Rum Manufacture by a Jamaica Distiller, 1882

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Just like the last post, this is quite the first hand account of rum making in Jamaica! This is the paper referenced by Percival Greg in 1895 in his paper titled The Jamaica Yeasts:

In a collection of papers from the Demerara Argosy entitled if I remember rightly the “Planters Manual” 1889, there is an very interesting article on “How to make German Rum, by a Jamaica Distiller”. Among other things the author mentions that the liquor throws up a thick golden head, that fermentation is very slow, and that no particular characteristic aroma is produced until after fermentation has been concluded. This corresponds so exactly with the behavior of my No. 18 yeast during fermentation that I am inclined to think that the yeast forming the golden head or “Rum fat” as he describes it, is the one which I call No. 18. The author after stating minutely the methods to be employed in the manufacture of this German Rum, confesses that this recipe is not always attended with successful results, inasmuch as that some estates, trying all they can, never produce German Rum, while other estates produce it without any apparent effort. Very interesting it would have been if the author had stated, which as far as my recollection serves me he did not, how much importance he attached to the presence of this “rum fat” in producing the aroma, and as to whether this characteristic fermentation was absent or at least not permanent in those estates which tried to produce German rum, and failed. There would be nothing startling if this were so. All the most recent researches go to show that the influence exercised by the particular organism active in the fermentation on the flavour of the resulting aroma of the Beer, Wine, or Spirit has up to within recent years been in many cases under-estimated or indeed not taken into account at all.

Well, for starters, Percival Greg, did not have the correct article title, book title or year of publication so it was a bit hard to track down the paper. I had to write letters around the world. And then of course with a few clues, I found out it was published in a second location which had already been found and referenced by Frederick H. Smith in his section on “Jamaica Rum” in the recently published Oxford Companion to Spirits & Cocktails, page 606.

Percival Greg, and his experiments, may also be caught up in a quirk of all this pursuit of rum oil aroma, and that is that there are a few different wants to skin the cat, and sometimes the organisms overlap. All this science was before any awareness of pH. Greg’s pure culture yeast work may have been inadvertently conducted at high pH where a fission yeast is capable of producing rum oil itself whereas this account of German rum production is under the infamous high acid conditions where a fission yeast is likely active but the rum oil may be produced by cellulolytic bacteria (possibly a precursor released to be transformed by someone else), very particular late stage lactic acid bacteria, or even very particular butyric acid bacteria.

As we keeping seeing across the literature, rum making is about the intentionality of unlocking high value bound aroma from sugar cane products. The ideas were also freely available to anyone that could viably execute them or bring them to market as further evidenced by a tell all article on heavy Jamaican rum published in Guyana of all places. The public domain and idea dissemination, also known as the planterly spirit, as Leonard Wray called it, has always been at the heart of rum. Our generation should not be restricted by what anyone tells us our “tradition” is and instead we should react to our present economic conditions (like rum has always done) and today pursue a fine product by any natural means necessary as long as we keep that noble intentionality in mind. As both challenges and more importantly opportunity mount, I think people are coming around to that.

The paper includes the warning that many have tried to duplicate this process and failed while certain others such as Hampden and Long Pond have succeeded “without any apparent effort”. Microbiologists, trying to create a renaissance of these ideas in the 1970’s, described the knowledge of the day as knowing how to start the processes, but not control them. It may be ultra-terroir and/or the absolute deep end of microbiology.


