989, 106,567-570.

FAHRASMANE L., PARFAIT A., JOURET C., GALZY P., PACE E. – Étude de l’acidité volatile des rhums des Antilles Françaises, IND, AGRI, ALIM, 1983, 100, 297-301.

GANOU-PARFAIT B. – Contribution à l’étude des bactéries des milieux fermentaires de rhumerie. Thèse USTL MONTPELLIER, 1984.

GANOU-PARFAIT B., FAHRASMANE L., GALZY P., PARFAIT A. – Les bactéries aérobies des milieux fermentaires à base de jus de canne à sucre. IND, AGRI, ALIM., 1989, 106, 579-585.

Ter HEIDE R. – The flavour of distilled beverages in FOODS FLAVOURS, Part B. The Flavour of beverages, ELSEVIER, 1986.

KERVEGANT D. – Rhums et eaux de vie de canne, Ed. du Golf. Varnas, 1946.

LEHTONEN M. SUOMALAINEN H. – Rum – in Economic Microbiology. AH, ROSE Ed. Woll. Alcoholic beverages, Academic Press London.

MAUREL A., SANSOULET O., GIFFARD Y. – Étude chimique et examen chromatographique en phase gazeuse des rhums, Ann, Fals. Exp, chim, 1965, 58, 29-303.

NYKAINEN L., SUOMALAINEN H. – Aroma of beer, wine and distilled alcoholic beverages. D. REIDEL Publishing Cie, 1983.

PARFAIT A., SABIN G. – Les fermentations traditionnelles de mélasse et de jus de canne aux Antilles Françaises. IND, AGRIC. ALIM, 1975,92,27-34.

SUGISAWA H. – The thermal degradation of sugars, 2/the volatile decomposition products of glucose caramel, J. Food, Sci, 1966, 31,381-385.

 

Glycerol in the alcoholic fermentation of molasses and sugar cane juice

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Parfait A., Jouret C., 1980. Le glycérol dans la fermentation alcoolique des mélasses et des jus de canne à sucre. Industries alimentaires et Agricoles 97, 721-724.

Le glycérol dans la fermentation alcoolique des mélasses et des jus de cannes à sucre
by PARFAIT A. *, JOURET C. **
with technical collaboration from G. SABIN and Madame G. MIGLIORI

(*) C.R.A.A.G. Station de Technologie, Guadeloupe.
(**) C.R.A. de Toulouse, Laboratoire de Technologie des Produits Végétaux, Auzeville.

Summary

Authors have specified the influence of various factors (mode of conduct, pH, seeding rate, sugar content, yeast species) on the amount of glycerol found in rums.

They have also shown that glycerol can serve as a carbon substrate for various bacteria and give, as a result, derivatives having a negative role on the organoleptic qualities of this eau-de-vie.


Glycerol is a secondary product formed by the metabolism of sugars during alcoholic fermentation.

Depending on the conditions, a more or less important fraction of the sugars is thus transformed into glycerol. This results in different values of the fermentation yield.

Genevois (1936) proposed an equation between various byproducts of alcoholic fermentation

2A + B + 2M + H + 5S = ε = G

A, B, M, H, S and G being respectively the molar concentrations of acetic acid, 2-3 butane diol, acetoin, acetaldehyde, succinic acid and glycerol. This equation has been the subject of much work and has been confirmed by Lafon (1955). It can be considered valid in 90% of fermentations.

Subsequently, Nordstrom (1968) and Oura (1977) showed that there was a correlation between the redox potential of the fermenting medium and the formation of glycerol.

According to Oura, the formation of succinic acid is related to the production of glycerol and has the same purpose: to balance the excess of reduced nucleotides.

Glycerol, whose physiological interest for yeast appears to be small, seems however to play a significant role in the regulation of compounds such as pyruvic and succinic acids that enter, instead, in the formation of constituents of the cell. Similarly, glycerol, via its phosphoric ester, L-α glycerophosphate, combines with activated fatty acids to give phosphatidic acid. This last body leads to lipids. This same ester allows the use of glycerol by many breeds of yeasts as a source of carbon. Although the low volatility of glycerol explains its absence in rums, it has been possible to determine various compounds from its degradation. These generally have a negative effect on the organoleptic qualities of eaux-de-vie.

Since the work of Warcollier and Le Moal (1932) on ciders and those of Serjak et al. (1954), we attribute to the action of lactic acid bacteria the appearance of acrolein in spirits.

Dubois et al. (1973) identified two acrolein derivatives in an abnormal taste rum: ethoxy-3-propanol and ethoxypropane. These compounds are not directly responsible for the unpleasant flavor of the rum studied but can serve as indicators.

Smedt and Liddle (1976) have correlated the presence of allylic alcohol (2propene 1 ol [I think that is correct nomenclature]) with some bad tastes in various types of spirits. They also showed a relationship between the contents of this alcohol and those of ethoxypropane.

Thus, the glycerol which is at the origin of acrolein (and products derived from this aldehyde) following metabolic pathways not completely elucidated, can therefore be degraded in fermenting media based on cane juice and molasses.

Given these biochemical and technological considerations, it seemed interesting to specify some parameters of the production of glycerol in the fermentation of the basic products of the different types of rums.

Experimental Protocol

Glycerol was determined according to the enzymatic technique of Eggstein and Kuhlmann (1974) after defecation of natural media with lead acetate.

Samples of fermented media were taken from industrial plants previously described by Sabin and Parfait (1975). Just remember that the following raw materials cane juice, syrup and molasses, are used respectively for the development of agricultural rums, syrup and industrial.

The results are reported in Table 1.

Table 1.
Glycerol content expressed in g / l in fermentation media of different types of rums

399/5000
Following these measurements, tests were conducted in the laboratory to specify the glycerol formation conditions according to the pH, the fermentable substrate concentration, the yeast seeding rate, the species and the yeast strains.

The growing conditions were as follows:
—Molasses: 300 g / l,
—seeding rate: 1 g /,
—fermentation temperature: 30 ° C.

The seeding was carried out using yeast creams in order to eliminate the glycerol fraction that could be brought by the starter.

The yeast strain saccharomycès cerevisiae used is the No. 493 of our collection, isolated from a natural fermentative medium of agricultural rum.

Influence of pH:
Initial pHs were set at 3.5 – 4.0 – 4.5 – 5.0 – 5.3.

The evolution of the glycerol level during the fermentation was regularly monitored.

For example, for the medium at pH 40, the following figures were noted:

These figures vary very little according to the different pHs tested.

Influence of molasses richness:

The molasses concentrations of 150 g/L, 200 g/L, 250 g/L and 300 g/L were varied, the seeding rate was 1 g/L, the fermentation temperature 30° C and the initial pH set to 5.

The glycerol levels found were in order: 1.5 g/L, 1.7 g/L, 2.3 g/L and 2.5 g/L. They follow the same progression as that of sugars.

Influence of seeding rate:

By changing the seeding rate from 0.25 g/L, 0.50 g/L, 1.0 g/L, 2.7 g/L and 2.5 g/L, 4.0 g/L, 5.0 g/L in a medium similar to the previous one, does not find a statistically valid variation in the final glycerol contents.

Influence of yeast species isolated from natural fermentation media: Hansenula anomala, Saccharomyces cerevisiae, Saccharomyces aceti, Schizzosaccharomyces pombe.

Only these last yeasts have glycerol production curves very different from those of the other yeasts tested.

Influence of the mode of conduct of industrial fermentations:

By examining the manufacturing process generally followed in the industrial production of rum, we realized that glycerol appears during the aerobic growth phase of yeasts. Given the reduced richness of the medium, often less than 200 g/L of molasses or about 100 g/L of fermentable sugars, and the low rate of seeding practiced, it can be said that currently in the French West Indies, a part not negligible sugar is consumed to develop glycerol.

On the other hand, the operation of industrial installations is discontinuous. The canes brought to the distillery may be subject to pre-fermentation, with consequent production of glycerol. The glycerol level reaches 0.8 g/L on average in pipes that are poorly emptied.

Glycerol derivatives

Yeasts and bacteria can use glycerol. For these latter microorganisms, a review was conducted by Lin (1976).

Ganou and Parfait (1980) determined many species of bacteria in the flora of fermentation media leading to the various qualities of rums. As can be seen from Table II, cane juice and molasses, even when preserved, contain few germs. From the first hours of fermentation, a flora of varied origin (installations, water, environment) develops. During the course of fermentation, anaerobiosis causes a reduction in the number of species present in the medium. Lactic acid bacteria and Clostridia are mainly found. Acetobacters may appear at the end of fermentation and degrade the ethanol formed.

If sometimes the intervention is beneficial (some strains of clostridia, among others, for the production of rum aroma) most often it is detrimental to the organoleptic qualities. Acetobacters cause, for example, a detrimental increase in the level of acetic acid and ethyl acetate.

The appearance of volatile derivatives of glycerol is due, for a large part, to the activity of lactic acid bacteria, as we have observed in some distilleries. We searched in the lab, among the species of lactic acid bacteria that we had isolated, those that degraded glycerol. The tests were done aerobically and anaerobically.

Three culture media were used: M1, M2, M3.

