A reference to this paper crossed my desk and I took a new stab at tracking it down. It appeared in Rafael Arroyo’s bibliography for Studies on Rum but he had it listed as 1931 instead of 1921. No wonder it could not be found!
Haupt, A. Uber Deutschen Rum. Zeitschrift für Öffentliche Chemie. 1921
Arroyo references it as such:
Haupt (14) in his recent work on German rum claims that the nature of the fermenting yeast plays the principal role in the development of rum aroma, even superior to the nature of the raw material used in the composition of the mash. While this is a far reaching assertion, we cite it here in order to demonstrate the paramount importance of selecting the right class of yeast for rum fermentation.
This was a decade older than Arroyo thought so not exactly recent work writing from the 1940’s. What we find is that Germany was producing a type of heavy rum from their native beet sugar as opposed to sugar cane and government scientists who examined it had to determine if they could call it rum or not. The paper compares it chemically to authentic Jamaica rum as well as a few other rum types. A comment section at the very end contains some interesting dissenting opinions. At the end, they mention a future paper and that may be from Brauer in 1922.
Something else very important to the paper is that the author describes adding specialty dunder after fermentation has already become vigorous. I do not recall this being spelled out anywhere and there are reason it may be advantageous if the dunder had the correct composition. It is commonly known that molasses is often added in stages, but not dunder. The author also uses many analysis methods such as Karl Micko’s birectifier for the evaluation of the spirits. Could this be the paper where Arroyo learned about the birectifier?
Something to also note is that this “German rum” is not the ultra heavy continental marks produced in Jamaica and nicknamed German rum because of to whom they were sold. This “German rum” is an attempt at heavy grand arôme rum produced from sugar beets, but likely also intended to be used as a blending product. It sounds like they were more successful than previous attempts, though I bet they are overstating the quality, and you wonder if it survives in any form or was put out of business due to the coming war.
[It turns out this paper was already translated into English (but abridged) in The International sugar journal. v. 24 (1922) pages 33-35. I did not find this until a week later, but it does make my translation look very good.]
About German Rum
German industry registered a remarkable new advance in the fermentation trade. The previously unsuccessful attempt to present a product made from local raw material that is similar to rum or has a very similar character has now been brought to a happy conclusion. After twelve years of efforts, the Hünlich company in Wilthen (Saxony) is able to produce German rum from beet juice or raw sugar, molasses and and waste from sugar production using fermentation technology.
From observing rum production in tropical countries, it is sufficiently clear that it is not the type of sugar used, but rather the production process that plays the decisive role in the extraction. [History shows this is overstated and I have tasted a few experimental beet molasses rums that had odd unnerving aroma. The producer gave up and switched to cane.]
Attempts continued despite initial failures, through exact adjustment to the tropical fermentation conditions and correct selection of organisms to produce rum from German raw material, finally have led to a product that regarding smell and taste and in its chemical constants almost equals real rum of medium quality and is superior to imported rum of lower quality in the delicacy of the aroma according to the taste tests carried out by numerous experts tasters and other test persons.
Presentation of the import rum.
Contradictory information can be found in the older literature about rum production. Only in the work of Sell (1), which is largely confirmed by the publication of the English “Whisky Commission” (2), is the correct information compiled.
[Sell’s papers have not been recovered yet:
SELL (E.) — Ueber cognak, rum und arak. Arb. Kaiserl. Gesundh. VI, 335-373, 1890. VII, 210-252, 1891.
SELL (E.) — Ueber Cognak, rum und arak ; das material zu ihrer darstellung, ihre bereitung und nachher behandlung unter berücksichtigung der im handel üblichen gerbraüche sowie ihrer ersatzmittel und nachahmungen sowie die ergebnisse ihre chemischer untersuchung. Berlin, 1891. [About cognac, rum and arak; the material for their preparation, their preparation and subsequent treatment, taking into account the customary odors in the trade and their substitutes and imitations, as well as the results of their chemical examination.]]
