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This appeared as a Commerce Report but was also reprinted in Pure Products, 1917. Somehow this escaped Kervegant’s bibliography.
“As a rule no sulphuric acid is added” [to Barbados rum…], very interesting. A lot of the language choices center around proving the products are pure and free of unacceptable additives. I’m betting that those Barbados rums were only washes that were sent to their pot stills and that washes for Stades’ continuous column still did use sulfuric acid.
Jamaica rum puts a big emphasis on sugar-cane inputs other than molasses; “skimmings, rum cane juice, or normal cane juice”. The idea is also presented that the acids come from sources other than direct conversion of sugar. This would include ethanol transformed into acetic acid by acetobacter as well as lactic acid transformed into butyric acid by bacteria. Fission yeasts are mentioned twice in the Jamaica section. Not enough contemporary attention has been given to Jamaica’s use of non-molasses ingredients other than dunder for its heavy rums.
The Martinique section mentions the use of lime as well as curiously the use of bagasse, the context of which implies it was a feature of fermentations.
I used the version from Pure Products and only found the Commerce Report later.
Poor Trinidad, very boring, and held back by the colonizers. Trinidad was always afraid of “bush rum” production which was a tradition descended from the original Buffalo soldiers who came from America (If I created a new production in Trinidad, I would explore “rule of thumb distilling” and that tradition).
Manufacture of Rum in the West Indies
(The following article as compiled by Consul C. Ludlow Livingston, Barbados; Vice-Consul Frederick L. Herron, Santiago, Cuba; Consul J.C. Monaghan, Kingston, Jamaica; Consul T.R. Wallace, Fort de France, Martinique, and Consul Andrew J. McConnico, Trinidad, on the manufacture of rum will interest the general reader and also be of value to the technical man who is desirous of a descriptive treatment on the subject.— Ed.)
Barbados.
The rum-distillation industry of Barbados is growing in importance, due to the introduction of improved stills, increased cane crops, and a larger demand for the product. Barbados rum is considered superior to Demerara rum and, by many, fully equal in quality to Jamaica rum.
The manufacturing methods differ in some respects from the processes used in Jamaica and Demerara. Two factories are devoted exclusively to the distillation of rum and two plantations produce rum in addition to the extraction of the cane juice. One of the factories is equipped with continuous stills; the other factory and the two plantations use the pot stills.
Barbados rum is made entirely from molasses. Vacuum pan molasses is used, without the addition of washings, bottoms from the clarifiers, or skimmings from the cleaning of the cane juice.
The “wash”, consisting of vacuum-pan molasses and water, is set in large vats where it is allowed to ferment without the aid of yeast, and as a rule no sulphuric acid is added to accelerate fermentation. In this respect the process differs radically from both the Jamaica and Demerara processes. The period of fermentation extends to about seven days. As sulphuric acid or sulphate of ammonia is not used, strict cleanliness is necessary to avoid the formation of putrefactive bacteria.
In the local practice there is no material deviation from the usual methods followed with pot stills. The “wash” is heated to boil off the alcohol, the weak spirit from a prior distillation is placed in the retort, into which the vapor from the “wash” passes, and the vapor from the retort passes to a rectifier where it is partially condensed, the strong vapor passing on to a condensing coil in which that from the rectifier is condensed.
The continuous still used in one of the factories is of German manufacture. In this factory the “fusel oil” is entirely removed from the rum by a special apparatus and sold as a by-product. In the other factory the fusel oil is removed by a second distillation and lost in its volatile form.
As the rum comes from the distilleries it is not artificially flavored and is uncolored. Local dealers flavor the rum by the addition of prunes, and coloring is given by storing in burnt casks, usually old port casks, which also impart a flavor to the contents. Occasionally coloring is secured by adding burnt molasses, but this is done only in emergencies when there is not time to employ the burnt-cask method. Different rums range from the colorless liquid to rum darker than a rich sherry.
Barbados rum is usually exported to Great Britain at 64 or 65 over proof [93-94%ABV], proof being 57 parts of alcohol to 43 parts of water by volume. There is no difference between the rum exported to Great Britain or other countries and that consumed locally, except in the matter of flavoring and proof.