TABLE 2

The kinds of bacteria found in fermentative environments. (+) = present, (-) = absent. The number of signs indicates the frequency. A, B and C represent the environments leading to agricultural rum, molasses rum and rum grand arôme

Under the conditions of our tests, some lactic acid bacteria use glycerol as a carbon source. Surely we could identify among them strains of leuconestoc mesenteroid. Other species also having a metabolic activity from glycerol are being identified.

Acrolein and 2propene ol 1 were found among the products formed by gas chromatography using a Tracor 560 with flame ionization detectors. The phase for the 50 foot Scotch column and 0.2 inch diameter used is carbowax 1540; the flow rate of nitrogen, carrier gas, is 3 ml/min. Temperature programming was carried out: 6 minutes at 58° C. and then an increase of 8°C. per minute up to 120°C.

The injection of 1 μL of rum can detect 1 ppm acrolein or 2propene ol 1.

A typical chromatogram is given in Figure 1.

Conclusions

In the production of rum, glycerol may be found in greater or lesser quantities depending on the mode of conduct of fermentation operations.

If the raw material (fresh juice or molasses) has not been the subject of microbial activity, in particular by yeasts, the glycerol contents will be very low.

The use of a leavening tank causes a significant concentration of glycerol from the beginning of the anaerobic phase. Schizzosaccharomyces cause the appearance of significant amounts of glycerol, which can cause problems when there is a risk of contamination by bacteria degrading this substance.

Indeed, lactic acid bacteria (leuconostoc mesenteroid type) can metabolize glycerol to lead in particular to acrolein and 2propene ol 1 found in rums with other products of negative organoleptic character.

These observations should guide the process of fermentation of raw materials to obtain a good quality rum.

BIBLIOGRAPHY

DUBOIS P., PARFAIT A., DE KIMPE J. (Mme), 1973. – Présence de dérivés de l’acroléine dans un rhum à goût anormal. Ann. Technol. Agric., 22, 131-135.

EGGSTEIN M., KUHLMANN E., 1974. – In methods of enzymatic analysis (Bergmeyer H.L.), Vol. 4, 1825-1835, « Verlag Chemie Weinheim ».

GANOU B. (Mme), PARFAIT A., 1980. – Les microorganismes de fermentation de mélasse et de jus de canne (en préparation).

LAFON M. (Mme), 1955. – Contribution à l’étude de la formation des produits secondaires de la fermentation alcoolique. Thèse de Docteur en sciences physiques, Bordeaux, Ann. Techn. Agri., 198 p.

LIN E.C., 1976, – Catabolisme du glycérol et sa régulation chez certaines bactéries. Annal Review of microbiology, vol. 30.

NORDSTROM K., 1968. – Yeast growth and glycerol formation II carbon and redox balances. J. Inst. of brewing, 74, 429.432.

OURA. E., 1977. – Reaction products of yeasts fermentations. Process Biochemistry, 12, 19-35.

SABIN G., PARFAIT A., 1975. — Les fermentations traditionnelles de mélasse et de jus de canne aux Antilles Françaises, lnd. Agric. Alim., 92, 27-34.

SER JAK W.C., DAY W.H., VANLANEN J. M., BORUFF C.S., 1954. – Acrolein production by bacteria found in distillary grain mashes, Applied Microbiology, 2, 14-20.

DE SMEDT P., LIDDLE P.A.P., 1976. – Présence d’alcool allylique (2propène  ol 1) et dérivés dans les eaux-de-vie. Ind. Alim. Agric., 93, .41-43.

WARCOLLIER G., LE MOAL. A., 1932. – Présence accidentelle d’acroléine dans l’eau-de-vie de cidre. C.R. Acad. Science, 194, 394.

Ethyl Esters Of Higher Fatty Acids Of Rhums

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Parfait A., Namory M., Dubois P., 1972. Les esters éthyliques des acides gras supérieurs des rhums. Annales de Technologie Agricoles 21, 2, 199–210.

ETHYL ESTERS OF HIGHER FATTY ACIDS OF RHUMS

A. PARFAIT, M. NAMORY and P. DUBOIS *

Station de Technologie végétale, I. N. R. A.,
Petit-Bourg (Guadeloupe)
*Station de Technologic des Produite vegetaux, I. N. R. A.,
21034 Dijon Cedes

Summary

Rums of good quality, especially in ethyl esters, generally have high fatty acids with a high content of volatile esters, and particularly of ethyl esters of higher fatty acids (from C8 to C16). These esters are by-products of alcoholic fermentation, such as higher alcohols, and behave like them during continuous distillation.

The levels of ethyl esters of the higher fatty acids are higher when the distillation is done on the lees, when cane wax is added to the must before fermentation and by selection of a species, or even of a strain, of yeast.

The ethyl ester contents of the distillate fatty acids were three times higher with Saccharomyces cerevisiae S. 132 than with Saccharomyces cerevisiae Berlin II. The highest content was obtained with a strain of Schizosaccharomyces Pombe yeast from the sugar cane regions.

It has not been possible to establish definitively a correlation between the fatty acid composition of the lipids of the yeast cell and the ethyl esters produced.

Key words: rums, ethyl esters, higher fatty acids, distillation.

I- INTRODUCTION

The eaux-de-vie can be considered as hydroalcoholic solutions of a “non alcohol” which characterizes them and that the chemical analysis makes it possible to separate in dry extract, acids, aldehydes, esters and higher alcohols, These analyzes can be completed by olfactory observations on isolated fractions by distillation. Finally, much finer separations can be obtained by gas chromatography for the determination of volatile constituents and by other chromatographic methods for the study of nonvolatile compounds.

In the case of rums, there may be a relationship between their quality and their ester content (KERVEGANT, 1946) and, in spite of many exceptions, it seems that high ester levels characterize the most aromatic rums. Observations made after fractional distillation even suggest that heavy esters have the greatest influence on the aroma of these eaux-de-vie, as is the case with whiskeys (SALO et al., 1972). The technology of rums should therefore be able to take advantage of recent studies on the formation of esters by yeasts during the fermentation of wines and beers.

A.—Mechanism for the formation of esters

PEYNAUD (1956) has shown that the levels of ethyl acetate in fermented media depend on the yeast species, and that they are always higher than those predicted by the calculation from chemical equilibrium reactions.

According to NORDSTRÖM (1964), the esters are formed by alcoholysis of the acyl-coenzymes A according to the reaction

and their formation depends on the contents of acyl-Co A and alcohols (RAINBOW, 1970) The alcohols react all the better as they are primary, with a linear chain and of lower molecular weight. Since ethyl alcohol is the most abundant, the esters formed are mainly ethyl esters.
On their side, acyl-Co A have three modes of formation.

Activation of fatty acids in the presence of ATP.

In view of the very small quantities of free fatty acids in fermented media, it seems that this reaction can play only a minor role.

Oxidative decarboxylation of α-cetanol acids.

This reaction is thought to be responsible for most of the acetyl-Co A, by oxidative decarboxylation of pyruvic acid. The other α-keto acids, that is to say certain intermediates of the metabolism of sugars and of amino acids, are present in much smaller quantities than pyruvic acid, and very few esters of the corresponding acids are formed. (propionic, isobutyric, methyl-2 and 3-methyl-butyric).

Reaction between an acyt-Co A and malonyl-Co A.

This reaction, which leads to the formation of the fatty acids of the lipids of constitution of the yeast, is also at the origin of the ethyl esters of linear fatty acids with an even number of carbon atoms.

Ester formation is related to yeast growth, as is that of higher alcohols and the formation of higher fatty acid esters is more particularly related to lipid metabolism.

It is therefore, like that of lipids, favored by the presence of pantothenic acid, as constituent of coenzyme A, and of the biotin which participates in the carboxylation of acetyl-Co A in malonyl-Co A, and which therefore, competes with the formation of ethyl acetate.

Factors that limit the development of yeasts have an inhibitory role. This is particularly the case of linear fatty acids having 6 to 10 carbon atoms which are toxic to yeasts.

B.— Fermentations in rhummeries

We know imperfectly the flora that develops in the environments put in fermentation to produce the different types of rums. HARRISSON and GRAHAM (1970) point out, in a development, that the budding yeasts gradually replaced, in Jamaica, a fission yeast, Schizosaccharomyces melacei, which was dominant at the beginning of the century.

Overall, fission yeasts are preferable to budding yeasts, in part because they promote the development of butyric bacteria (Clostridium saccharobulyricum, in particular) that produce very large quantities of esters. These fission yeasts are particularly abundant in the flora used for the elaboration of “grand arôme” rums.

It is also possible that yeasts of the genus Torulopsis play an important role in the formation of esters from sugars.

In the French Antilles, Saccharomyces cerevisiae is the main agent of fermentations. Other yeasts are present, including Pichia, Hansenula, Candida and Schizosaccharomyces. Their role is difficult to assess in practice.

C.— Role of distillation

Esters are poorly soluble in water and behave like head products in low alcohol environments. They behave, at the same time, as bottoms in the distillation columns when the alcoholic degree reaches values ​​of the order of 50 to 60 ° GL. Only ethyl acetate is always in the heads. Butyrate and ethyl hexanoate distill substantially at the same time as ethanol. The ethyl esters of acids that have 8 carbon atoms and more distillate after ethanol and it is these acids that we consider here as superior.