The following is the method pursued on estates making high flavoured or German rum in Jamaica:—

Apparatuses for making an average of 10 puncheons weekly:—
One still of 1000 gallons capacity; one retort for high wines of 300 gallons capacity; one dunder cistern of 3000 gallons, for dunder to fall direct from still; four dunder clarifiers of 500 gallons each, to which dunder is pumped to cool and settle from cistern underneath; these latter receivers are placed sufficiently high for the dunder to gravitate by gutter or pipe to fermenting house. The fermenting house should contain from 15 to 20 ground cisterns of 1000 gallons each, about 5ft. 6in. deep. If the house is in a very damp place, vats above ground may have to be adopted, but the ground cisterns are cooler and preferable, where slow fermentation is an object. Ground cisterns are made of hard-wood plank about 4 inches thick, plain jointed, and well rammed with about 2 feet of stiff clay between. These if well put in and always kept moist will last over fifty years. A molasses receiver of 500 gallons should be placed in a convenient part of the house for distributing these to all the cisterns. It is also advisable to have a couple of shallow skimming receivers of 250 gallons each, in which to cool the hot materials from boiling-house before draining down to fermenting cistern. For the making of flavoured rum the extreme height of still head should not be more than six feet above the level of the surface of wash when still is fully charged.

[They wanted the squattest still possible to minimize any natural reflux. It is incredible that there is 15-20 fermenters per still!]


Sugar making having commenced in the “boiling-house,” all refuse thrown off in cleansing the cane juice such as skimmings and precipitates from the coppers, clarifiers, subsiders, etc., flows in one common gutter direct to the fermenting house. If over 90 degrees temperature they may be allowed to cool to that in the skimmings receivers, then draw down into a cistern set aside for mixing which should be able to hold 2000 gallons and throw nothing away however dirty looking, in receiver. Go on drawing down until the mixing cistern is nearly full and while filling with skimmings get all the finely powdered cane trash obtained from the mill bed and liquor strainers, and throw into the mixing cistern until the contents appear as it were a half solid half liquid mass. Fermentation soon commences and then the distiller may begin “setting up” his wash. This is done as follows—Take 300 gallons from mixing cistern and put in the bottom of each cistern of wash to be set up. If no dunder on hand from last crop add 100 gallons water and sweeten with 10 of molasses; leave this till decided signs of fermentation appear, then add 100 to 150 gallons more water with proportion of molasses and wait a second time for fermentation to show itself and so on until the cistern has been filled. The proportions of materials will then stand thus:—skimmings, 300 gallons; water, 640 gallons; molasses, 60 gallons, and the gravity 6° to 7° by Beaumé’s saccharometer [SG 1.043 to 1.051]. This is light setting and must be pursued until the house is got into good working order, as, to set higher at first, would risk the spoiling of materials. The first round of the house should attenuate down to about water mark, or at least to 1½° Beaumé [SG 1.010]. In the second round, dunder instead of water is to be used, in setting up, and this it will be found will raise the gravity of the wash considerably, although only using the same percentage of sweets as before, as from the fact of certain unfermentable ingredients being held in solution by the wash, the dunder if not reduced would increase in gravity about 3° Beaumé every time it is used [add 0.021 to SG]. In the making of flavoured rums it is allowed to go up to 8° or 9° [SG 1.058 to 1.066] before using water to reduce it. When the house is in good working order the wash is set at from 10½° to 13° B [SG 1.080 to 1.099] with sweets, say, 200 to 300 gallons skimmings and 70 to 75 gallons molasses, will work for 8 or 10 days and attenuate to 5° or 7° B [SG 1.036 to 1.051]. This wash should yield 85 gallons rum at proof strength [57.14% ABV], or about 60 gallons of Jamaica shipping strength [80% ABV]. During the process of fermentation the wash works with a pretty heavy orange-coloured yeasty head called by the negroes the “rum fat,” not by any means an inappropriate term considering that in this is supposed to lie the aroma which enhances the value of the spirit. This yeasty head while remaining on top of cistern rapidly communicates fermentation to other fresh wash, but after a few days it all falls to the bottom in the form of a fine sediment, when it will not again incite the vinous fermentation. When the wash is dead it should be allowed to remain for twenty-four hours before distillation. This is a most important point, and in fact may contain the key to the whole theory of the development of flavour. Although it often happens that during the whole process of fermentation, a slight fruity odour may be found pervading the wash cistern, it is during this period of twenty-four hours that it becomes the most marked, and the cause may be nothing more or less than the setting in of putrefactive fermentation in the precipitated yeast before mentioned. There can be but little doubt that the soil and cultivation are the chief sources of fine flavour, as many estates have from time to time made flavoured rums without any effort whatever, while on others every effort to produce flavour has failed. Still that much may be done to improve and even develop a flavour, hitherto latent perhaps, by the adoption of the fore-described process is as equally incontrovertible. The chief vehicle of flavour is supposed to be the skimmings and other refuse added to the mixing cistern, as rum made with pure sugar or molasses is nearly always devoid of anything like flavour. If, then, there is any probability or possibility of making flavour out of the materials at hand, this method, according to our present lights, is the most effectual. The flavour itself is an essential oil of an extremely volatile nature, and the theory is that this, or whatever may hold it in suspension, requires the action of an acid or acids to make it dissolve, or set it free, and further, that this is effected by the great acidity engendered in the mixing cistern, and afterwards through the period of fermentation of the wash. This acidity, were it not for the re-agent we have in the heavy body of the dunder, would be perfectly ruinous to our returns, as to set up a cistern with pure water instead would only result in a vat of vinegar. It is known that in fermentation there are good and evil acids, and it sometimes happens, when sufficient skill and watchfulness are not bestowed during the process and progress of attenuation, that the acetocis gets the mastery, and all the dunder has to be thrown away and a new start made; but, on the whole, it is found that about as much rum is made under this method as by the ordinary one. Before pumping the dead wash up for the still it should be well stirred up in the cistern, so that as much of the sediment at bottom as possible may go along, and the thick of sediment left by the pump is allowed to remain so as to hatch a flavour (as it were) in the fresh wash to be set up in same cistern.