(1) Arbeiton 8th. a.d. Kaiserlichen Gesundheitsamt 1891. [This full citation needs pursued.]
(2) Royal Commission on Whiskey and other potable spirits.
The main starting material for rum fermentation is then the molasses that remains after the raw sugar has crystallized out of the sugar cane juice (3). According to James Coneys Nolan, whom the Jamaican government sent to London in 1908 to represent the interests of the rum producers there, the sugar cane is milled and pressed on roller mills, and the resulting juice is fermented in vats. Protein and sugary foam that separates in abundance during the beer forms the skimmings. These foam masses and the rinsing water from the tanks are fed into the distillery, where they are subjected to acidic fermentation lasting several days, and, in order to accelerate the fermentation, with pressed out Sugarcane (called bagasse)—which apparently plays a certain role in fermentation as a carrier for yeast cells and carbonic acid—released. Then you add the molasses, i.e. the clarified boiled press juice of the sugar cane remaining after the separation of the first crystallization of the cane sugar, as a result of which the fermentation liquid now becomes significantly richer in sugar. In some countries, the very low-sugar molasses, from which sucrose is harvested two or three times, are processed into rum. The mash, which is now undergoing strong fermentation—namely in spontaneous fermentation in the tropics—is mixed with the “dunder” before its distillation, i.e. the stillage residues from previous distillations, which have been fermented again for themselves, are added. The way this Dunder is fermented is given special attention in Jamaica, less so in Cuba, while cultivation or addition of dunder in some other countries is completely disregarded. Correct treatment of the dunder seems to be of particular importance for aroma formation in the mash or in the finished rum. Higher molecular weight, less volatile acids are probably retained in part in the stillage during the first distillation, and esterification and aldehyde formation are only likely to take place after repeated fermentation by the influence of certain fermentation organisms in these protein-rich residues. Finally, according to Jamaican producers, it is of great importance for the production of rum that the rum is distilled in ordinary pot stills, not in modern column apparatus.
[It is not commonly acknowledged that dunder can be added before distillation. It is hard to say where the information comes from. The author could also be confusing dunder for muck which they may not have a concept for. Until very recently, all spirits enthusiasts only talked of dunder pits and not muck holes which were an unknown concept.]
The way in which rum is produced in other cane-sugar producing countries, such as Cuba, British Guyana, the West Indies, Martinique and Brazil, deviates considerably from the presentation given above. In particular, additions of aromatic and tannic substances, such as the bark of a certain species of acacia, the leaves of Aeona squamosa, and peach leaves (Madagascar) to the still are common practice. According to Robinson, the sugary sap of the date palm was also used in the East Indies (4) to make rum. It would lead too far astray to go into detail here about all the numerous relevant references.
(3) Vergl. auch Stohmann nach Muspratts theoretische, praktische und analytische Chemie, B. Auflage.
(4) “The Bengel Sugar Planter”, Kalkutta 1889.
Production of German Rum.
The procedure worked out by Herr Fritz Hünlich is now closely based on the methods customary in the West Indies. Fermentation takes place in temperature controlled rooms, at the high temperatures usual in the tropics with specific fermentation agents in several separate courses. Beet molasses is fermented on its own and from the stillage remaining during distillation, with the addition of cane sugar, nitrogenous residues and fruit, a Dunder is prepared by subjecting this mixture to bacterial fermentation in highly heated rooms. Here, in addition to fragrant aromatic substances, undesirable bodies are also formed, which are separated using a special process. This prepared Dunder is now added to the fermenting molasses mash, in a certain proportion, before distillation. It is clear that the type of fermentation organism plays the most important role in rum aroma development, and it is obvious that attempts have been made to breed and inoculate fermentation pathogens in pure cultures, similarly, H. Becker, for example, succeeded in producing a good rum by introducing cuban rum yeast in German East Africa. Not the type of sugary starting material used, whether it be from sugar cane or from sugar beet, but the type of fermentation organisms and exact adjustment to their most favorable living conditions, such as mash acidity, air supply and fermentation temperature are therefore decisive for rum character. If the earlier attempts to produce rum from sugar cane molasses imported to Europe were unsuccessful and, as A. Gaber reports, (5) “only ordinary brandy was produced during fermentation”, the only reason for this may have been the type of fermentation organisms used and the fermentation process. Knowledge of yeast species and fermentation bacteria was then insufficient. Addition of properly cultivated Dunder prepares a good breeding ground for colonization of acetic acid and butyric acid bacteria in tropical rum according to Stadlinger, which in turn provides far more favorable conditions for yeast growth in the molasses mash than in German sugar solutions. This promotes formation of esters in the mash, on which rum’s own smell and taste are particularly dependent.