The contents of the rums in the ethyl esters of the higher fatty acids are therefore related to the alcoholic degrees to which they are distilled in the columns. The higher this degree, the poorer the rum obtained in these esters. It is interesting to note that the behavior of higher alcohols is quite similar to that of heavy esters.

In any case, the analytical results obtained on rums, and in particular the quantitative results obtained by LIEBICH et al. (1970) (Table I) shows that the main esters are the ethyl esters of fatty acids number by carbon atoms. Ethyl acetate and butyrate dominate among the light esters, caprate and palmitate among the heavy esters. Certain unsaturated acid esters are also present, but in smaller proportions.

Table I
Ethyl esters reported in rums

After having measured the ethyl esters of higher fatty acids in commercial rums, various factors have been studied that may affect the levels of these constituents in rums: presence of yeasts during the distillation fermentation in the presence of cane wax fermentation by various species of yeast. These different points were completed by the analysis of lipids of yeast constitution.

II- MATERIAL AND METHODS

A.— Culture media

Two media were used, one is based on cane molasses, the other synthetic.

These solutions are brought to pH = 5 with sulfuric acid and sterilized by treatment at 110 ° C. for 35 minutes.

B.— Yeast uses

Apart from Schizosaccharomyces pombe, which was isolated from a fermentation of cane juice medium, the other species came from the Dijon Plant Products Technology Station collection: Saccharomyces cerevisiae strains Berlin II and S. 132, Pichia membranaefaciene, Hansenula anomala and Candida krusei. These yeasts are those which have been reported as participating in the fermentation of musts in rhummeries.

With a young culture of yeasts, flasks containing 100 ml of liquid Wickerham medium are inoculated with malt. After about 24 hours at 28 ° C, in stirred medium, the yeasts are collected by centrifugation, then they are rinsed twice with saline water. All media are inoculated so that they initially contain 5 · 10 ^ 6 yeasts per ml. A magnetic bar agitates the first day and fermentation lasts 3 to 4 days at 28 ° C.

C.— Analysis made on distillates

The apparatus to be distilled is made of glass and includes a balloon, an electric heater, a column of Vigreux of 50 cm of height and a refrigerant.

Ethyl esters of fatty acids of 8 to 16 carbon atoms are not very polar and their most selective solvent must itself be polar. We chose pentane.

A test portion of 100 ml of distillate at 50 ° GL is stirred vigorously with 50 ml of pentane. The addition of 100 ml of water causes an immediate demixtion without emulsion formation. The organic phase is dried over anhydrous sodium sulphate and brought to a tenth of a milliliter by distillation. Two microliters are injected into a Perkin-Elmer model 880 chromatograph under the following conditions: column filled with Chromosorb G 80/100 mesh impregnated with OV 17 at 5 p. 100, length 4 meters, diameter 3 mm. Nitrogen flow 25 ml / min. Temperature program of the injection from 160 to 240 ° C at 2 ° C per minute. Since the rums contain only traces of ethyl pelargonate, this analysis is made quantitative by the addition of one milliliter of an alcoholic solution of this ester at 1 mg / ml to the 100 ml of distillate used. Previous tests performed on synthetic solutions showed that the relative errors were less than 5 percent. The exact nature of the esters was verified in the chromatographic conditions, but in coupling with a Varian *** type CH 5 mass spectrometer (250° C source, 70 eV electron energy). All these ethyl esters are characterized by a rearrangement peak for m / e = 88,

and by their molecular peaks. Mass spectrometry also makes it possible to observe the absence of important interferences.

D.— Analyses faitee sur les levures

After fermentation, the yeasts are separated by centrifugation (10,000 g). They are twice washed with physiological water, and then harvested at the bottom of the tubes using a spatula. At weighing of the wet mass, the dry matter content is determined on an aliquot part. [aliquot was a guess. The scanning is cutting off the edge for this page].

The total lipids of the yeasts are determined by the method of KAHANE and ROUS (1961) and then saponified by the alcoholic potash. Unsaponifiable matter is extracted with petroleum ether. After acidification, the fatty acids are extracted with the same solvent, then they are esterified with hydrochloric methanol and analyzed by gas chromatography on an impregnated column [guess] of diethylene glycol succinate (impregnation rate 15%). 3 meters, inside diameter 3 mm, Chromosorb G 80/1000 mesh, temperature 190 ° C.

E.— Autres dosages

The yeasts are counted with a cell count on a possible dilution of the medium. The reducing sugars are dosed, after acid hydrolysis, by the method of Bertrand. Finally, the volatile acids are determined after entrainment by steam. [I think I translated that last part correctly.]

III. — RESULTS

A.— Levels of ethyl esters of the higher fatty acids of commercial rums

The contents of these esters of five rums were compared: two agricultural rums obtained from cane juice in a traditional factory where fermentations are most often spontaneous, and three rums obtained from industrial rum distillates at 64 ° GL, a light rum distilled at 94 ° GL, and a rum “grand arôme” distilled at 63 ° GL as industrial rum, but obtained by a fermentation procedure that uses a starter with yeasts of the genus Schizosaccharomyces and bacteria.

The results obtained are shown in Table 2.
The first three rums have very similar contents in these esters, light rum contains only traces, the most abundant being the *** of ethyl whose content is of the order of 0.05 mg / liter of pure alcohol. The numbers obtained for the rum “grand arome” are much weaker than were expected. This rum has a very low content in total esters (about 2 g / liter of pure alcohol).

Table 2

Ethyl esters of various commercial rums
(in mg per liter of pure alcohol)

B.— Role of yeasts during distillation

The synthetic medium and the molasses-based medium were used with yeast Saccharomyces cerevisiae Berlin II. In each test, four liters of medium are prepared and fermented, then they are divided into two equal parts, one of which is centrifuged before distillation to eliminate the yeasts.

The results reported in Table 3 show that distillation in the presence of yeasts leads to a significant gain in esters. These compounds are poorly soluble in low alcohol environments and are likely to be absorbed on the surface of yeasts and suspended particles.

TABLE 3

Role des levures et de la cire de canne sur les teneurs des distillats en esters ethyliques des acides gras superieure
(n-C8 n-C16 en mg par litre d’alcool pur)

C.— Role of cane wax

The wax is the richest part of the higher fatty acids of the cane (*** according to MARTIN and JUNIPER, 1970), and it was interesting to see what could be its influence.

It was added in the form of an emulsion at a dose of 0.300 g per 4 liters of medium. The results (Table 3) show that this addition of wax allows a medium based on cane molasses to double the levels of distilled ethyl esters of fatty acids with 8 and 10 carbon atoms which are among the interesting ones on the olfactory plane ( SALO et al., 1972).

The synthetic media are incompletely fermented and the results obtained are unusable.

D.- Role of the yeast species

EL SHEHATA (1960) has shown that molasses musts are fermented, in practice, by the following yeast species: Saccharomyces cerevisiae, Schizosaccharomyces pombe, Hansenula anomala. Pichia membranaefaciene and Candida krusei. The first two ferment well in anaerobic environment, the last two do not ferment sucrose.

TABLE 4

Ethyl esters of distillates obtained with different yeast species
(in mg per liter of pure alcohol)

Yeast species used:
Pichia membranacfaciens (P. m.), Hansenula anomala (H. a.), Schizosaccharomyces pombe (S. p), Candida krusei (C. k.), Saccharomyces cerevisiae S. 132 (S. c. 132).

We have fermented, under the conditions defined above, five mediums based on molasses with respectively each of the following yeasts:

– Pichia membranaefaciens (P. m.)
– Hansenula anomala (H. a.)
– Schizosaccharomyces pombe (S. p.)
– Candida krusei (C. k.)
– Saccharomyces cerevisiae S. 132 (S. c. 132).

After fermentation, the media are distilled in the presence of yeasts. The results are summarized in Table 4.

Some media have been incompletely fermented because Pichia and Candida do not ferment sucrose.

E.- Fatty acid content of yeasts

The determinations were made on yeasts derived from fermented media based on molasses similar to the preceding ones, but, to promote the multiplication of yeasts, the stirring period was increased to 48 hours instead of 24. Tables 5 and 6 report on the results obtained during various determinations.

TABLE 5

Data on the fermentation by different species of yeasts in molasses medium

TABLE 6

Comparative composition of lipids of various yeast species

There appears to be some correlation between the amount of ethyl esters of the higher fatty acids produced by these yeasts and their levels of saturated fatty acids. However, the methods used do not make it possible to know if the fatty acids doses were glycerol related in the lipids of constitution, or if they were in the form of ethyl esters and associated with the yeast walls.

IV.— DISCUSSION

The levels of ethyl esters of the higher fatty acids of commercial rums are close to those we were expecting to find except for the “grand arôme” rum. On rum of this type Liebich et al. (1970) indicate contents of the order of 170 mg per liter of pure alcohol, thus of much higher contents and which are similar to those obtained when working with Schizosaccharomyces pombe. The poorly defined origin of these products makes it possible to make only findings.

The presence of yeasts during the distillation makes it possible to obtain richer eaux-de-vie in esters. This confirms the work of GUYMON and CROWELL (1969) and partially explains the preference of practitioners for the lees distillation method.