[That is quite the run on paragraph! For starters, as observed, fission yeasts are known to be switch hitters and the same yeast can move from top fermenter to bottom. There are very few leads on what can drive that behavior. And wow do they add a lot of bagacillo to their mixing vat! It is basically sugar cane saw dust and sometimes pitched into stuck ferments as a corrective. It is thought that it creates a scaffolding for the yeast to grow on. However, theirs may also bring cellulolytic bacteria and possibly even distinct butyric acid bacteria that may be harbored in rat eaten canes. Jamaica in the 19th century had a very significant rat problem, but planters were not overly worried about it because they could make rum from the damaged canes. They were even called rum canes. This butyric acid bacteria may be distinct from others and produce aroma very late in the fermentation where others leave little mark because of challenging growth conditions. Parallel observations may have been made in fancy Barbados molasses and add weight to the idea butyric acid can produce rum oil. It appears that if dunder is taken out of the equation, the desired aroma will not be produced. All of the volatile acidity is not enough to prevent undesirable bacterial ferments that destroy ethanol and do not promote the butyric acid bacteria. One theory I have is that when they thought they were observing acetic acid bacteria they were instead observing lactic acid bacteria that can also produce acetic acid. This LAB is extremely acid tolerant and can keep producing acetic acid until the ferment is stuck (8.0+ g/L VA) and prevents the eventual growth of aroma beneficial butyric acid bacteria. Even though they are making a volatile acid saturated wash, the author claims the dunder can be spoiled. It seems like a challenging skill is to know when you’ve crashed and how to properly start over. We even see beautiful language forming the theory of how aroma must be unlocked or you must “set it free”. You may be tempted to think you could start duplicating a process because of access to bagacillo, but when we read the microbiology between the lines, something simple seeming becomes more complex, featuring multiple roles and options for microbial contribution. There is a lot of potential to decrease risk and increase all of consistency, viability, and efficiency, but progress won’t be made until we can make direct observations of traditional practices.]

[“Rum Fat” from Cory Widmayer using the historic Mellacei fission yeast.]

