A new class taught by chemistry professor Pedro Bernal uses a tasty treat to explore issues of scientific and cultural importance.
Pedro Bernal (Photo by Scott Cook)
It’s 3 p.m. on a gorgeous spring Friday when chemistry professor Pedro Bernal hears a knock on his half-open office door.
A student peeks inside, eyes fixed on a small, white bowl. No need for her to explain what she’s after, but it’s a good time to share how midterms are making life a little stressful. A chocolaty pick-me-up sure would be nice.
“Here you go,” Bernal says, scooping out a few peanut butter cups while offering words of encouragement. “Always here if you need me.”
For the Willy Wonka of the Bush Science Center, it’s a scene that plays out multiple times on any given day. Rollins students know they have a generous friend in Room 367, a professor whose love of chocolate serves as a vehicle for building personal connections and communicating global knowledge.
Last fall, Bernal taught a class to first-year students called The Science and Culture of Chocolate. Part of the Rollins College Conference (RCC) program—an interactive seminar based on a broad range of topics— the course explores how chocolate provides insights into issues of historical, scientific, and economic significance. This fall, the course will be offered in the ICE Neighborhood, part of a curriculum group that aims to innovate, create, and elevate.
“Studying chocolate allows you to touch on just about anything—from the anthropological and cultural impacts in the early days to today’s business of free trade,” says Bernal, who is in his 30th year of teaching at Rollins. “We also concentrate on the physical properties of chocolate as a substance that needs to undergo some kind of fermentation. The science is fascinating, but there’s a lot more to the course.”
Eureka in Hispaniola
The idea for a chocolate class goes back to 2000, when Bernal visited his native Dominican Republic on a yearlong sabbatical. Over dinner one night, some friends told him about plans to expand their family’s century-old cacao business. But first, a lesson in etymology.
Cacao (pronounced “kuh-kow”) is chocolate in its purest form, the beans inside giant pods produced by cacao trees that grow in tropical climates near the equator. When roasted at high temperatures, raw cacao becomes cocoa powder. Over time, the words cacao and cocoa have become mostly interchangeable in the English dialect—even if, technically, they refer to separate things.
“To be clear,” Bernal says, “this is not a class on Hershey’s. We talk about those kinds of companies to make the contrast, but the harvesting of cacao beans is a very different business.”
Now, back to dinner. The Dominican company, Rizek Cacao, was looking to scale its operations and grow into bigger markets. A key part of the equation involved creating a scientific infrastructure to master the fermentation process in order to potentially create distinctive flavors and to pass organic certification from worldwide organizations such as Rainforest Alliance, USDA Organic, and Bio Suisse.
Naturally, the chemist in Bernal found the subject intriguing. And at a time when more and more Americans were paying $5 or $6 for artisanal cacao bars, he also recognized the newfound economic opportunities that foreign companies like Rizek Cacao wanted to pursue in processing and exporting.
Bernal has never had an official role in the company, yet he has keenly followed its progress from Winter Park. Through the years, he stayed in contact with the Italian scientist whose work has helped Rizek Cacao diversify into numerous areas of business and become a leading producer of organic chocolate products.
In 2014, when Rollins approached Bernal about developing a new class that blended various disciplines of the liberal arts, chocolate immediately came to mind. That fall, Bernal taught the course for the first time alongside Associate Professor of Anthropology Gay Biery-Hamilton as part of the honors program. The next year, the course transitioned to the RCC.
Pedro Bernal (Photo by Scott Cook)
History and Culture
The story of chocolate begins 5,500 years ago, when the Mayo Chinchipe culture began harvesting cacao beans in an area that straddles the border of Peru and Ecuador. Eventually, this “food of the gods” became integral to the Maya and Aztec cultures, who used it for such things as currency, medicinal drink, religious customs, and burial purposes. Glyphs representing cacao appear frequently alongside warriors, nobility, and priests in ancient ceramics and carvings.