GUYMON and CROWELL (1969) assume that, during continuous distillations, the fatty acids released by the yeasts are esterified with ethanol on the first plats of the column. The results reported here do not seem to be explained in this way since the distillations were performed, in the laboratory, discontinuously and that therefore the higher fatty acids could not be found in the free state presence of a high concentration of ethanol. It seems more probable that esters were linked to yeasts, either on their wall or in their cells and that they were released by heating.

The results concerning the addition of wax are more difficult to interpret since its composition is poorly known. It is known to contain a small amount of free fatty acids with a very high carbon number, which are yeast growth activators, but its biotin and pantothenic acid contents are not known in industrial practice. It will be interesting to know if the simple addition of palmitic acid would not have effect, palmitic acid being the main fatty acid of the lipids of yeast.

Finally, there were important differences between one yeast species and another, even from one strain to another within the same species. Under the same conditions, Saccharomyces cerevisiae Berlin II produced 36.5 mg of these esters per liter of pure alcohol (Table 3) while Saccharomyces cerevisiae S. produced 114 (Table 4).

The highest content was obtained with Schizosaccharomyces pombe, which is the dominant species in the flora of wines prepared for the production of “grand arôme” rum.

V.— CONCLUSION

Although their mixture can not be at the origin of the characteristic aroma of the rums, it seems probable that the ethyl esters of the volatile fatty acids participate in their qualities. Therefore, it was useful to specify the conditions allows rums rich in these constituents.

The most important factor is doubtless the distillation and alcoholic degree to which the alcohols are obtained continuously. The higher the rectification rate, the lower the ester and higher alcohol contents.

On the other hand, three factors seem to be able to be used to increase the levels of esters while keeping low contents of higher alcohols: the addition of wax, the distillation of the turbid substances and the selection of a species, or even of a yeast strain.

Received for publication in October 1972.

SUMMARY

ETHYL ESTERS OF THE RUM HIGHER FATTY ACIDS

Good quality rums have generally a high content of volatile esters and especially of ethyl esters of higher fatty acids (n-C8, to n-C16). These esters are secondary products of alcoholic fermentation, like higher alcohols,and behave like them during a continuous distillation process.

The quality of rums should be improved using our recent knowledges on esters production by yeasts in beer and wine.

Higher contents of ethyl esters of higher fatty acids can be obtained when the yeasts are not removed from the wines before distillation, when sugar cane wax is added to the must before fermentation and when a yeast species, and even a yeast strain, is selected.

The higher fatty acid ethyl ester contents of distillates were three times higher with Saccharomyces cerevisiae S. 132 than with Saccharomyces cerevisiae Berlin II. The highest content was obtained with a strain of Schizosaccharomyces pombe, a native yeast of sugar cane growing Countries.

A correlation between the fatty acids composition of the lipids of the yeasts cells and the ethyl esters produced could not be conclusively established.

BIBLIOGRAPHY

BARAUD J.,MAURICE A., 1963. Les alcools et esters des eaux-de-vie de canne et de pomme. Ind. aliment. agric., (1), 3-7.

EL SHEHATA A. M., 1960. Yeasts isolated from sugar cane and its juice during the production of Aguardente de Cana. Appl. Microbial., (8), 73-75.

GUYMON J. F., CROWELL E. A., 1969. Gas chromatographic determination of ethyl esters of fatty acids in brandy or wine distillates. Amer. J. Enol. Vitic., 20 (2), 76-85.

HARRISSON J. S., GRAHAM J. C. J., 1970. In The Yeasts, vol. 3, Acad. Press, London.

KAHANE E., Rous S., 1961. Nouvelle methode d’extraction des lipides, in Enzymes of lipid metabolism 82-90, Pergamon Press, Oxford.

KERVEGANT D., 1946. Rhums et eaux-de-vie de canne. Les Editions du Golfe, Vannes.

LIEBICH H. M., KOENIG W. A., BAYER E. 1970. Analysis of the flavor of rum by gas liquid chromatography and mass spectrometry. J. Chromatogr. Sci., 8 (9), 527-533.

MAARSE H., ten NOEVER DE BRAUW M. C., 1966. The analysis of volatile components of Jamaica rum. J. Food Sci., 31, 951-955.

MARTIN J. T., JUNIPER B. E, 1970. The cuticles of plants. Ed. Arnold Publishers Ltd, Edinburgh.

NORDSTRÖM K., 1964. Studies on the formation of volatile esters in fermentation with brewer’s yeast. Svensk Kemisk Tidskrft, 76 (9), 510-543.

PEYNAUD E., 1956. Sur la formation d’acetate d’ethyle par les levures du vin. Industr. aliment. agric. 73 (4), 253-256.

RAINBOW C., 1970. Brewer’s yeasts, in The yeasts, vol. 3, Acad. Press, London.

STEVENS  R., 1965. Gas chromatographic identification of ethyl ester of fatty acids in domestic and imported rums. J. Ass. off. agric. Chem., 48 (4), 802-805.

SALO P., NYKANEN L., SUOMALAINEN H., 1972. Odor thresholds and relative intensities of volatile aroma components in an artificial beverage imitating whisky. J. Food Sci., 37 (3), 394-398.

SUOMALAINEN H., PUPUTTI E., NYKANEN L., 1968. Composition of the aroma in some brands of whisky and rum analyzed by customary methods and by gas chromatography. Kemian Teollisuus 25 (5), 399-404.

Karl Micko’s Quantum Leap

Sponsor my distilling work simply by sharing the artisan workshop of the Bostonapothecary on social media. Copy, Paste, Share, Support!

This ends up being the most pivotal paper in all of spirits in the 20th century. It is not readily apparent, but everyone built upon it. No one references it so Micko’s ideas were known but somehow lost and not in anyone’s bibliographies. Arroyo brought the techniques to a whole new level. The French papers from the INRA acknowledge Micko’s central technique even though they focus on microbiology.

I propose taking it further and updating everything for a new generation of off the shelf equipment and productivity needs. I was even beginning to arrive at some of the same techniques myself in my Distiller’s Workbook series before I got clarity from Arroyo and historical clarity from Micko.

The original document is of a rough scanning that OCR hated so I had to do way too much editing. I think mistakes still live in the document, but whatevs, I’m busy. I rolled this out unannotated so people intentionally miss the significance. I may update it slowly to reveal my ideas. My lab is looking like it will cost $25,000. The techniques encompass product development and evolution for distillates from fermentations and well as a full on gin lab for botanical assay and formula development. The gin lab might actually push the price to $30k. University programs will eventually teach these techniques as the core of their curriculum and we’ll eventually get support from distillery trade organizations.

RESEARCHES ON JAMAICA AND ARTIFICIAL RUM.
By Dr. Karl Micko,
Director der Stattlichen Untersuchungaanstalt 
fur Lebensmittel in Graz.

I.—Examination of Jamaica and Artificial Rum.

Jamaica rum is of commerce, one of the most valuable and highly esteemed spirits of commerce,—a distinction which it owes to its characteristic and inimitable flavour. As it is produced in the tropics it is evident that duty and transport charges raise its original cost to a high figure on the European market. The concentrated rum, known as “original rum,” is too dear for the ordinary consumerit is therefore general for the retailing trade to break down the original rum, and by so doing the price falls in proportion to the degree of dilution effected. With many well established firms it is the usual custom to express the content of the broken spirit in degrees of the dilution and to fix the price accordingly. Generally, the original rum is broken down different dilutions for the convenience of the small dealers. It is, to however, preferable for the merchant to import the original rum and break it down himself. In this way he is able to control the dilution, and to be certain of the true content of the diluted spirit in original rummoreover, economy is thus effected, for charges for dilution and other expenses are saved.

In the case of many kinds of rum it is necessary to break down with spirit, for when in the concentrated condition their flavour is not always apparent. It is a particularity of certain rums that the fine aroma is only developed after breaking down; and this was instanced quite recently in our laboratory in the case of a sample of Jamaica rum for which a high price has been paid, but which when added to tea was stated to have a disagreeable taste. We were, however, soon convinced that this was such an example, and that the fine flavour was only hidden, for on breaking the sample down with 60 per cent. spirit the rich aroma and taste of genuine Jamaica rum was developed.

Since genuine Jamaica rum is a costly spirit. it is only to be expected that many attempts are made to imitate it. There are numerous receipts for the cheap manufacture of rum in Europe from molasses; but although it is known that the esters of formic, acetic, butyric, capric, and other acids occur in Jamaica rum, it has been impossible up to the present to make a spirit even approaching the genuine article. How far such attempts have been from successful may be judged by the fact that a rum expert has no difficulty at all in identifying an artificial rum by its flavour and aroma. There are upon the market many spirits which have been imitated much more successfully than Jamaica rum. Brandy, for example, is now imitated with such skill that the figures obtained by chemical analysis do not always indicate the fictitious article. Indeed, a brandy can be prepared to give analytical values the same as those found from a genuine sampleand brandy experts are now in no way so certain of judgment as formerly. The rum taster, on the contrary, has a much easier taskthe analyst. moreover, can not only readily differentiate the genuine from the artificial product, but is in the position to be able to detect what might easily escape the expert, namely, the admixture of even small amounts of genuine Jamaica rum with an artificial spirit.

