The Science of Chocolate

Molecular structure model of theobromine molecule with chocolate cubes on bright background. Structural chemical formula of theobromine is written on the notebook. Black=C, red=O, blue=N, white=H.


When people think of chocolate, they usually think of the sweet, high calorie treat that can be purchased in grocery stores or candy shops. What many people don’t know about chocolate is that it starts out as an almost inedible bitter bean.

So what is the science of chocolate that takes it from bitter bean to sweet indulgence? The key to good chocolate is found in its chemical composition. It’s what creates chocolate’s allure as well as its many health benefits. The science of chocolate is what keeps us coming back for more.


What Is the Science Behind Chocolate?

To discover chocolate science, let’s go back to the beginning. Chocolate has a long, rich history that dates back thousands of years to ancient civilizations.

Where was chocolate discovered? Chocolate’s origins can be traced back to Mesoamerica (current day Central and South America). It comes from the cacao bean, which grows on the Theobroma cacao tree in tropical climates in Central and South America, Asia, and Africa. Cacao beans grow on these trees in pods and go through many steps, such as harvesting, fermenting, and roasting, and travel many miles to become the chocolate we buy from craft makers or grocery stores.

The Theobroma tree grows only in tropical areas within 20 degrees of the equator. Any farther away, and the air is too cold for the trees to grow. Midges, which are small flies no bigger than the tip of a pencil, pollinate the small, white flowers of mature Theobroma trees. The pollinated flowers produce football-shaped pods in which the cacao beans develop. The leathery skin on the cacao pod turns from green to yellow as it ripens. Each pod is filled with a mucus-like white pulp that surrounds and protects an average of thirty cacao beans. When ripe, the pods are harvested by hand with a machete.

After harvesting, the next step is fermentation. The combination of pulp, cacao beans, hot temperatures and high humidity encourages microorganisms to grow, and these microorganisms digest the pulp that surrounds the cacao beans. This helps convert the sugars in cacao beans into acids, which decrease the overall bitterness of the beans. The bacteria and yeast produced by the fermentation process create the compounds necessary to give chocolate a floral aroma and effect the flavor. The composition of chocolate is quite complex and contains over 200 different flavor compounds.

Once fermentation is complete, cacao farmers separate the beans from the pulp and spread the cacao beans in the sun to dry. It is during this process that water is removed from the cacao beans, meaning mold, bacteria and yeast can no longer live. Once dry, the cacao beans are roasted to remove even more of the acidity.

When the roasted shells of the cacao beans are removed, cacao nibs are left behind. Some chocolate makers treat cacao nibs with an alkaline solution to further reduce the acidity.

The next step in chocolate making is conching, which is a two-part process that turns the gritty cacao nibs into a paste through grinding and heating. Many of the flavor compounds formed during the fermentation and roasting stages that give cacao its acidity are removed during conching.

To complete the process from harvesting to finished product, cocoa butter is added after conching. Cocoa butter decreases the viscosity (or thickness) of the chocolate and makes the mixture easier to work with.


What Is the Scientific Name for Chocolate?

The scientific name for the cacao tree—Theobroma—is derived from Latin and means “food of the gods.”

We know chocolate was discovered in Central and South America, but who discovered chocolate? Archaeologists have found cacao residue in pottery used by the ancient Mayo-Chinchipe culture over 5,300 years ago. They lived in what is now the southeastern region of Ecuador. The ancient Olmecs of southern Mexico are one of the earliest civilizations known to have partaken of chocolate—there’s evidence the Olmecs cultivated chocolate as early as 1750 BC.

The Olmecs most likely passed on their knowledge about cacao to the Mayans. In the Mayan culture, chocolate was enjoyed by everyone, regardless of class or status. The Mayans also used cacao beans as currency and in ritual ceremonies.

The Aztecs were the first to create a cold, bitter chocolate drink called xocoatl, while the Mayans preferred warm chocolate. Both cultures drank their chocolate instead of eating it, and they added chili pepper, allspice, vanilla and honey to both hot and cold chocolate drinks.

The Aztecs took reverence for the cacao bean to another level. They considered cacao beans to be more valuable than gold. Their chocolate drink was an indulgence enjoyed by the rich, although the lower classes could occasionally enjoy it at weddings or other celebrations.