[What we see described at the beginning looks more like dunder than muck. It is not clear what the fruits could be. When jackfruit is used at Hampden, the likely active ingredient is not a microorganism it contributes but rather pantothenic acid which supports growth of bacteria. Sometimes tomato juice is used for lactic acid bacteria starters in the wine industry.]
(5) Die Fabrikation des Rums. Hartleben 1898.
In any case, dunder also plays an important role in the production of German rum, since it is fermented in a completely different way than the other parts.
Distillation then usually takes place in a modern apparatus, an alcohol that is particularly rich in esters being passed as the forerun. Subsequent alcohol, which has small amounts of ester, is then mixed with certain portions of the forerun, the so-called high-wines, blended together, results in the various commercial qualities of German rum. The small fluctuations that still occur here and there in the chemical composition of the product also depend on the fact that different organisms (bacteria and yeast species) are involved in fermentation, sometimes at the same time, but it cannot be avoided that one race or the other will gain the upper hand. This fact is to a far more pronounced degree of the production of the real rum, the differences in the qualities of the same are primarily due to them. (Compare the findings of J.C. Nolan, according to which the main qualities of Jamaica rum, which differ greatly in terms of the content of aromatic substances, are obtained through different fermentation processes, i.e. in other words, through the presentation of different living conditions and promotion of the emergence of certain races of fermentation organisms.)
Comparison of real tropical rum and German rum.
Rum character as a fine distillate is determined by its own aromatic substances, which vary considerably in type and strength in the individual commercial varieties, but are just as little lacking in a common characteristic as other pure fermentation products, e.g. Wine or beer, for example, which also have very great differences in appearance, smell and taste and in their chemical composition.
Incidentally, when assessing the value of rum, it is not just its content of esters, acid, i.e. its chemical composition, that alone is decisive, but smell and taste, aromatic subtlety and wholesomeness play a major role in the commercial evaluation of rum, as in that of other fine spirits.
The comparative smell and taste samples of three different marks of German “Rum” with genuine Jamaican rums obtained from the free trade, the authenticity of which has been proven by chemical analysis, or which had been imported into the country under customs seal and came from first-class import companies, was now employed in such a way that the rum samples brought to the same alcohol content with soft water were marked with numbers and tasted comparatively by different people, including several expert tasters. In addition, by adding hot water and sugar, grog was made and also tasted. In some cases, in order to determine the wholesomeness of the grog made from German rum, it was consumed in somewhat larger quantities. The result was that almost all taste testers unanimously addressed the “German rum” as being completely equal to the Jamaican rum of medium quality. An aroma that differed from real rum in some respects and was reminiscent of the origin from sugar beet material was only noticed by a person who apparently had particularly fine tasting skills. All observers agreed that Jamaican rum of inferior quality, which in our current economic situation is apparently being imported to Germany to a greater extent than in the past, lags far behind German rum in terms of the delicacy of aroma and wholesome taste. First quality Jamaican rum showed a finer and more extensive aroma than German rum, such that medium quality is to be regarded as equivalent to German rum. Incidentally, numerous other colleagues who have dealt with the testing of new products, such as Härtel, Heiduschka, Krug, Lintner, Stadlinger, as well as Mezger and Jesser, come to the same conclusion with regard to the organoleptic test, their very detailed and varied studies of German rum I don’t want to anticipate here.