The reply to the question as to why it has not been found possible after so many attempts to even approximately imitate the peculiarly fine aroma and taste of Jamaica rum is that it is characterized by a special flavouring constituent, which is not to be found in the best rums made in Europe, nor in the artificially made product. The flavour and aroma of potable spirits is not derived from one but from a number of different bodiesthis is true of Jamaica rum, but the basis of its characteristic flavour is an aromatic constituent which is peculiar to it alone.

This constituent can readily be separated by fractional distillation,  even when present in small amounts. If Jamaica rum is distilled, a simple tubular condenser being used, and the distillate collected in eight fractions, the first four are not in any way specific of the genuine rum. The peculiar flavouring constituent comes over mostly in the fifth and sixth fractions; towards the end of the distillation the amount of this body gradually decreases so that in the eighth fraction little or none is present. Generally most of it comes over in the sixth, but the alcohol content and method of distillation have, of course, an influence in determining the particular fraction. Concentration to a definite fraction can obviously be more readily effected by using a still-head.

Together with the flavouring constituent a characteristic body of a terpene-like odour also comes over. That terpenes occur in brandy has been pointed out by K. Windisch in his well-known work on the subject,* [*Arbeiten aus dem Kaiserl. Gesunuheitsamte, 1893, 8, 279.] and he has expressed the opinion that a certain terpene or terpene hydrate is also present in rum and may contribute largely to its characteristic flavour. Whether this particular terpene body is peculiar only to Jamaica rum we are unable to say with certainty, but we can at any rate assert that is is not the principal distinctive substance of Jamaica rum. It is always present in Jamaica rum together with the other flavouring constituents, and we have never found it in the artificial product.

Besides the flavouring bodies, other substances which are less volatile come overamongst those are certain resinous bodies which partly dissolve in sodium hydroxide, from which they can afterwards be precipitated by the addition of acids.

As in the case of other potable spirits, aldehydes and volatile acids are found in Jamaica rum. The content in these bodies is subject to very large variations, and here the sophisticator has an opportunity of adulterating Jamaica rum with artificial spirit without surpassing the limits generally found by analysis. The mixing of artificial rum with original rum cannot be practised to any great extent, because by so doing the true flavour is decreased, and the value of the spirit consequently diminished. The adulteration of broken Jamaica rum with artificial rum, to the contrary, is often done. Of eleven samples which we tested for aldehydes, all were found to give distinct reactions. As we shall see further on, artificial run can have as high a volatile acidity as Jamaica rum.

The difficult of judging rum on the ground of its analytical figures is generally caused by the fact that these figures are incapable of expressing the distinctive feature of Jamaica rum, namely the presence of its peculiar flavouring substance. There are, however, certain qualitative tests for Jamaica rum, and what is not shown by a chemical analysis can without difficulty be detected by a trained sense of smell. The usual analytical figures can, nevertheless, corroborate the judgment of a rum, and information of much value can be learnt from them.

The samples which we have examined were: Original Jamaica rum; Jamaica rum broken down with dilute alcoholJamaica rum mixed with artificial rumand artificial rum.

Original Jamaica rum was not often examined, because the sale of this article is confined to special firms and it is only occasionally customers require it tested. The spirit marked “Jamaica Rum” is as a rule broken down with dilute alcohol, and is sold in this form to the customer by all firms dealing with itit is only to be expected that here it is necessary to exert a careful chemical control.

Since genuine Jamaica is the most expensive rum of commerce it is not surprising that the sophisticator marks his product “Jamaica Rum” it is, moreover, not beneath him to apply this title to a product which is nothing more than artificial spirit. This is borne out by the table of analytical results which is given below.

Artificial rum has obviously only the value of the alcohol contained in it. For its production artificial rum essences are used, the cost of which is comparatively low. These substances must be added in small amounts; a certain limit must not be surpassed, for the taste of the product would otherwise be rendered unpleasant. It is for this reason that the ester content of artificial rum is, as a rule, low. The adulteration of broken Jamaica rum with artificial rum is enticing in view of the fact that such a mixture has more or less the flavour of the genuine product and in consideration of the large profits to be gained from such a procedure. It is only fair, however, to the majority of the trade to point that genuine Jamaica rum is sharply differentiated from the artificial that spirit.

In Austria artificial Rum goes for under the names of “Cuba Rum,” “Façon Rum,” “Wirtschafts Rum,” and “Inlander Rum.” The name “Cuba Rum” for an artificial rum is indeed not a strictly proper one, but it is now so firmly established in the trade that it can scarcely cause confusion. Cuba rum, moreover, always indicates a spirit of inferior value to Jamaica rum, and on this account the cost of this artificial rum is considerably lower than that of even the very highly broken genuine product.

The results of our examination of 38 samples of various rums are summarized on the table given on pages 228-229.

Method of on Examination.—As the table shows, the following determinations were carried out: Specific gravity, free acids in the distillate from 100 c.c., and ethers; the characteristic flavouring constituent of Jamaica rum, and foreign flavouring and colouring bodies were also examined.

The alcohol content was calculated from the specific gravity of the sample. As rum contains soluble substances this method is not strictly correct, but it was sufficiently accurate to approximately indicate the strength of the spirit. For an original rum it would be advisable to establish a standard of not less than 70 per cent. by volume of alcohol. In Austria there are no regulations at all as to the alcohol content of rums.

To determine the free acids in the distillate, 100 c.c. of the sample were rinsed into a distillation flask with 15 c.c. of water and the liquid distilled down to about 10 c.c. The distillate was then neutralized with N/10 sodium hydroxide and the result expressed in terms of acetic acid. Jamaica rum has as a rule a greater volatile acidity than artificial rum. The determination of the free acidity in the distillate bears this out, and it is generally found that this value is with Jamaica rum well above those given by artificial rums. The acid value of artificial rum is often strikingly low; it, however, sometimes happens that this value is as high as that of a Jamaica rum when broken down, and for this reason the acid value cannot be regarded as a certain criterion for the judgment of rum.

The ethers were determined by the cold saponification method. To the neutralized distillate, 30 c.c. of N/10 sodium hydroxide were added, and the liquid allowed to remain in a closed flask for at least 24 hours. In the case of concentrated rums N/2 alkali was used.

With artificial rums it was observed that the ester aroma had completely disappeared the next daybut with concentrated Jamaica rum, and even with broken Jamaica rums having a low ester content, the characteristic aroma could be detected after 24 hours, although to a somewhat less extent. By using, however, stronger alkali, viz., a N/2 solution, this aroma more readily disappeared, and gave place to one resembling the terpenes of coniferae.

From the greater power of resistance against dilute alkali of the flavouring constituent, and from the fact that after the disappearance of the ester aroma scarcely any more alkali is absorbed, we have come to the conclusion that the characteristic flavour of Jamaica rum in hardly to be ascribed to the esters.

The ester content of artifical rum is, as we have already mentioned, only small, and cannot be appriciably raised without imparting to the product a bad flavour. In the case of broken Jamaica rum the ester content can be considerably diminished by the dilutionstill, as we show further on, such a spirit can nevertheless be recognized as a genuine one. Although the ester content of original Jamaica rum is subject to very great variations we would have no hesitation in stating that sample 21 in the table marked “Original Jamaica Rum” is not an original rum, and this from the ester content alone without judging from other defects which are indicated by the analytical figures.

The samples 36, 37, and 38 marked Original Rum” came from reliable sources and may be taken as genuinetheir ester content varied those between given in 0.378 and 0-799, which are about which are about the same values as given in Konig’s “Chemie der menschlichen Nahrungs- und Genussmittel.”

It may be asked whether the ester content may be considered a criterion for the quality of a Jamaica rum. The ester content can indicate whether the rum is concentrated or dilute. But the quality of the spirit cannot be judged on the ground of the ester determinationfor obviously the quality of the rum depends not upon the amount of esters but upon their nature and relative proportions, as well as upon the other flavouring substances present. The strength of the aroma of Jamaica rum is indeed dependent upon the peculiar flavouring constituentbut the flavouring constituent is not saponifiable, and therefore is not indicated by the ester determination.

It is to be remarked that during the estimation of the esters in Jamaica rum the liquid assumes a more or less yellow colour according to the extent to which the rum has been brokenbut that with artificial rum the liquid often remains colourless, or is but very slightly coloured. This yellow coloration is due to the greater content of the Jamaica rum in aldehydes, including furfural, than in the case of the artificial product.

We have, however, met with samples of artificial rum which, on saponification, assumed a fine yellow colour, which was not surpassed by even original Jamaica rum. In such cases it is probable that the artificial rum manufacturer had added aldehydes to his product in the hope of more nearly imitating the genuine article.

(To be continued.)

RESEARCHES OF JAMAICA AND ARTIFICIAL RUM.
By Dr. Karl Micko,
Director der Staatlichen Untersuchungsanstalt fur Lebenemittel in Graz.(Continued from page 232.)

