Dark chocolate comes from cocoa beans, which grow in cocoa pods. Once a cocoa pod develops on a tree, it must mature for 5 to 6 months. Cocoa pods are harvested off their trees, usually by hand, using a machete. The pods are split open and their beans removed. The beans and the fruit pulp surrounding them are placed in baskets or large boxes lined with banana leaves and allowed to ferment for 2 to 8 days. This fermentation mellows the beans' bitter flavor and lets the pulp's fruity taste settle into the beans. Then the beans are spread out under the sun and dried. The pulp is removed during the drying process. The dried beans are packed into sacks and shipped to chocolate makers.
Roasting and Nibs
The beans are sorted and cleaned at the chocolate factory. Then they are roasted in revolving drums at between 250 to 350 degrees F for anywhere between 30 minutes to 2 hours to enhance their flavor and color. Their roasting time and temperature depends on their moisture level and type. Roasting also loosens the beans' shells. The roasted beans go into a winnower that blows the loose shells off the beans, and the remaining kernel is broken down into nibs.
The nibs are ground and heated into a thick paste called "chocolate liquor." The cocoa butter is pressed out of the chocolate liquor, leaving behind a "cocoa presscake," which usually becomes cocoa powder. Some manufacturers mix the presscake with vegetable fat and sugar to make low-quality chocolate. Cocoa butter is combined with some chocolate liquor, and sometimes sugar and milk, for higher-quality chocolates. At this point, manufacturers decide whether chocolate will be dark chocolate, which is cocoa butter combined with chocolate liquor, a small amount of sugar and vanilla. In both the U.S. and Europe, dark chocolate must contain at least 35 percent cocoa solids. In the U.S., it must contain less that 12 percent milk product.
Conching and Finishing
The chocolate is then sent through large steel rollers to smooth out its texture, then sent to a conching machine where it is heated and continuously mixed and ground down to further smooth the chocolate and remove any lasting bitter or acidic flavors. Conching can take hours or several days, with higher-quality chocolate taking several days to conch. Then, the chocolate is tempered, or slowly heated then cooled to a certain temperature, so it becomes smooth. Then it is poured into a mold and cooled.