124 COCOA FERMENTATION 



acteristic brown or chocolate colour is only present in 

 the external portions of the bean, and if a bean is cut 

 it wiU be found to have retained its original colour in the 

 centre ; complete coloration is not effected until the 

 beans have been dried. 



If cocoa beans, freshly taken from their fruit-sheUs, are 

 placed in a heap and the temperature of the mass registered, 

 it will usually be found that the temperature of the heap 

 Avill commence to rise in an hour or two, and may continue 

 to rise, if the beans be left undisturbed, for seven or eight 

 days. At the end of this period there may be a difference 

 of 50° Fahr. from the original temperature of the heap. 

 The rate at which the temperature will rise and the 

 extent of the rise will vary, within certain limits, in 

 proportion to the size of the heap, the air temperature, 

 and the amount of humidity in the atmosphere. With 

 the increase of temperature liquid matter oozes from 

 the heap owing to the decomposition of the pulpy envelope 

 of the beans. The first exudations have a sweet fruity 

 odour, the later a vinous and then an acetic acid odour. 

 Provided that the temperature of the heap has not 

 exceeded 140° Fahr., the beans Avill not be injured from 

 a commercial standpoint. The sugary pulp wiU be 

 found to have shrunk to a considerable extent and the 

 remainder can be easily washed off. The beans have 

 now been fermented. 



Yeasts and Bacteria. — Preyer {Tropenpflanzer, pp. 

 151-173, April 1901), who studied the fermentation of 

 cocoa in Ceylon, states that Saccharomyces Theobromce, 

 a yeast, produces the best fermentation in Ceylon, and 

 mentions that S. cerevisicB, and a species similar to S. 

 elUpsoides, 8. memiranoBfaciens, as well as a mould, 

 Penicillium sp., have been found by him in fermenting 

 cocoa in that island. He successfully bred pure cultures 

 of the organisms associated with the fermentation of 

 cocoa. Lutz found, in addition to 8. TheobromcB, 

 8ierigmatocystis nigra, Psevdo-Absidia vulgaris, and a new 

 fungus, Fusarium Theobromce, Lutz. 



Harrison has also investigated this subject in British 

 Guiana. He considers that the process of fermentation 

 or "sweating" in cocoa consists in an alcoholic fermenta 

 tion of the sugars in the pulp of the fruit, accompanied 

 by a loss of some of the albuminoid and indeterminate 



