As with any cultivation process, there are many dificulties on the way towards a perfect result. When the cacao producer has managed to avoid dangers like foul weather and deseases, harvested the pods and opened them correctly s/he is in a real hurry because now the beans have to be fermented. Of all the bits of the road towards a high quality cacao and later chocolate the fermentation might be the most important. If you don't ferment, or do it badly, there is no turning back. Without fermentation, the beans does not give the chocolate taste and are, basically, useless (even if they are used by some to replace fermened ones to lower the price).
Fermented cacao beans
To ferment the cacao, the producers that we buy from, places fifty to a few hundred kilos of cacao, with the pulp, in a wooden box with wooden lids. There it stays for a few day before it is moved to another, similar box that is placed a few decimeter lower. By moving the cacao beans, they are turned (for equal fermentation) and aerated. After one to three days they are moved to a third and last box, placed even lower than the second. By placing the boxes in different heights a the cacao is fermented in a lower temperature and in air with less carbon dioxide loss towards the end of the fermentation process.
What happens during the fermentation is basically two different things. The pulp is being fermented (the cacao beans is actually not, but we leave it at that to not get too technical) and thus gives heat to the bean. From the bean, through the skin escapes a variety of liquids and moisture until the bean is optimally dry at seven percentages of moist.