Did you know that one the most important steps in making chocolate taste like chocolate is cocoa bean fermentation?
Cocoa beans grow inside a thick-walled pod surrounded by a sugary pulp that provides nutrients to the beans (seeds). The pulp is made up of about 12% sucrose which gets broken down by microbes, mostly yeasts.
During the harvest, pods are cut down from the tree, opened, and the cocoa beans scooped out by hand. Large mounds or heaps of pulp and beans are built in order to start the fermentation process. To speed things along, big leaves (like banana) are used to cover the heaps in order to seal in the heat generated by the microbial action.
The temperature can reach 40C to 50C in the fermentation heap. Many chemical reactions take place, and it is here during fermentation that chocolate acquires its color and flavor.
While the yeasts break down the sugar, ethyl alcohol and heat is produced. Then, both the alcohol and the heat kills the yeast. The heap has to be stirred and turned in order to aerate it and eventually stop the fermentation. The whole process takes about 5 days. Fermenting any longer than 5 days and the microbes will begin to attack the beans instead of the pulp. Over-fermentation can result in creating off-flavors and odors in the cocoa beans.
The beans are dried thoroughly in the sun after fermentation to drive off all moisture and prevent further chemical and microbial activity. At this time, the flavors are locked in and ready for transporting to the manufacturer for roasting, grinding, and making into chocolate coatings and bars.
