For the Love of Chocolate

A Short History

The art of making chocolate is chemistry exemplified. Historians traced the origins of chocolate 4000 years ago to a small village in Honduras, where it is believed the first hot chocolate drink, Xocolati, or bitter water was made. Cacao beans remained a prized, native possession in Central American cultures for 2000 years before becoming introduced in Europe around 1500 AD.

Even so, chocolates did not become affordable for the middle-class until sugar and cocoa prices had dropped enormously around 1900AD. Also, the liberalization of the cocoa trade and the elimination of government taxes on cocoa beans led to a growing commercialization of chocolate. In Italy, Francesco Buitoni of the ‘Buitoni’ pasta making family, started developing small chocolates wrapped in silver paper and called them baci, which means “kisses”, in Italian, and the connection between love and chocolates was initiated. Callebaut chocolates, a famous Belgian chocolaterie, started selling in bulk to bakers and chefs and mainstream use of chocolates as a food item became commonplace.

Roasting is Key

The process of making chocolate from cocoa beans is saturated with chemical reactions. About 600 types of chemicals such as alcohols, carboxylic acids, aldehydes, ketones, esters, and pyrazines have been identified as flavor and smell components of chocolates. Depending on the type of bean selected, chocolates can have over two hundred flavor compounds. At the early stage of the processing, during fermentation, a class of volatile nitrogen containing chemicals known as pyrazines is formed which add a distinct peppery flavor to the beans.

Next, the beans get ready for roasting. The roasting process constitutes of a chemical reaction known as the Maillard reaction. Maillard reaction is a complex set of chemical reactions that food chemists and chefs use to bring out flavors of their ingredients during roasting. The reaction occurs between amino groups of proteins and the carbonyl groups of natural sugars and is famous in the food science industry. Applying dry heat starts the reaction. This technique can be controlled by time, temperature, and pH. The Maillard reaction conditions are often ardently guarded by famous chocolatiers. “Dutching” or alkalizing, and a final heat treatment to remove by-products seals in the flavor of chocolates.

Many Forms of Chocolate

So what makes eating chocolates a delicious and melt in your mouth experience? The taste of chocolate depends on the structure of the cocoa butter. It turns out that there are six different crystalline forms (I-VI) of cocoa butter that emerges during chocolate making as the butter solidifies into hard chocolate. The higher forms have more densely packed chains (it’s a lipid), are more stable, snaps when broken, looks glossier, and tastes creamy. Form V is the most superior in taste and structure and sought after by most specialty chocolatiers. When the chocolate melts in a hot car, for instance, it hardens into a different texture and taste. Chocolate V can slowly change into another form of chocolate if stored it at room temperature for a few months. Cocoa butter is pricey; many candy bars try to achieve the same feel by using emulsifiers such as lecithin to retain the melt in the mouth experience.

So the lesson here is to eat chocolates immediately upon receiving or buying them. No chewing necessary! By keeping the chocolates longer or getting it melted, or storing it in the fridge, you are taking the chance of converting the cocoa butter into a different form which will alter it into a more unappealing flavor.

Resources

1. Owen, Gregory. “How Chocolate Is Made.” www.princeton.edu, 5 Jan. 2013.

2. G Tannenbaum, “Chocolate: A marvelous natural product of chemistry”,.J. Chem. Educ, 2004 – ACS Publications

3. http://www.rsc.org

4. http://www.callebaut.com

5. http://www.pexels.com (photos)