FERMENTATION 575 



when prepared from pure sugar or glucose, and when care is taken to prevent 

 local superheating, is highly soluble in water and to a less degree in spirit. 

 There are present, however, especially when the decomposition is pushed to 

 extremes, caramels which are insoluble in water and soluble in spirit. If 

 these are present in any notable quantity, a perfectly clear 40 O.P. spirit 

 may give a deposit when mixed with water, and to the presence of these 

 caramels is to be attributed one of the causes of faultiness in rum. 



Caramel produced by burning sugar is completely soluble in water in the 

 presence of alkalies, and the solution at the same time assumes a much darker 

 colour ; but caramels dissolved in spirit are precipitated by alkalies, the 

 solution becoming less coloured. In the presence of alkalies the flavour of 

 the caramel undergoes a complete change, and at the same time gives off 

 a peculiar odour. 



A process which was long kept a trade secret and used, it has been stated, 

 especially for colouring rums, consisted in burning sugar in the presence of 

 alkalies ; the proportions used were 60 parts of sugar and 2 parts of sodium 

 carbonate or 1-5 parts of caustic soda. This process is referred to as 

 Asrymusry's, and is used to some extent in the West Indies. 



When caramel is used for colouring rum, two points have to be con- 

 sidered. The caramel should reduce the strength of the spirit as little as 

 possible, and should give to the rum a sugary flavour. To obtain the latter 

 effect the molasses or sugar syrup should not be burned too far, but in this 

 case the amount of caramel required to give the necessary depth of colour 

 so much increases the density of the spirit that there is a large apparent loss. 



The usual method of preparing caramel is as under : Into an iron pot of 

 about 200 gallons capacity, usually an old iron tayche, are introduced 40 

 to 50 gallons of molasses, with or without the addition of alkalies as indicated 

 above. Water is added to reduce the density to about 1-25. A brick 

 oven is built under the pot, and a brisk fire kept up. The molasses or syrup 

 must be kept in continual motion, preferably by a mechanical stirrer. The 

 sugar solution rapidly darkens, and in from 60 to 90 minutes is quite black. 

 The usual test to show if the caramel is sufficiently burned is to remove 

 a portion on a stick, and, after cooling, to break the caramel with the finger ; 

 it should be quite brittle. Another test is to drop a globule of the burnt 

 caramel into water, the floating of the globule being an indication that the 

 caramel is sufficiently burned. When either of these tests obtains, the cara- 

 mel will colour rum reasonably well, but to obtain a low obscuration the 

 burning must be continued longer. When the point at which the caramel 

 is sufficiently burned is decided, the fire is drawn and sufficient water added 

 to permit of easy carriage to the rum store. 



The higher the temperature at which the caramel is burned, the less is 

 required to produce the necessary depth of colour, and the apparent loss of 

 strength is lower ; the after-treatment in the rum store has also an effect on 

 the caramel. If the crude colour be repeatedly treated with strong 60 O.P. to 

 70 O.P. spirit, the coloured solution allowed to settle, and the clear colour 

 drawn off, eventually a colour is obtained which gives a barely appreciable 

 obscuration. This process is too lengthy to carry out in practice, but a 

 colour burnt as described above and treated once, bulk for bulk, with white 

 rum from the still, will give a fully coloured rum with apparent strength, 

 as shown by the Sikes hydrometer, only from one or two proof degrees less 

 than the actual. 



In the West Indies first molasses are generally used to prepare caramel, 



