When harvested, cocoa beans are recovered from the pod and enveloped by a pulp that needs to be removed.
Then cocoa is fermented and over the course of five days, the fermentation process induces biochemical changes in the beans. The rich aroma develop, and the beans change from purple to chocolate brown. If the cocoa is under-fermented then the beans retain bitter flavors and appear slaty or purple in color.
Purple bean produce bitter and astringent flavors. However they are not usually classified as defective because there is a wide range in degrees of purple color and it is appreciate to define the various category precisely.
Unfermented cocoa has a lower value compared with fermented beans. The precursor to the chocolate flavor are not formed and such cocoa has limited uses.
The industry standard for well fermented cocoa beans is 85%, measured by sampling 20 bean from sack and finding that more than 17 are not purple.
Cocoa bean quality - purple beans
