254 The Fermentation of Cacao 



the acids are then for the greater part oxidized 

 into water and carbonic acid. If wrongly 

 conducted the process leads to the production 

 of fermentation by-products (lactic acid fer- 

 mentation, butyric acid fermentation), which 

 have an unfavourable influence on the value of 

 the product. A considerable variety of micro- 

 organisms take part in the fermentation ; both 

 yeasts (mycoderma, torula, monilia, saccharo- 

 myces) and bacteria, of which the acetic acid 

 bacillus plays a particularly important role. 

 Preyer 1 isolated a yeast, Saccharomyces theo- 

 bromce, from fermenting cacao, and has recom- 

 mended the use of the pure culture of this for 

 the initiation of the fermentation. This idea has 

 been repeatedly exploited. Not much success 

 is, however, to be expected from the use of pure 

 strains of yeasts. The first essential to success 

 is lacking, that is, the possibility of sterilizing 

 the culture medium, for with the death of the 

 germs the destruction of the enzymes would 

 be associated, whose action, as we shall see, is 

 irreplaceable. Without sterilization, pure yeast 

 cultures have but little prospect of competing 

 with wild ones. It often takes some hours 

 before the contents of the broken cacao pods 

 reach the fermenting station, and, in the mean- 

 time, the wild flora, consisting of yeasts and 

 bacteria, has already started the fermentation. 

 Now the processes taking place in the 

 interior of the bean are only indirectly con- 



1 Tvopenpflanzer, 1901, 5. Jabrgang, p. 151. 