In 1915, 185,952 proof gallons of rum were manufactured in Barbados, a decrease of nearly 50,000 gallons compared with the preceding year. There were 33,883 proof gallons of locally made rum exported to other countries out of bond, and 654 proof gallons issued as ships’ stores in 1915. The total quantity exported in 1914 was only 6,704 proof gallons, all going to the other islands of the West Indies, while in 1915, 22,803 proof gallons of Barbados rum were exported to Great Britain, an entirely new market for this product, probably due to war conditions
Cuba.— In all sugar plantations, or centrals as they are called in Cuba, there always remains a part of the molasses produced from cane syrup which can not be hardened and converted into sugar. This residue is fermented in tanks, by adding wheat flour for from 8 to 15 days. After fermentation this compound is transferred to a distillery and sugar-cane alcohol is produced at a grade of 78 to 80 centesimal degrees or its equivalent in Cartier of 30 or 32 degrees. From 3,000 gallons of sugar cane molasses about 690 gallons of alcohol are usually obtained.
Before making use of the alcohol for refined rum, it is allowed to ripen about three or more years. Then the pure liquid is run into serpentine brass coils of a rectifier and after passing through a current of water, which cools the vapors, absolutely pure alcohol is obtained. While in the rectifier the liquid often is carried as high as 97 or 99 centesimal degrees, equivalent in Cartier to 42 or 43 degrees.
When this process is finished, the alcohol is mixed with filtered water to reduce it to 54 degrees and this mixture is then passed two or three times through a series of special filters. These filters are hogsheads made of hardwood, with a capacity of about 900 liters, and each manufacturer keeps a supply according to his output.
The filter is made with a double bottom 5 inches apart. The one on top is full of holes and covered with a thick cloth which constitutes the filtering apparatus. Washed sand, so clean that when thrown into a glass of water the glass and water will remain clear, is first placed in the filter. This layer of sand is about 5 inches thick. On top of this is placed sterilized vegetable coal with a very small portion of animal coal, both being in powdered form.
The wood from which the vegetable coal is produced must be of a certain kind and is very carefully selected.
When the filters are prepared in this manner the liquid alcohol is placed in them and allowed to stand 15 or 20 days to cure itself.
After passing through these filters two or three times the rum is placed in receptacles made of oak and having a capacity of from 4,000 to 5,000 liters and is allowed to settle four to six months. Burnt sugar is used for coloring the rum.
Jamaica.— “Jamaica rum” is the generic name of the several varieties of sugar-cane spirit that are manufactured or distilled on the island of Jamaica, the only materials used being the products of the sugar-cane.
There are two general methods of manufacture, in the first of which the whole juice of the cane as received from the mill is evaporated down and set up with dunder, which is the residue from previous distillation, to a gravity of 16 Brix. Spontaneous fermentation is by a fission yeast and the wash dies down in about three days. In the second general type of manufacture the molasses, skimmings, and other offal of sugar manufacture are set up with the dunder to a gravity of from 16 to 18 Brix. Here, too, spontaneous fermentation is by a fission yeast and the wash dies down in from three to five days.
In the distillation of Jamaica rum a pot still is used with two retorts. In a still containing 1,000 gallons of dead wash, with 200 gallons of low wines from previous distillation at 50 under proof [28% ABV], in the first retort, and 75 gallons charged with 60 to 70 gallons of high wines from previous distillation at 6 over proof [60% ABV], in the second retort, it is possible to obtain from 70 to 90 gallons of rum at 40 over proof. The stills used in making this rum are heated either by steam coils or by direct fire.
Jamaica rum is generally colored with a caramel, obtained by heating the sugar in a copper vessel and extracting it with a strong rum. If well burnt, the obscuration is very small and should not exceed 1 per cent proof spirit.
After distillation, the rum is put up in puncheons holding from 100 to 108 imperial gallons, or about 120 to 128 American gallons. It is generally sold at 37 overproof in the puncheon, the original strength of 40 overproof going down in the wood. No credit is given, commercially for overproof rum.
The two principal kinds of Jamaica rum are the “common clean rum” and the “German” or “flavored rum”. The “common clean rum”, depending upon the materials used, may be divided into two classes, “local trade quality” and “home trade quality”. The “local trade quality” is a light rum produced chiefly in the parish of St. Catherine and in the District of Vere, in the southern part of the island. It is distilled from a wash set up of skimmings, molasses, dunder, and water. It has been said that the most sensitive barometer of the material prosperity of Jamaica is to be found in the returns of the duties on this “local trade quality” of rum. This is the grade sold in the rum shops all over the island to the natives, and it is chiefly distilled for home consumption. For the year ended June 30, 1916, about $550,000 was paid in local internal revenue taxes on the distillation of Jamaica rum.
“Home trade quality rum” or “public house rum” as it is sometimes known, is that distilled principally for consumption in the United Kingdom. The bulk of the rum exported from Jamaica is of this grade. It is made from washings set up from the same materials as the “local trade quality” to which is added, however, an acid prepared either from skimmings, rum cane juice, or normal cane juice. The composition of the wash varies to some extent, but it usually consists of skimmings (fresh) about one-third; dunder, one-half to one-third; acid, one-tenth to one-third; molasses, one-fifteenth to one-tenth; and water.