[A recently isolated fission yeast from Ecuador exhibiting a different expression of “Rum Fat” from Cory Widmayer.]


The ordinary method of manufacture where flavour is not or cannot be obtained is much shorter in detail, and does not require much over half the fermenting room. Dunder is kept at about 5° to 6° Beaumé [SG 1.036 to 1.043], and, wash never set above 8° [SG 1.058]. Fermentation is brisk and sparkling, without any head except large bubbles, and is over in three to four days. For economy of fuel, double instead of single retorts are used in distilling, with wash heaters or chargers through which the still worm passes, acting at the same time as a condenser. By this method there is no double distillation of low wines. The charge consisting of—1st, wash for still, 1000 gallons ; 2nd, low wines for first retort, 150 gallons, 50% under proof [28.57% ABV]; 3rd, high wines for second retort, 70 gallons, 15% o.p [65.71% ABV].

Return = 50 to 65 gallons rum, 40 o.p. [80% ABV]; 65 to 70 gallons high wines, 15 o.p. [65.71% ABV]; 150 gallons low wines, 50 [u].p. [28.57% ABV]

With single retort the charge and return are as follows:—
Charge wash, 1000 gallons; high wines for retort, 80 to 100 gallons.
Return=Rum, 45 to 50 gallons; high wines, 80 to 100 gallons; low wines, 150 to 200 gallons.

The low wines, by the latter method, are put in a butt, and when sufficient they are put in the still and distilled the same as wash, and the rum from this distillation is called low wines rum as distinct from the others called wash rum. The low wines rum having little or no flavour, is usually shipped under a distinguishing mark, and fetches from 6d. to 1s. per gallon less in the market than the wash rum. The proportion of low wines to wash rum is about one-third of the former to two of the latter. It is customary on some estates, after taking off the charge of high wines, to throw the low wines or lees into the next cistern of dead wash to be run. This obviates the running of low wines stills, and makes the rum of equal quality all round; but this method is not much approved of, as the lees are considered to deteriorate the quality of the dunder, and although the whole of the rum may have a flavour, it may just be enough to miss the mark of pleasing the German smeller’s nose, and consign it to the class of an ordinary rum; and rather than risk this, it is better making sure of at least two-thirds ranking high class. The objection to double instead of single retorts for the making of flavoured rums is attributable to the same cause, namely, that of dissipating the flavour over too large a quantity to make it appreciated. The essential oil, constituting the flavour, always comes over in the first 15 to 25 gallons, and it it is wished to make a few puncheons of very superior flavour, it can be done by keeping the first half of returns separate when distilling.

[Spoiling the dunder is a fairly new concept and it mainly comes from inhibitory volatile acids. An astounding amount of distillate is collected to remove these acids and a squat pot still can do it while other still designs cannot. Some of these secondary sort of queen share rums may explain certain marks we saw in the Long Pond Papers such was “ST (white)” produced at 5 puncheons compared to 45 of regular ST and “◊S (white)” produced at 5 puncheons for 40 of regular ◊S.]

To colour the rum, from two to five quarts of burnt sugar are required to 100 gallons. In Jamaica the old plan of carrying away the rum in cans from the open worms is still carried on, and although the Government excise officers have for years been devising plans for the prevention of theft from these exposed can pili, they have not yet adopted the simple one of having lock fast glass safes, such as are used in distilleries at home; and if a few of these could be imported and fixed up at a trifling cost, there is no doubt but they would soon be generally adopted, both for the protection of the proprietor and the revenue.

Vale Royal, Jamaica.

[What we have just read may have been a description of Vale Royal’s VR/W Wedderburn mark which may have finally ended up at Long Pond. In the 20th century, Vale Royal used to make a continental rum which they may have gotten from Georgia when it was absorbed in 1940 but stopped in 1949 after no reported sales during WWII. Vale Royal only produced one Wedderburn mark.]

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