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

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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.


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:
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.

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