Fractional Distillation.Fractional distillation forms the most important method of gauging a rum, for it is thereby possible to concentrate the ethers, ethereal oils, and other aromatic constituents to definite proportions, and to identify them by their smell. For this purpose 200 c.c. of rum were mixed with 30 c.c. of water, and the mixture fractionally distilled. Eight fractions were collected, of which seven consisted of 25 c.c. and the eighth comprised the balance of the distillate. As much of the liquid was distilled off as could be removed without burning the concentrated residue. To carry out the smelling test, glass beakers were employed which were filled each with one of the fractions. According as the liquids adhering to the walls evaporated, the different smells arising from the ethers and other volatile bodies passed off. The first two or three fractions contained besides alcohol a very light volatile ether, also formic and acetic acid ethers. The subsequent fractions gave off smells peculiar to artificial rums and not to Jamaica rums. The typical aromas of Jamaica rums are found as a rule in the fifth or sixth fractions; which depends chiefly on the alcohol content of the original sample, being later in a rich alcoholic rum and earlier in a poor one. In the case of original or concentrated rum these aromas are divided amongst two or three fractions, whereas in diluted rum they are only noticeable in one fraction. As already said, the typical aroma of Jamaica rum is accompanied by a body rich in terpenes. Both bodies are entirely wanting in artificial rum. This terpene body has, however, a less pronounced odour and is less characteristic a proof of Jamaica rum, as in other high class spirits similar bodies rich in terpenes are to be found.

Artificial rum often gives off odours which are practically wanting in Jamaica rum, e.g., of strawberries, cassia or vanillin. These will establish the mixing of artificial with Jamaica rum.

It is to be observed that the aroma test must take precedence over the tasting, as otherwise the sensitiveness of the former will be practically destroyed. If the the tasting is however undertaken first, then the mouth must be well rinsed out with water before inhaling the aromas. The smelling tests should preferably be carried out in the morning hours, as then the sense of smell is stronger than in the afternoon, as smokers can testify.

The last, or else the penultimate, fraction appears turbid in the case of Jamaica rum, providing it has not been diluted too much.

This turbidity disappears on the addition of sodium hydroxide, only to reappear more strongly on acidifying. But if the sample be from an artificial rum the last fraction is as a rule clear. The partial solubility of the heavier volatile constituents of rum in sodium hydroxide is however no proof of a Jamaica rum, as it is a feature of other high class spirits also. Hence it happens that spirits derived from wines sometimes contain relatively large amounts of the heavy volatile bodies insoluble in water, which however consist only in a small degree of the higher alcohols such as amyl alcohol. A part of these bodies dissolves in sodium hydroxide and is reprecipitated on the addition of a mineral acidanother part dissolves only when heated in sodium hydroxide, but remains in solution when cooled, and only when acidified assumes a flocculent or oily turbidity. The smell of the sample is altered by the latter treatment. One is dealing here, it should be observed, with bodies of clearly complex composition somewhat akin to ethereal oils, and which are decomposed or otherwise altered when heated.

The heavy volatile bodies from the last fraction of rum can be separated by the aid of chloroform. Here we find before all others vanillin, which is often added to commercial rum essences and so is found in most artificial rums. If the rums to be distilled to as great a concentration as feasible, the vanillin carried over in the vapour appears equally in the distillate. It is most prevalent in the eighth fractionin the case of strong hydrated rum even the seventh fraction may contain it. In rums which contain over 70 per cent. alcohol it is advisable to mix the highly concentrated distillate with 20 to 30 c.c. of water and then to continue the distillation further.

The three last fractions were shaken up in a separating funnel with about 5 c.c. of chloroform. Since the sixth fraction of a rum rich in alcohol can still contain so much spirit that any separation of the fluids is not possible, it is necessary in such a case to add enough water to the fraction to enable the chloroform to separate from the remaining fluids. The chloroform is run into a beaker, and the beaker placed on a hot water bath. The chloroform must not boil however but only slowly evaporate. It is best to expedite the evaporation of the chloroform by frequently rotating the glass and as soon as the last trace of chloroform has disappeared the beaker should be covered with a watch-glass and laid aside to cool. There upon the smell of the residue can be tested.

The sixth fraction of an artificial rum often reveals a smell of cassia oil and other bodies all foreign to Jamaica rum. The seventh, and the eighth especially, contain vanillin providing this was present in the original sample. The smell of vanillin generally does not develop at once but only after an interval of hours or even days. It is therefore necessary when this smell is not immediately forthcoming to cover the last two samples with a watch-glass, leave them for two or three days and test them from time to time for the smell. It may happen when only a trace of vanillin is present that its smell is hidden by the scent of the other aromatic bodies, which however eventually volatilize or lose their smell owing to some influence such as oxidation, while the more stable and heavier volatile vanillin remains behind and then is gradually detected by its characteristic smell.

In the case of Jamaica rums the chloroform solution produces aromatic oleaginous or resinous residues; but the author has so far failed to detect vanillin in them with any certainty.

For the detection of vanillin in rum he employed the following test:150 to 200 c.c. of rum were made distinctly but not excessively alkaline, and while still alkaline were heated on a water bath to volatilize the alcohol, then acidified with HCl, separated with chloroform, and the chloroform solution evaporated at as low a temperature as possible. The small residue was often resinous and gave off smells which hid that of the vanillin, and sometimes hardly let it reveal itself at all, so that the author had to treat the residue with warm water, filter off the liquid from the undissolved portion and again shake up with chloroform. After evaporating the solution and allowing the residue to stand, the smell of vanillin if it was at all present was as a rule easily detected.

Chloroform is better than carbon bisulphide for the detection of small quantities of vanillin, for the latter has to be freshly prepared for the test, since otherwise it will give off an odour which would affect that of the vanillin. Apart from that, carbon bisulphide on account of its inflammability is not conducible to pleasant working.

This experiment has the disadvantage as compared with the distillation method that on shaking up the spirituous rums with chloroform an emulsion is easily formed, and it needs a longer interval before the chloroform will separate from the aqueous liquid. This disadvantage is absent from the distillation test, as in the latter immediately after shaking up of the aqueous distillate with chloroform the two liquids separate sharply, and there is no need for any further cleansing of the residue from the chloroform solution. Finally, the search for vanillin can be combined in one operation with searches for other aromatic essences.

Foreign colouring bodies are frequently present in concentrated rum. Even if it does not happen that the quality of a rum is judged by its colour, the presence of these colours reveals a case of intentional manipulation and as a matter of fact they are often found in imitation Jamaica rums or in mixtures of Jamaica with false rums, also in broken Jamaica rums that are sold as original Jamaica.

The testing of rums for foreign colouring bodies may, however, prevent any further identification of rum samples, such as may be demanded in legal cases. This concerns in particular the estimation of the ethers and the volatile acids in a distillate, but the alcohol content can be ascertained definitely by means of a hydrometer. As an instance one may cite the samples Nos. 17, 18, and 19, in the tables which were obtained from the same dealer, were produced to all appearance from the same recipe, but had been furnished with labels of different origin and with different specifications.

The tests made on the sample of commercial rums that were submitted to the Untersuchungsanstalt for analysis are to be found in the tables (see pages 228 and 229) numbered from to 34. The author deems it unnecessary to give particulars of more samples than these, as it would only lead to needless reiteration of figures. It is, however, clear enough from the instances cited that there is no difficulty in distinguishing artificial rum from Jamaica rum. One is able, even in the case of strongly broken rums and, within reasonable limits, also in the case of a low content in others as in sample 28, to identify the typical aroma of Jamaica rums. In many samples said to be Jamaican, but which were artificial rums, traces of this aroma of Jamaica rum were detected. The writer ascribed this to their being mixed with small amounts of Jamaica rum and in order to confirm the theory of his supposition he interrogated the spirit merchants and their their their answer was invariably that they added some Jamaican rum to their “Wirtschafts,”Cuba,” and artificial rums in order to improve their flavour. It must, therefore, not be overlooked that for similar reasons some Jamaica rum may be added to artificial rum essences whereby the peculiar taste will be imparted to them.

Additions of artificial rums to Jamaica rums yield aromatic bodies not found in the latter. But a more difficult task awaits one when only a small addition is under test, for then the adulteration may be hidden by the aroma of the Jamaica rum. In such a case it is advisable to fractionally distill a larger quantity than 200 c.c., and then to separate the individual fractions by further distillation. The artificial rum is less visible in the first fractions than in later ones, for both in Jamaica and in artificial rums the most volatile constituents consist mainly of the esters of formic and acetic acids and of alcohol. The first distillates of artificial rums have however a more obtrusive smell than have Jamaica rums, and this smell is also of a kind not found in Jamaicas, so that a case of adulteration is easily proved. Besides there are differences in taste and smell in the case of false rums. Many of them are at once detected by their strong smell of artificial ethers and vanillin. Others have a more finished aroma and taste, according as the distiller has the greater skill in the preparation of the artificial rums. In the tables we find No. 25 described as a Porto Rico rum; this was marketed with considerable advertisement. It contained a striking amount of cassia oil, and had also every indication of being a false rum. In the column, “Flavouring Substances foreign to Jamaica Rum,” the only adulterants mentioned are vanillin and cassia oil. But that does not imply that only these and no other foreign matters were present. They have only been cited because they are more easily identified by smell, and, especially vanillin, are very commonly found in false rums, while other aromatic bodies observed, if they are not found  in Jamaica rums too, are much more difficult to identify.

