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 rdle. 
Preyer’ isolated a yeast, Saccharomyces theo- 
brome, 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 Tropenpflanzer, 1901, 5. Jahrgang, p. 151. 