[The hot grog test is a great one to remember, and they even admit to drinking it excess to check the hangover!]
As far as methodology for the chemical analysis of the rum is concerned, fractional distillation according to Micko is used for the qualitative determination of the content of by-products of fermentation, as expressed in the so-called impurity coefficient, which is expressed in the Lusson-Girard number, decisive for the quantitative test. Since the latter, however, varies within fairly wide limits even in the case of tropical rums from different and identical countries of origin, one must not be too narrow-minded in their assessment.
[They would have used a birectifier for Micko’s method of fractional distillation. Micko was pretty much the first person to describe rum oil.]
After all, the Lusson-Girard number for testing quality differences of distillate has undoubtedly proven its worth in practice alongside the organoleptic test, and it also allows in almost all cases to detect counterfeiting of rum through any artificial rum additives.
In the examination according to Micko, the corresponding investigations of many well-known food chemists revealed the pre-establishment for rum, specifically for Jamaica rum, typical odorant in the fifth or sixth fraction and the continued presence of fine odorants, similar to those found in the fractionation of Martinique rum, in individual earlier fractions. The smell was not always as strong in the last fractions as with some genuine Jamaican rum varieties. However, its clear presence already showed the extensive similarity of the new product with genuine Jamaican rum.
[This paragraph is all about comparisons of rum oil. Rum oil, which is basically damascenone, shows up in the fifth fraction, but when it is abundent it carries into the later fractions.]
In the preliminary test with concentrated sulfuric acid (10 ml rum + 4 ml sulfuric acid, specific weight 1.84), the German rum still clearly showed its characteristic fragrances after 12 hours, as do genuine Jamaican rums in contrast to artificial products. After 24 hours, the aroma was no longer as strong as in the samples of real rum used for comparison.
[What we see here is the sulfuric acid test, and the authors uses 90% pure acid]
The large fluctuations in the fermentation coefficient (contamination coefficient) in Jamaican rum, which is undoubtedly of genuine origin, are most clearly evident from the information provided by the official English statistics in their report, in addition to the numerous analyzes by other authors.
Calculated on 100 ml absolute alcohol, the first seven types of rum contained in the overview resulted in the following values :
total acid, calculated as acetic acid:
esters, calculated as ethyl acetate:
aldehyde, as acetaldehyde:
The resolution of the Fourth International Congress of Applied Chemistry in Rome, according to which it is not advisable to set upper or lower limits for the total amount of secondary components in fine spirits, is illustrated by these examples, which could easily be supplemented with those of fluctuations of greater amplitude, understandable. (8)
After all, a comparison of the German rum we examined (designated M), which was handed over to me under official customs seal, with an undoubtedly genuine commercial Jamaican rum and with an original commercial Jamaican rum also described as “genuine” and not without value.
(6) Royal Commission on whisky usw.
(7) Vergl. von Buchka: Das Lebensmittelgewerbe.
(8) Vegl. bierzu die Arbeiten von E. Sell; Arb. an d. Kaiserlichen Gesundheitsamt, 1891, Bd. 7,8, 210, K. Windisch ebenda 1893, Bd. 8, S. 278. —Konig: Chemie de menschlichen Nabrungsund Genusmittel, Bd. 1, S. 1410 bis 1413; Bd. 2, S. 1352 bis 1355, von Jonscher, von Polenske, Micko, Mansfeld u.s.m.
[This last citation is a compendium of German agro chemists who had investigated Jamaica rum.]