According to legend, Montezuma II drank several gallons of chocolate each day for energy and as an aphrodisiac. The Aztecs believed that chocolate invigorated men and released women’s inhibitions. This ancient culture also used chocolate for medicinal purposes. High-ranking Aztec and Incan officials used chocolate to help relieve stress.


Chemical Properties of Chocolate

What is the chemistry behind chocolate? Chocolate contains between 300 and 500 different known chemicals, some of which interact with brain chemistry and can alter mood and give chocolate its addictive, euphoria-inducing qualities. Some of the most prevalent chemicals in chocolate include the following:
  • N-oleoylethanolamine and N-linoleoylethanolamine. These inhibit the breakdown of anandamide, which occurs naturally in chocolate and plays a role in pain, appetite, memory, depression and fertility. These chemical properties also increase sensory properties of chocolate like smell and texture to induce cravings.
  • Phenylethylamine. This chemical promotes a feeling of pleasure or excitement as well as apprehension.
  • Serotonin. This acts as a mood stabilizer. It helps regulate sleep and improves mood. It also helps improve learning and memory functions.
  • Theobromine. This is a weak stimulant that can be used to treat high blood pressure and the accumulation of bodily fluids. However, in large doses, it can be toxic, and it is especially harmful for dogs (and the reason our furry friends can’t eat chocolate). The higher the percentage of cacao in a chocolate bar, the higher the amount of theobromine.
  • Tryptophan. This chemical inspires a feeling of happiness.

Additional chemical properties of chocolate include compounds like tetrahydro-beta-carbolines, epicatechin and procyanidins.

When cacao beans are roasted, a cascade of chemical reactions occurs between the amino acids that form during fermentation and the sugars in the grain. These reactions lead to the compounds responsible for the flavor and taste of chocolate and also form the compounds that give chocolate its dark brown color.


Is Chocolate Good or Bad for You and What Does the Science Say?

Dark chocolate, especially, is known for a variety of health benefits—from protecting heart health to improving memory to boosting energy. It’s packed with antioxidants and flavanols and all the good things those provide. Ancient cultures like the Aztecs and Mayans enjoyed the benefits of cacao beans many centuries before scientists began to study those benefits. Some of the health benefits scientists have uncovered include the following:

  • Improves cognitive performance
  • Protects heart health
  • Contains an abundance of minerals
  • Reduces chances of stroke
  • Reduces memory decline
  • Reduces stress
  • Reduces level of LDL “bad” cholesterol
  • Creates healthy skin
  • Reduces inflammation

Several studies in recent years have focused on the power of dark chocolate to help with cognitive functions and improved mood.

Researchers from University College London studied almost 14,000 people and found that those who ate dark chocolate within two 24-hour periods were 70 percent less likely to have symptoms of depression than those who didn’t eat chocolate at all.

Italian researchers studied the effect of chocolate on cognitive abilities. They looked at 10 studies involving a total of 467 subjects, and in nine of those 10 studies, participants who ate cocoa or chocolate (and thus, of flavanols), had at least some increased proficiency on cognitive tests. The flavanols in chocolate helped reduce cognitive decline after a night of sleep deprivation, and consuming chocolate each day had a long-term positive impact on older adults who were starting to suffer memory declines.

Research from two studies presented at the Experimental Biology 2018 annual meeting in San Diego showed that consuming dark chocolate with at least 70 percent cacao has positive effects on stress levels, inflammation, mood, memory and immunity.

In the Cococlectic chocolate shop, we sell only dark chocolate bars. We feature a different American small-batch bean-to-bar chocolate maker each month. These chocolate makers are passionate about their craft and produce chocolate from scratch using only three main ingredients: cacao beans, sugar and cocoa butter.

The chocolates at Cococlectic are vegan, non-GMO, fair-trade and ethically sourced. They do not contain any soy, gluten, dairy or nut, but they may be produced in a facility that handles these ingredients.

We offer one-time gift boxes with dark chocolate bars only or mixed bars with nuts or fruit. We also have corporate gift boxes that are available with the purchase of the Office Box. Each chocolate box comes with 4 full-size dark chocolate bars that are made in the US.


Sign up for our chocolate-of-the-month subscription club and join us for a free virtual chocolate tasting with our featured chocolate maker of the month.