The difficulty of imitating the aroma of rum does not lie so much in the accurate selection of ethers as in the circumstance that the typical smell of Jamaica rums arises from bodies which either belong to the class of ethereal oils, or stand in close relation to them, but have no definite formula. Windisch was right in speaking of “ethereal rum oils,” which he he had obtained by the separation of rums with chloroform.

E. Sell, from his own investigations into the composition of rums, comes to the following conclusion. “The opinion expressed at the conclusion of some investigations on cognac, to the effect that it was impossible to distinguish genuine from fictitious liquors by mere chemical tests, is not a bit less opposite in the case of valuing rums. Here also the preference must be given to such expert opinion as bases its decision on the taste and the smell of the sample.”

It is thus the case that the figures obtained through chemical analysis are not by themselves reliable for distinguishing artificial from Jamaica rums, but must be supplemented by investigations into the taste and smell. Any analyst who has a sensitive nose and palate can not only distinguish Jamaica rum from artificial rum, but also a large proportion of the cases where the two have been mixed. In virtue of his wider knowledge of chemical bodies and through suitable experimentation in the laboratory, the analyst is in a better position to detect the foreign bodies not found in Jamaica rum than is the practical expert. But estimations of price and quality fall necessarily within the latter’s sphere.

[To be continued.)

RESEARCHES ON JAMAICA AND ARTIFICIAL RUM.
By Dr. Karl Micko,
Director der Staatlichen Untersuchungsanstalt fur Lebensmittel in Graz.(Continued from page 414.)

II. The Identification of the typical Flavouring Body of Jamaica Rum.

For the identification and nearer characterization of the peculiar flavouring constituent of Jamaica rum, I proceeded in the following manner:—

1900 c.c. “Original Jamaica Rum” (No. 38, page 229) was fractionally disitlled, eight fractions (I.-VIII.) being collected. Fractions I. and II. possessed a very distinct smell of formic and acetic esters, Fraction IV. a smell of butyric ester. The specific aroma which characterizes Jamaica rum appeared in Fraction V. but only feebly. It was quite distinct, however, in Fraction VI., and strongest in Fraction VII. Fraction VIII had an acid and an aromatic smell; it was cloudy and oily drops floated on its surface.

Fractions V. and VI. were mixed together and the mixture fractionally distilled, four fractions (I.-IV.) being collected. The first two of these fractions contained no typical aroma, and in the third fraction it appeared only to a very small extent. It existed strongly in the fourth fraction together with a body of a terpene-like odour. This fourth fraction was mixed with Fractions VII. and VIII. of the original distillation, and the whole fractionally distilled into five fractions (A-F).

Fraction A had only a little rum aroma; it was much stronger  in Fraction B, but Fraction C contained the chief quantity  of the peculiar flavouring constituent. In all three fractions was present the above mentioned terpene-like body (reminding one perhaps of juniper oil). Dilution of these three fractions produced turbidity.

Fraction D was turbid and watery, and did not possess the characteristic rum aroma, its smell being rather of other aromatic bodies. It was shaken up with chloroform, the chloroform solution separated, and the chloroform carefully evaporated away. It left behind a yellowish, resinous substance of the aromatic smell, which dissolved in caustic soda, and on acidification was reprecipitated. It is questionable whether this resinous substance is an original product of the fermentation. On the other hand many aldehydes incline to condensation, forming resinous substances which behave in the same way as the above with alkalis and acids. It is quite probably, therefore, that aldehydes are concerned in the formation of the aroma of brandy.

At all events, aldehydes react readily with alkalis. Grey says the specific rum aroma is produced by the action of lime on sugar solutions during its manufacture, and it is not impossible, therefore, that aldehydes are concerned in the production of the peculiar rum aroma. By the following experiments it will be seen that the peculiar flavouring constituent of Jamaica rum assumes another smell by the action of caustic soda. The formation of the rum aroma would be best studied by investigations during the different phases of manufacture.

Fraction had only a slight smellit was turbid and was shaken up with chloroform. The chloroform substance resembling that obtained solution left on evaporation from Fraction D. Fraction F had hardly any smell. Fractions A, B, and C all gave the aldehyde reaction on additions of Schiff’s reagent, and the furfurol reaction with aniline acetate. The aldehyde reaction was strongest in Fraction A, and weakest in C, but Fraction C behaved in quite the opposite manner with the two reagents. The following experiments were undertaken with distillates B and C :—

Experiment 1.

Since all signs tend towards the fact that the peculiar flavouring body of Jamaica rum does not belong to the esters, it remained to be proved whether it was not due to an aldehyde or ketone group which may be present. may be present. To decide this question I made use of fraction B and C. treated 5 c.c. therefrom separately with phenylhydrazine, hydroxylamine and semicarbazide. Fraction B was closely observed for change of smell, because it did not contain so much of the typical flavouring body, and any changes would, therefore, be noticed more quickly than Fraction C. But even after one week the typical aroma was recognizable, the phenylhydrazine test only having less smell, yet still quite recognizable, and, therefore, no reaction with either of the three reagents had taken place.

By the negative result of this experiment, it is not probable, therefore, that the typical flavouring body of Jamaica rum belongs either to the aldehydes or ketones.

Experiment 2.

The chief quantity of Fraction B was first treated with a saturated solution of sodium bisulphite, whereby any traces of aldehydes were removed, and the mixture shaken up with ether, whereby the typical flavouring constituent passed into the ether. The separated bi sulphite solution give out no aroma on treatment with dilute sulphuric acid.

The ethereal solution was shaken up with sodium carbonate in order to remove any sulphurous acid present. The typical aroma remained unchanged. The ethereal solution was separated and subjected to careful distillation on a water bath, the ether passed over first containing no typical aroma, then followed the alcohol together with the typical flavouring constituent. The aroma was not very pure or strong since Fraction B contained only a small quantity of the typical flavouring body.

Only a part of the alcohol was distilled off. The alcoholic distillation residue exhibited no distinctive smell of the typical flavouring body of the rumit was distinctly alkaline. Probably a slight trace of sodium carbonate remained in the ethereal solution thus causing the alkaline reaction of the residue. The latter was treated with excess of ether, the ethereal fluid separated the next day and the ether carefully distilled off on the water bath. The small quantity of alcoholic residue remaining from the distillation had a pronounced terpene-like odour reminding one of juniper oil, such as have continually noticed to be present with the peculiar flavouring constituent. The neutral reacting fluid gave only a feeble furfurol reaction, but with a distinct dstinct though no strong reaction with Schiff’s reagent. It still contained, therefore, a trace of aldehyde but the principal amount was at all events removed. the alcoholic residue was mixed with 10 c.c. N/2 NaOH, which produced a turbidity and also a yellow coloration on standing. The smell of terpene was preserved for some days. By titration with acid it was found that only 0.10 c.c. of NaOH had been used.

The titrated fluid was again made alkaline and shaken up with ether. The ethereal solution left behind after the evaporation of the ether a yellowish, aromatic terpene smelling like oil. The other part of the liquid turned cloudy on acidification with dilute hydrochloric acid. On shaking up this cloudy solution with ether and separating them, evaporating off the ether, only a trifling quantity of a brownish yellow oil was left whose aroma was not aromatic.

From this experiment it follows that the typical flavouring constituent does not enter into combination with sodium bisulphite as the aldehydes do to form an oxysulphonic acid. The terpene-like body which is present with the typical flavouring constituent is not soluble in dilute sodium hydroxide, and suffers no loss of smell through prolonged contact with the same. This body belongs at all events neither to the esters nor to the aldehydes.

Experiment 3.

This was conducted on Fraction C, which contained the chief quantity of the typical aroma. It was to distillation until a little alcohol passed over. The distillation residue is called (a), the distillate (b). Both (a) and (b) showed strongly the typical aroma, but the aroma from the distillate was much purer than that arising from the residue which smelt besides of the before mentioned terpene- like body and also of other aromatic bodies.

The residue (a) was cloudy and on the surface thereof swam drops of oil. It was very was carefully neutralized with barium thereof hydrate and diluted with water, shaken up with ether, separated and the ethereal fluid carefully distilled, so that nearly all the ether and only traces of the typical flavouring body distilled over.

The residue left amounted to only a few c.c.it reacted feebly acid, and a strong but not pure smell of the typical flavouring constituent. The trifling quantity of acid was neutralized with very dilute sodium hydrate and then 30 c.c. N/2 caustic soda was added. The alkaline solution with the oil drops after a time turned strongly yellow. After four days the smell of the typical flavouring constituent disappeared, and a peculiar aromatic smell took its place. The terpene smell was, however, very distinct. On titration with acid the consumption of N/2 caustic soda was found to be 0.9 c.c. The titrated fluid was again made alkaline and shaken up with ether. On separation and evaporation of the ethereal layer an oil was left behind, similar in smell to that obtained in Experiment 2. The other layer of liquid was submitted to distillation in a current of steam in order to see whether it contained any volatile acids.

