Lots of people ask about cocoa bean fermentation, what is it and why is it necessary…. In short, fermentation is a very complex process, involving microbial activity acting on the cocoa pulp, changes in the internal cell structure and chemistry of the bean, and changes in the internal colour of the bean. The temperature and acidity generated in fermentation kills the cocoa bean, and the process is critical for chocolate manufacturers as it generates the precursors for cocoa flavour (when the beans are roasted). Although the chemistry is complex, the process on the farm is very simple, just making a heap of beans and covering with banana leaves.
Cocoa (Cacao) fermentation is critical to develop the precursors for cocoa flavour, brought out when the beans are roasted. During the process, there is lots of microbial activity, the pulp surrounding the beans drains away, acid is generated, the fermentation heap gets warm and the cocoa beans begin to germinate but are stopped by the acidity and heat. Fermented beans are no longer viable as seeds and won’t grow into new cocoa trees, but when they are roasted and processed they form the main flavour component for chocolate. Here’s two ways to ferment beans – in a heap on the ground (usually covered in banana leaves), or in a wooden box. Both work, but give slightly different flavour profiles in the resulting cocoa.