According to Jonscher, who examined German rum as early as 1914, its aroma resembles that of the fine-flowered Martinique rum more than that of Jamaica rum. Therefore, some types of German rum that we examined are compared to the Lusson Girard numbers for Martinique rum:
These comparisons show that German rum is very similar to tropical products in terms of the content of secondary components of fermentation. In terms of the content of higher molecular volatile acids and esters, it is on a par with the tropical products of average quality, while imported rum of low quality is surpassed by the numbers of German rum and in the actual delicacy of the aroma. Some of the flavorings that do not belong to the esters are more similar to the flavorings contained in Martinique rum than to those of Jamaican rum. They are particularly noticeable in Micko fractional distillation. At the same time, fractional distillation shows that any artificial products made from esters, essential oils or any similar substances and spirits are by no means contained in German rum. The fact that it is practically free of methyl alcohol and any kind of pungent brandy may be taken for granted from the outset in the case of a real fermentation product.
My various investigations of German rum and the repeated inspection of the rum production at the producer have led me to the conclusion that the new product is to be addressed as “rum” because, according to the results of the comparative smell and taste test, as well as the result of the chemical analysis represents a high-quality pure fermentation product which, in most relevant points, shows extensive agreement with real varieties produced in the tropics, and for which the designation “German rum” seems entirely appropriate. With regard to the delicacy of the aroma and versatility, i.e. in terms of its practical value, German rum surpasses some of the real rum varieties that have recently been introduced. Its character is quite similar to a real rum of medium quality. The differences in the aromatic substances, which are still recognizable between German rum and imported rum on closer examination, should probably be overcome over time, since the whole of the manufacturing processes in the production of rum in tropical countries often differ greatly from one another because the type of starting material containing sugar is less responsible for the quality of the fermentation product than the type of fermentation organism and the fermentation conditions.
The new product undoubtedly has a very considerable economic importance, especially given the current economic situation in the Reich. The progress in fermentation technology, which made it possible to produce a product from beet sugar that is essentially the same or very similar to rum made from the chemically identical “sugar” of cane sugar, is to be warmly welcomed.
There is no need to examine whether the new product is entitled to be called “German rum” under the existing legal provisions.
According to the previous terms (9), such a drinking brandy was to be regarded as rum “currently” which was obtained in the producing countries from the juice, effluent, skimmings and other residues of the sugar cane through fermentation and distillation according to the usual recognized processes. The version of the guidelines for the assessment of rum at that time expressly left the question open with the words “currently” as to whether it might be possible in the future to produce “rum” from other raw material using recognized fermentation processes, which, according to the work of Herzfeld et al. even then did not seem impossible. If the Hüplich company has now succeeded in producing a rum from German beet sugar products that is essentially similar to real rum and has all the characteristic properties of the former, then there is no reason to withhold the designation “German rum” from this fermentation product, especially since the designation of origin “German rum” immediately shows that it was made from German raw material, since no sugar cane grows in Germany, and because designations of origin in connection with the word “rum” are generally commercially available. One could cite numerous other reasons for the permissibility of the designation “German Rum”, but that would be going too far. It should only be mentioned that a whole number of well-known food chemists from different parts of Germany who were asked about the admissibility of the designation unanimously gave an affirmative statement.
[I have never found Herzfeld’s citation from Hubert Von Olbrich’s bibliography:
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]
(9) leitsatze des Vereins Deutscher Nahrungsmittelschemiker von Jahre 1912, Zeitschrift fur Untersuchung der Nahrungs und Genussmittel, Bd. 24, S. 85.
In the foregoing I have contented myself with merely describing the new product of the German fermentation industry in the main outlines. In the framework of this lecture I had to dare to go into the literature about rum in more detail and to make more detailed comparisons with tropical products, as well as to appreciate the possible economic importance of German rum on the basis of statistics.