The fermenting cisterns, sunk in the floor of the distillery, built of wood and backed by puddled clay, and vats, are usually of 1,200 gallons capacity. The still will receive the contents of one cistern, and two stills are usually run per day. They are heated either by steam coil or by direct fire. The rums made with “common clean” materials vary in their ether content from under 100 parts to over 1,000 parts. Acetic ether is practically the only one present, and its amount depends entirely on the quantity of the acid used in the washes and on the length of time the wash ferments and lies dead.
The best grades for the “home-trade” market are made in the Parish of Westmoreland, while some very fine rums are also produced in Clarendon, St James, and Trelawney. All of these are characterized by a high standard of heavy residual body, mainly ethers of acids having high molecular weight. These acids are not producible from sugar and are almost absent from rums, other than Jamaica, which are produced from diluted molasses, without dunder or acid skimmings, and distilled in patent stills. Experiments show that these higher acids result from bacterial decomposition of the dead yeasts found in the distillery materials in Jamaica, and it is the belief of the chief of the local Government chemists that the adherent yeasts in the old ground cisterns have a good deal to do with the fine flavor of many of the “home-trade” rums. As compared with the “local-trade” rums, it has been noted that they have a stouter, fuller, and more fruity aroma, and that when broken down with water the spicy residual flavor is strongly marked.
Martinique.—The four principal methods employed in Martinique for making rum are: First, by distillation of molasses; second, by distillation of cane juice heated and reduced to 30° Baumé; third, by distillation of cane juice heated and concentrated to 18° Baumé, on an average; and fourth, by distilling the pure cane juice, not heated. The molasses from which rum is distilled in Martinique is the residue of the condensed juice after the sugar has been extracted. The analysis of a sample shows the following percentages: Baumé, 37.86; density, 1,438; sugar, 38.34; glucose, 26.14; cendres, 4.97; salins, 7.60; purity 46.09; water, 16.05; organic matter, 12.29; and acidity, 0.35;
The juice from which the molasses is obtained is first purified and a certain quantity of albuminoid matter contained in it is separated. It is also limed, an operation which has great importance in the distillation.
Before the molasses is fermented it is mixed with water and venasse in proportions adopted by the different centrals in order to obtain a mixture of small density and most easily fermented. The use of the venasse has an important effect on the flavor of the rums. The venasse is the substance remaining in the still after the spirits and most of the water have been evaporated.
The flavors held by the different substances of which the venasse is composed are difficult to extract and when it is used in later distillations a large percentage of the flavors remaining will be recovered. It also has an indirect effect by improving and making the fermentation regular.
After the different materials have been mixed the compound is sent to the vat to be fermented. There are two methods employed. First, by the use of pure ferments by which method fermentation requiring from one to four days for completion is obtained. The yield of alcohol is usually good by this method. Second, the liquid to be fermented is ex posed to the air from 6 to 14 days. This method is often imperfect in the results as to the yield of alcohol; nevertheless it has been employed in the centrals which prefer to keep the same flavor for their products.
The method of distillation ordinarily employed in Martinique is the continuous distilling apparatus, very few of the intermittent types being used.
After distillation the rum is sent to the vats from which it is distributed into barrels and colored with caramel.
The difference between rum made from cane juice heated and concentrated to 30° Baumé and that made from molasses is that the raw material from which it is made is much purer, a sample analyzed showing the following: Baumé, 26.30; sugar, 40.45; glucose, 8.20; and purity, 74.93.
The degree of purity in this analysis is 74.93, while for the sample of molasses analyzed it was 46.09. The product distilled, however, will be less rich in foreign materials; the alcohol being purer the flavor will not be so strong.
The process of condensing, fermenting and distilling from syrup is the same as for molasses. The compound is made in the same manner by means of water and vinasse; but to obtain a determinate density for the mixture, these two products are added in smaller, proportion as the product is already of a less density than that of the molasses.
The quality of rum made from cane juice heated and concentrated to 18° Baumé is intermediary between that made with molasses or syrup and rum habitant (Grappe Blanche) made by distilling cane juice with out being heated.
The cane juice is extracted by single or double pressure at the mills. It is sifted and then sent to be heated and limed, these operations taking place in the same reservoir. The juice is then conducted to the settling pans, decanted and sent to the evaporator. Sometimes the evaporation is made in pans by direct heat or by an evaporating apparatus or boiler especially designed for the purpose, which may consist of one or more boilers heated by steam. The mixture is then treated as above described, fermented, and distilled.
