568 CHAPTER XXVIII 



Islands, the French West Indies, Hayti, and the Argentine. Rum is also 

 manufactured in connection with sugar mills in Peru, Mauritius, Queensland, 

 and Natal. Molasses forms the source of the spirit " arrack " in Java, and 

 is also utilized in British India ; in these two localities, however, the 

 manufacture of spirit is divorced from the sugar industry proper. The 

 writer has been unable to obtain statistics of the annual production of rum, 

 but believes the total production cannot be less than 20,000,000 gallons 

 of spirit containing 75 per cent, of alcohol. 



The fermentation processes under which rum is eventually produced are 

 very complex, and differ largely from locality to locality. Probably the 

 most general agents are the budding yeasts which have been described earlier 

 in this chapter. To these is almost entirely due the rum made by the 

 quick fermentation process, as followed in British Guiana for example, 

 where the fermentation from start to finish only lasts forty-eight hours. 

 The second most important agents are the fission yeasts, which do not seem 

 to be of such general occurrence as the budding type. Thirdly, there is 

 the influence of the non-sporing yeasts, torulae, etc. ; and finally there 

 is the part played by bacteria, especially of the butyric-acid forming type, 

 which appear principalh'^ in the slow fermentation processes in use in 

 Jamaica, where the fermentation lasts as long as two weeks. 



Outlines of the processes used in different localities follow. 



Demerara. — A process of adventitious fermentation obtains ; com- 

 mercially exhausted molasses forms the initial product ; the molasses are 

 received directly from the centrifugals, storage for a few days' supply only 

 being provided. The molasses and water — generally trench water — are 

 usually mixed to the required density in a mechanical mixer in the basement 

 and pumped up to the vats in the fermenting loft ; in other cases the mol- 

 asses is pumped up to the vat and mixed by hand with the requisite amount 

 of water. The density of the mixture varies from i-o6o to 1-063. To 

 the wash is added sulphuric acid, and sulphate of ammonia in the proportions 

 of I gallon and 10 lbs. per 1000 gallons ; the acid is added to prevent the 

 growth of bacteria, especially the " butyric acid " form. Fermentation sets 

 in rapidly, and is generally complete in 48 hours ; the density of the fermented 

 wash varies from 1-015 to 1-025, and is governed by the amount of sugar 

 present, and by the action of the j^east. In some distilleries, ammonium 

 bifluoride is used as a bactericide in place of sulphuric acid. 



Bird, in Demerara, has quite recently shown that better results are 

 obtained by transferring yeast from an actively fermenting vat to one just 

 set up. As a means of doing this he places a cask within the vat, the 

 contents of the former serving to " pitch " the next lot of wash in that 

 vat. 



Mauritius. — In this district only one sugar factory possesses or did possess 

 (1901) a distillery as an annexe. The process there followed is as under: — A 

 barrel of about 50 gallons capacity is partly filled with molasses and water of 

 density i*io and allowed to ferment spontaneousl}' ; sometimes a handful 

 of oats or rice is placed in this as a preliminary to fermentation. When 

 attenuation is nearly complete, more molasses is added until the contents of 

 the cask are again of density i-io, then again allowed to ferment. This 

 process is repeated a third time ; the contents of the barrel are then distri- 