In the discussion that followed, Dr. Stadlinger warmly describes the statements of Prof. Haupt and describes the production of German rum as an event and a great achievement of the German fermentation industry, and describes the German rum as highly superior to bad foreign rum. Dr. Popp cannot accept that Jamaican rum can be used to describe everything that is made from Jamaican raw molasses. The sugar cane plantation owners would object to this, in Jamaica such a product would have to be called a surrogate rum: if in Germany the product made from sugar beet molasses is called German rum, that is something completely different, because everyone knows that no cane sugar molasses is processed in Germany. The designation German rum therefore says what one can expect from commercial use, so there is nothing wrong with this designation. Efforts to produce a product on a par with Jamaican flavor from other starting materials containing sugar are very old. Attempts made in German East Africa at the time were unsuccessful. Probably the fermentation organisms were not the same. Regarding the German rums, Dr. Popp believes that he is entitled to judge himself to some extent , personally expressing the feeling that the samples are to be considered on par with a good blended rum, maybe, but no with a genuine Jamaica rum, which one smells in the throat for six weeks. [tricky to translate because I think he is saying something poetic about the persistence of Jamaica rum.] That’s why the London Dockrum is only being prepared for the German market. It comes on the market at 75%, but is softened by blending with Arrack. But the German rum shouldn’t be on a par with the Jamaican rum either, it’s a peculiarity. Professor Haupt explains that 3 types of rum are produced in Jamaica, one for the natives, one for the English taste and the German flavored rum. The English rum has more of the character of the Martinique rum, this fine floral product is not equal to the German rum. Mr. Erthiler notes that the organoleptic expert must be the main authority when assessing rum. It was found that the odor of the imported Jamaican rum was unpleasant, so it was blended with arrack. Before the new edition of the food book, the Association of German Food Manufacturers and Traders had contacted the Reich Office of the Interior and asked about the production of rum and arrack in the producing countries. Of particular interest was the question of whether and how rum might be colored, because a number of lawsuits involving the coloring of rum with caramel were pending. According to the information, arrack is made from various raw materials in the country of origin, but rum is made from sugar cane molasses. According to the speaker, German rum should gradually be brought up to the level of Jamaican rum, but it is not right to lie about the German product before it has reached this level of quality with the foreign designation, this discredits the product from the start. Here one falls into the same error as in the German Cognac; only when the decision was made to introduce Charente wines and to distill them in Germany according to the methods customary in the Charents and to store them for 1-2 years did the German Cognac gain success. It should also be pointed out that original Cognac only was so valued and sought after when German cognac appeared. One should try to introduce German rum under a German name for rum.
Even before the war, Dr. Brauer had received such rum products for examination and from the Reich, original rum for comparison, the latter smelled so strongly that they had been considered adulterated. Later Brauer received such rums again, but they were stronger. It was noticeable during the investigation that the last fractions no longer smelled so strongly when tested according to Micko, but the Lusson-Girard numbers were almost the same. The German rum was similar to a rum blend, the aroma was weaker than the original rum. Prof. Becker explains that German rum is the same as cognac and champagne. It is a shame that at the Paris World Fair the French stormed into the packaging room of the German food fair to collect the labels that had fallen off. The French know that they can not ask for brandy for 2 sous [sous being a bygone french currency]. The ban on the designation German Cognac imposed by the peace treaty clearly shows that German production is competitive. When it comes to rum, we have a duty to guide the German people correctly when they are misled: the strong-smelling rum is not the real one. We have to get rid of the thought that stuff must stink. Careful management of the fermentation conditions, which are given by the climate in Jamaica, is necessary. It’s not that hot here, so the development of the fermentation organisms is different; but we have a very well developed fermentation industry that can get used to the subtle working methods in this field as well. It is a blessing if we succeed in educating the people to have better taste and, moreover, no longer carry our money abroad. As far as the question of the designation is concerned, this is a purely mercantile question. —Hofrat Wagner agrees with Ertheiler’s view not to call the product “Deutscher Rum” but to choose a designation similar to that of “Weinbrand” for German cognac. Dr Sieber says that if you choose a label other than German rum, the product is a stillborn child. It would then be impossible to make the public understand that it is rum. In his concluding remarks, Prof. Haupt only answers the question of the designation again. According to a report by an official food chemist, the designation “German rum” is permissible, the product is very similar to real rum and is a pure fermentation product.