In rum distilled from the pure cane juice, not heated, the juice is extracted in the same manner and is immediately prepared for fermentation. If the juice of the cane has a density superior to 8° or 9° Baumé, water and venasse is added to obtain the required density. The mixture resulting is not sufficiently rich in azot to be able to feed the ferment, and to obtain a good fermentation from 200 to 400 grams sulphate of ammonia is added to 4,000 liters of juice and ½ or 1 liter of sulphuric acid to 4,000 liters of juice. It is distilled in the same manner as the mixture for molasses.
The French Government requisitions 50 per cent. of all the rum produced by distillers who make over 40,000 liters annually. The exportation of rum to foreign countries from Martinique is prohibited; all exportations must go to France.
The degree is calculated at a temperature of 15° C., the standard fixed by law for rum being 60° alcohol at this temperature. The temperature of Martinique being higher, the alcometer must show 65° to meet the requirements.
Trinidad.— The manufacture of rum in the colony of Trinidad and Tobago is conducted on scientific principles under the strictest Governmental supervision. Sugar production was the chief industry of the colony for many years during the nineteenth century and it was not until about 1860 that centrals began to be established in the larger cane-growing sections. Prior to this time each estate owner manufactured his own sugar by means of open pans or kettles, and rum as a byproduct was produced from the residue of molasses, scum, dunder, and megass [bagasse]. At that time the old pot still was used, but with the advent of the centrals patent stills were adopted and the facilities for converting molasses into rum were greatly increased.
At present, owing to Governmental regulations and stricter excise supervision placing the minimum capacity of stills at 400 gallons, the smaller manufacturers have been eliminated and there are but four distilleries in the colony. These vary in capacity from 700 to 1,500 gallons, the largest distillery making use of the Coffey still, the other three of continuous stills.
Great impetus was given to the manufacture of rum by the outbreak of the European war. Before the war most of the rum manufactured was consumed locally, although for certain years the records show that the quantity exported almost equalled that consumed locally.
Rum exports from Trinidad for the years 1912 to 1915, inclusive, were as follows: 1912, 85,888 gallons, valued at $41,305; 1913, 102,323 gallons, valued at $51,793; 1914, 174,657 gallons, valued at $86,561 and in 1915, 915,589 gallons, valued at $418,514. The quantities given are in imperial gallons, 1 imperial gallon being equal to 1.2003 United States gallons.
The collector of customs states in his report for 1915 that 306,937 proof gallons, valued at $264,156 were consumed locally; and that 912,810 gallons, or 99.4 per cent. of the total quantity exported, valued at $416,108, were sent to the United Kingdom.
All rum is drawn under the supervision of revenue officers and must be stored in bonded warehouses. When withdrawn for local consumption an excise duty of $2.28 per proof gallon is exacted; when exported, an exportation bond. The import duty on rum from British Guiana and the British West Indies is $2.40 per gallon; from other parts of the world $3.12 per gallon. Owing to the superior quality of the locally manufactured product and the high import duty on foreign rum the quantity imported is negligible.
Trinidad rum, like that of Demerara, is made almost exclusively from vacuum pan molasses. Its ether content is also low. No difference exists between that exported and locally consumed, the strength of all being 40 over proof, or 75 per cent. alcohol by volume.
It requires on an average 2½ gallons of molasses to produce 1 gallon of rum 40 over proof, or 75 per cent. alcohol; with rich molasses, about 2¼ gallons.
When cane juice is used, sugar is sacrificed to the exigencies of rum manufacture. It requires from 11 to 12 tons of cane to produce 100 imperial gallons of rum 40 over proof, or 75 per cent. alcohol, practically the same quantity of cane as would give 1 ton of sugar. This conversion of cane juice into rum pays only when war prices for rum obtain. It has been stated that during the 1915-16 season approximately 20,000 tons of cane were consumed in the manufacture of rum. However, in normal times vacuum pan molasses is the principal ingredient.
No flavoring substances are used by the local distillers, but all rum for export is colored with burnt sugar; that is, by converting the sucrose of the molasses into caramels by burning. When rum is taken from the bonded warehouse for local consumption it is colorless, but before it reaches the consumer it is colored with burnt sugar and sometimes flavored with prunes and raisins. Before the addition of coloring matter the specific gravity gives a close indication of the percentage of spirit present; but after it is added some of the alcohol is obscured by the color, and the proportion so obscured is termed obscuration of the spirit. For instance, most local rum 40 over proof after being colored shows only 38½ over proof, thus confirming the statement often made that when coloring matter enters into the composition of rum its strength can not accurately be determined by the hydrometer.