About 400 c.c. of distillate was collected which was slightly cloudy only and reacted almost neutral. Evidently it contained volatile acids in only small quantities. It was made alkaline with barium hydrate, evaporated to dryness, the residue extracted with hot water, then filtered and the filtrate evaporated to dryness. The residue left was very small, and on the addition of two drops of dilute sulphuric acid a smell resembling that of butyric ester was formed.

The quantity of this substance was so small that it at all events did not correspond to the residue which required 0.9 c.c. N/2 caustic soda for saponification. The residue left from the extraction with hot water did not dissolve completely in hydrochloric acid. A white turbidity of the hydrochloric acid solution was caused through a fine flocculent substance, which did not dissolve in ether, but in alcohol. The quantity was so small, however, that it could not be put to further test.

The distillate (b) contained the typical flavouring body in its purest form. For the purification and isolation of the typical flavouring constituent the distillate (b) was strongly diluted with water, then shaken up with ether, and the ethereal solution further shaken with water. The typical flavouring body always remained in the ether which was distilled off very carefully at a temperature of 30°C so that ether and practically none of the flavouring constituent distilled over. The alcoholic residue amounting to about 50 c.c. was diluted with water several times in order to remove the alcohol, then mixed with ether, the ethereal solution washed several times more with water  and separated. It amounted finally to approximately 30 c.c.

5 c.c. of this left behind, after evaporation of the ether at room temperature, colourless drops of a fluid which possessed the typical aroma of Jamaica rum very intensely, and which in one hour completely volatilized and filled the laboratory with the characteristic aroma of Jamaica rum.

The aroma is more characteristic in the dilute than in the concentrated condition, and its boiling point certainly is higher than that of ethyl alcohol, yet it evaporated at ordinary temperature fairly quickly. When rum is rubbed on the palm of the hand the typical aroma can be detected for a fairly long time, and it seems, therefore, that Jamaica rum contains more difficult volatile bodies than the typical one, this being held in solution longer, thus preventing quicker volatilization. When the rum is fractionally distilled the typical constituent is concentrated in one or two fractions, and the aroma from these fractions is much stronger than in original rum, also evaporating more quickly out of the palm of the hand than in the case of the original rum.

A further 5 c.c. of the same ethereal solution was taken and shaken with 5 c.c. of N/10 sodium hydrate for some minutes, the alkaline fluid separated off, and the remainder washed with water until neutral. The typical flavouring body remained unaltered and is, therefore, not soluble in sodium hydrate. On treating this ethereal solution with 10 c.c. N/10 sodium hydrate and leaving for four days in a lightly corked flask with periodical shaking up, the smell at the end of this time was decisively altered, being certainly aromatic, but not corresponding with the typical flavouring body. The consumption of N/10 NaOH was found to be only 0.15 c.c. on titration with acid.

The same experiment was repeated only with this difference that the saponification was carried out by heating for half hour on the water-bath under reflux condenser. Only 0.1 c.c. of N/10 NaOH was used in this case, and the smell was altered as in the preceding case. 

The titrated fluid was again made alkaline, shaken up with ether, the ethereal layer separated, and after gently warming the remaining fluid on the water-bath to expel traces of ether it was acidified with dilute H2SO4. From both tests a scarcely perceptible turbidity was produced, and no smell was apparent.

For the third experiment 10 c.c. of alcohol (previously distilled over caustic soda), 10 c.c. N/10 caustic soda and c.c. of the ethereal solution which had been shaken with dilute caustic soda, were mixed together. After half an hour’s heating on the water bath under reflux condenser, the titre of the fluid remained almost the same. The smell was, however, altered as by the first two tests. From all investigations with distillate (b) no yellow coloration took place by the action of alkali, as was the case with the residue (a). The yellow coloration produced in (a) would probably be due to aldehydes or furfurol in small quantities, but the amount of alkali used was so small that it could hardly be attributed to aldehydes. When an alkaline solution of furfurol is allowed to stand, however, a yellow colour is produced at first, afterwards turning cloudy. By the acidification of this turbid alkaline solution, a reddish brown flocculent precipitate is thrown out.

As the investigation with Fraction B proves, the typical flavouring body does not combine with alkali. The absence of a yellow colour points to the fact that it cannot belong to the aldehydes. We have from the earlier experiments seen that no combination is effected with ether phenylhydrazin, hydroxylamine and semicarbazide. Neither does it combine with sodium bisulphite. On the other hand, caustic soda alters the smell of the typical flavouring constituent slowly in the cold, but more quickly in the warm, but no saponification takes place however.

Summary of Results

From the above investigations the following conclusions may be drawn:—

1. Jamaica rum contains an aromatic constituent peculiar to it alone, which is the basis of its characteristic flavour. This constituent is found neither in high class European spirits nor in artificial rum.:

2. This typical flavouring body of Jamaica rum is a colourless not difficultly volatile fluid of a delicate aromatic smell and its boiling point lies higher than that of ethyl alcohol.

3. This typical belongs neither to the esters, ketones, or aldehydes. It has the general characteristics of an ethereal oil, and it is not improbable that it stands in nearer relation to the terpenes.

4. The typical flavouring body does not dissolve in caustic soda, but on prolonged contact with it, it assumes an aromatic but more resinous smell.

5. In Jamaica rum as in other high class spirits is a body possessing a terpene-like aroma which is entirely absent from artificial rum. But it is less characteristically a proof of Jamaica rum as in other high class spirits similar bodies rich in terpenes are found.

6. In Jamaica rum there occurs in the last distillation fraction an aromatic smelling, resinous substance, which dissolves in caustic soda and is precipitated by the addition which of acids. It is questionable whether this substance is a primary fermentation product. For we can produce such substance easily from aldehydes.

7. The analyst with sensitive nose and palate can easily distinguish artificial from Jamaica rum. He is also in the position to be able to detect mixtures of Jamaica with artificial rum.

8. From chemical analysis alone, however, no thorough conclusion is possible but when used in conjunction with the smelling test it is extremely valuable. The ester number is of especial value for deter mining whether the given sample is of a concentrated or a diluted rum.

THE CHEMICAL EXAMINATION OP VARIOUS RUMS.
By Karl Micko.

In a previous article (this Journal, 1909, 225, 410, and 446) we have dealt with the examination of rum, and have attributed the great difference between Jamaica and artificial rums to the presence of a typical aromatic constituent in the former. We have now extended our studies to other kinds of rum, especially Cuba and Demerara rums, and to different arracks. The special object in view was to determine whether Cuba and Demerara rums contain the same typical aromatic constituent, and to find out in what way these two kinds differ from one another.

Our previous work has shown (loc. cit.) that the typical aromatic constituents of Jamaica rum is more resistant towards alkali than the esters; for whilst the esters are completely saponified by an alcoholic N/10 caustic soda solution in 24 hours at ordinary room temperature the typical aromatic odour persists to finally give place to another more resinous smell.

It was inferred that by carefully saponifying the esters it would be possible to separate the peculiar aromatic constituent, and this was found to be actually so. First the ester content of a portion of distillate was determined using an excess of alkali, then to a second portion of distillate less alkali was added than sufficed for the saponification of the esters. The amount of caustic soda added was less than that actually necessary to effect saponification on account of the fact that the aldehydes readily decompose
in alkaline solution forming acid products. In the case of this happening the odour would be affected; but our main object in working with as small amount of alkali as possible was to avoid attacking the non-ester constituent.

The distillate thus treated was alkaline, completely but the excess of  alkali was slight as the esters were almost completely saponified. It was then acidified with tartaric acid, and submitted to fractional distillation.

Working in this way we examined not only the above-mentioned tropical spirits but also some European products; and our conclusions may be summarized as follows:–

All the spirits examined possess a peculiar aromatic constituent which does not belong to the esters. It is possible aromatic by means of the above-described method to readily differentiate between artificial spirits flavoured with esters, etherial oils, and other substances and the genuine product. This peculiar aromatic constituent is of great value in judging the purity of spirits, and is in this connection of greater significance than the esters. It
imparts most of the specific aroma to the spirit. It is a general criterion, and has not been imitated up to the present time. It can be separated by carefully saponifying the esters, and has an extremely delicate fruity odour.

The tropical spirits which were examined, Cuba, Demerara, and Jamaica rums, and Batavia arracks, contain in addition to other flavouring constituents the same, or a very similar aromatic constituent, as the one we obtained from Jamaica rum (this Jl., 1910, 225 et seq.), but in Jamaica rum it is present in much greater amount.

In Jamaica rum it can be detected by fractional distillation of the original rum, or even by strongly breaking down; whilst in the other spirits, since
it occurs in much smaller amount and in admixture with other specific aromatic bodies and esters, it can only be recognised by carefully saponifying the esters and fractionating the ester-free liquid thus obtained.

Besides the fragrant-smelling bodies another body of a characteristic odour which generally appeared in the last fractions of the fractional distillation was found in the tropical spirits.

As to the origin of the typical aromatic constituent, it may either be formed during fermentation, or may be present as such in the primary material.
In the case of Jamaica rum the first supposition is probably true. Perhaps there are present in the sugar cane certain bodies which during fermentation give rise to the aromatic substances; or again possibly the aldehydes, ketones, &c, react during the production of the spirit with the formation of the aromatic bodies.

The results of our analytical examination of the various rums are given in the following table:—