From the jar of dark broth in his hands, Montezuma sipped his 50th hot chocolate of the day as the sun set on his Aztec home. To the south, his Mayan neighbors are credited with the earliest signs of cacao farms and coined the term xocolatl for their chocolate drink, literally translated as “bitter water.” Chocolate has come a long way to become the treat we enjoy as Cadbury eggs and Lindt bunnies. Humans and Oompa Loompas have been under the spell of chocolate for centuries, but what some call magic, others call science.
The ability to have chocolate in beverage form, as bars or an assortment of other treats is thanks to its chemical properties. Not only that but we’ve got different varieties ranging from milk to dark to white, though many argue that this is hardly chocolate.
Cocoa butter gives chocolate the power to melt into decadent goop. Chocolate’s universally acknowledged melting point of 86 degrees Fahrenheit is below that of body temperature so we can enjoy this property with every bite.
Sometimes the opposite is desired: what if you want a crisp chocolate coating, but it keeps melting? The solution is adding coconut oil, a trick Wired magazine recognized Dairy Queen uses for the shell of their chocolate dipped soft serve. The coconut oil has a relatively high solidifying temperature of 76 degrees Fahrenheit, so the chocolate will harden in a matter of seconds as it approaches the temperature of its destination in this case, ice cream.
Easy to consume doesn’t always mean easy to work with as anyone who has tried placing pure cocoa in milk has witnessed. The clumps of powder refuse to dissolve, instead stubbornly sticking together until heated. This is because the starch in the cocoa powder expands on contact with the liquid and forms a capsule around the parts of the powder that haven’t been exposed to it.
Try shaking up a flask of milk and cocoa, and it still won’t mix evenly due to the hydrophobic (dislikes water) cocoa butter. The cocoa is hydrophilic (likes water). Harvard professors Amy Rowat, Kathryn Hollar, Howard Stone and Daniel Rosenberg describe in a lecture plan that by adding a third component that is amphiphilic (liking water and oil), it will act as a glue for the cocoa mass and cocoa butter. This allows for a stable mixture and produces smooth chocolate bars. This mix is called an emulsion, and the amphiphilic component is the emulsifier. In chocolate bars soy lecithin is the most common emulsifier.
Cocoa powder itself is a concentrated version of the cocoa bean. It is a bitter, strong powder in which the majority of the cocoa butter has been removed. This natural powder can result in flavorful chocolates of fruity complexity, but with lesser quality powder this will come off as harsh acidic flavor. A way to combat the cocoa bean’s acidity is to put the powder through the Dutch process. By alkalizing the powder (a chemical process for lowering its acidity), the product achieves a darker hue, more along the lines of Oreo color. The flavor changes a bit, also tasting more like the Oreo cookies.
So not only can it be a creative medium, but a chocolate a day can potentially keep the doctor away. After time spent working for Nestle Stephen T. Beckett wrote in his textbook “The Science of Chocolate” that it is riddled with antioxidants from the flavonoid category, one of which is called catechin. It is one of the most powerful antioxidants, of which dark chocolate possesses 100 grams — about four times that of tea. If eaten in reasonable quantities, issues such as obesity and tooth decay should not arise from chocolate consumption. Rather, heart disease risk may be lowered as things such as healthy cholesterol could be promoted. This is because the flavonoids have anti-blood clotting and anti-inflammatory effects.
People who eat chocolate may experience happiness due to feel-good endorphins released in the brain. It also contains compounds that could trigger cravings later on, but it is generally agreed upon that addiction to chocolate from a chemical standpoint is unlikely. At the end of the day, Montezuma would probably say he just really likes it.