Chocolate Production

There are three groups of cacao trees: the Criollos, Forasteros, and Trinitarios. The Criollos produce some of the finest flavors, but are disease prone and low-yielding trees. They account for less than 5% of the world crop. The Forasteros provide full-flavored beans and are high-yielding. They account for most of the world crop. Trinitarios are hybrids of the other two.

On plantations and farms, the cacao pods are opened and their contents exposed. The sweet pulp is fermented for 2-8 days. Fermentation of the pulp is a key step in making chocolate flavorful. Three phases occur during fermentation: First, yeasts convert sugars to alcohols and metabolize some of the acids in the pulp. Next, as the oxygen supply in the pods diminishes, lactic acid bacteria attack the pods. Some of these lactic acid bacteria are the same species found in fermented dairy. Last, acetic acid bacteria consume the alcohol produced by the yeast and convert it into acetic acid. The acetic acid then penetrates into the beans, making the cacao beans less astringent. Digestive enzymes within the beans break down proteins and sucrose, which will later produce more aromatic molecules during roasting. The beans soak in some of the flavor of the fermented pulp, which makes the beans more flavorful.

The beans are dried to about 7% moisture, at which point they are resistant to further microbial spoilage. The beans are cleaned and shipped to manufacturers.

The next step is roasting. Manufacturers roast beans to develop their flavor. The roasting needs of cacao beans are milder than those of coffee beans because cacao has an abundance of reactive amino acids that participate in Maillard browning to generate flavor. Therefore, roasting helps preserve the rich flavors within the beans acquired during fermentation.

The shells and nibs are separated after roasting. The nibs are ground into cocoa liquor. After that, the process varies according to the ultimate product desired. For cocoa powder, the cocoa liquor is pressed to remove the cocoa butter, then pulverized. For chocolate, other ingredients are added to the liquor (sugar, milk, vanilla, etc.) and then subjected to conching-a process of extended agitation and added heat. The physical friction breaks up particles of the other ingredients so that they coat the cocoa butter evenly. It also mellows the strong flavor of cocoa by means of aeration. Volatile compounds present in the cocoa evaporate, including acids and aldehydes. Favorable volatiles, such as pyrazines, furaneol, and maltol, become concentrated. These compounds make up much of the characteristic aromas in chocolate. At the end of conching, cocoa butter and lecithin are added to create the creamy texture of chocolate.

Following conching, the liquid chocolate needs to be tempered. Tempering is a process that involves heating and cooling the liquid chocolate to ensure that cocoa butter crystals stabilize and become uniform in size.
Lastly, chococolate is molded and cooled off.