When we talk about chocolate we say the words “addiction”,”guilty pleasure”, “gluttony”. Speaking of which, did you know that, just as the Mayas, Chuck Palahniuk’s “Damned” little devils used chocolate as a form of currency for exchange of goods and that Hemingway himself was particularly fond of chocolate during his Italian days in the early 1900s?
The cacao comes from a plant that is called Theobroma cacao and is cultivated in warm areas (25°C – 27°C) from the equatorial Central and South America to Africa and Indonesia. (1, 2, 3).
Mayas and Aztechs discovered cocoa far before us europeans and used hot cocoa to prepare therapeutic beverages. Cocoa only reached Europe due to the Spanish arrival in Central America the 15th century.
Most people tend to confuse the terms cacao and cocoa which are not interchangeable and have different meanings.
Cacao is the untreated unroasted bean from the cacao tree that is pressed into powder or as nibs thus removing the cacao butter. Cocoa or cocoa powder looks the same but is roasted at high temperature instead (4).
At the beginning, raw cacao bean is bitter so chocolate manufacturers, in order to develop a fully flavoured product, need to apply different processes to the raw material. Chocolate is therefore the product of a series of steps which include: Fermentation, Roasting, Grinding, Conching and Refinement, Cooling and Tempering.
Fermentation is a microbiological process that produces sweet, fruit, flowery flavour attributes. Microorganisms start growing and fermenting the pulp in warm climate air so it is mostly a spontaneous process that lasts from 2 to 8 days. It is followed by a sun-drying step which is required in order to prevent the growth of undesired microorganisms and moulds. Drying lasts around 10 days.
After fermentation, roasting is necessary in order to harmonizes and develop the flavour pattern of the cacao bean and is conducted at high temperatures (120–160°C) from 30 min to 1 hours.
Following the roasting step, the beans are separated from the shells and the remaining part is what is commonly called nib. The nibs pass through different pressings and they pass from a solid state to a thick dark fluid called “cocoa liquor”. This stage serves to free up the cocoa butter and to grind the beans into very small particles so that the tongue is not able to later detect gritty or grainy texture (1, 4). Grinding produces cocoa beans particles that range between 0.02–0.03 mm. Did you know that the Swiss and the Germans tend to grind the nibs even smaller? No wonder if the texture of their chocolate is so famous!
Since cocoal liquor is quite bitter, astringent and acidic, in order to produce chocolate bars and candy bars, other ingredients are needed such as sugar, vanilla, dry milk solids. Conching has the purpose of mixing the ingredients and further smooth the texture of the final product as well as developing desired flavour and aroma compounds (McGee, 2004). The cocoa butter acts as a lubricant for the added ingredients particles hence producing a creamy pasty product that pleasantly melts in the mouth.
Conching is conducted at temperatures that range between 45°C and 80°C and can last from 8 hours to more than a day.
Conching is not the final step as the mixture needs to be tempered which is the mechanism by which the chocolate gains its typical texture. Tempering is finally carried out by carefully warming and cooling sequential steps at controlled temperatures. It allows the chocolate fat to recrystallize appropriately so that it will have a perfect glossy appearance and an optimum “snap” which is the characteristic sound that the chocolate does when broken and constitutes one of the key quality features a chocolate bar needs to have in order to satisfy the end consumer.
1. McGee H. On Food and Cooking: The Science and Lore of the Kitchen. New York: Charles Scribner’s Sons; 2004.
2. Beckett S. The Science of Chocolate. Cambridge: Royal Society of Chemistry; 2008.
3. Grivetti L.E., Shapiro H.-Y. Chocolate: History, Culture, and Heritage. USA: John Wiley & Sons; 2011.
4. Wolfe D., Shazzie. Naked Chocolate: The Astonishing Truth About the World’s Greatest Food. USA: North Atlantic Books; 2005.