According to Beth Kimmerle’s Chocolate: The Sweet History, the Maya began cultivating the cacao tree on the Yucatan Peninsula between 250 and 900 A.D., effectively creating the first
cacao farms. Roasting the tree’s beans and grinding them into a paste produced a drink they called “xocoatl”—literally “foam water.”
When conquistadors arrived in the early 1500s, they quickly realized cacao’s value— not only to Montezuma’s vast Aztec empire but also as a promising delicacy in Spain.
A century later, Italy, France, and England were drinking a new beverage, enriched with sweetener and milder European flavors than the bitter and spicy Central American variety.
“By the mid-18th century,” Kimmerle writes, “chocolate secured a place on the list of items that became fully integrated into European and colonial life. ... In 1773, when furious American colonists were fed up with taxation on tea, their hot beverage of choice, they dumped incoming cargo into Boston’s Charles River. They began to import cacao from nearby producing colonies in the Caribbean Islands, thereby circumventing England’s taxes.”
Soon, technology advanced to the point where cocoa butter could be separated from the dried beans—a game-changing dynamic, as it led to the manufacture of solid chocolate.
Today, of course, most people can scarcely imagine life without chocolate. From Easter eggs to avant-garde fashion shows in which models wear only—you guessed it—this ubiquitous confection has morphed into an integral part of the human experience.
But what makes chocolate, specifically the cacao bean, such a popular commodity for mass consumption and production? That’s where Bernal drives home the science behind the world’s favorite guilty pleasure.
Students start by learning about cacao’s molecular structure and physical properties. From there, they explore the production process, which includes fermentation (how cacao reacts with yeast and bacteria), roasting (essential for flavor and aroma development in addition to fermentation), winnowing (removing the shell), conching (essential to getting the right texture) and using pressure to extract the beans’ cocoa butter.
According to Ginger Tannenbaum, author of Chocolate: A Marvelous Natural Product of Chemistry, the resulting “chocolate liquor”—no alcohol present— is composed of about 55 percent fat, 17 percent carbohydrate, and 11 percent protein, with the remainder mostly tannins and ash. Depending on its source, this liquid may also contain theobromine (a smooth muscle stimulant) and caffeine (a central nervous stimulant).
“Basically,” Tannenbaum writes, “all manufactured chocolate confectioneries are chocolate liquor with optional additions of sugar, cocoa butter, cocoa solids, and condensed or dried milk. Products differ by the quantity of the various ingredients present.”
Regardless of their final composition, all chocolate bars are unique—from a molecular standpoint, at least—in that they are crystalline solids. Other things we eat that fall into this category include ice, sugar, salt, and butter. Six kinds of crystals are present in chocolate, but only one is needed. To produce the perfect bar, manufacturers must heat liquid chocolate to the right temperature to dissolve the unwanted forms of crystals—a process known as tempering.
“There are very few commodities you could study that blend so many elements of the liberal arts,” Bernal says. “You could do something similar with coffee or tea, without question, because of its political and cultural significance. But coffee and tea do not ferment, so you lose out on a big part of the scientific element. With chocolate, the bean is just the start of a really interesting and complicated process.”
As an example, Bernal points to how chocolate’s perceived health benefits—from the physical (enhanced cardiovascular functions) to psychological (feelings of euphoria)—have grown into the stuff of legend. His students delve into these topics as well, looking into the myths and realities of how chocolate’s biologically and pharmacologically active compounds interact with the human body.
While scientific opinions vary, one rule of thumb is that chocolate bars with greater percentages of cacao—such as the high-dollar artisanal varieties—are better for you because they contain more of a naturally occurring antioxidant called flavanol.
“The positive effects seem to be limited to dark chocolate, the milk in milk chocolate apparently interfering with flavanol absorption in the gut,” according to the Karger Gazette, a biomedical research journal used in Bernal’s curriculum. “The flavanol content of different products can also vary greatly depending on how the chocolate is processed: roasting and other manufacturing procedures can reduce the flavanoid content by as much as 90 percent. Some manufacturers are now probing their production lines to see if and where the flavanols are being destroyed and taking steps to stop this. If the evidence from new studies continues to indicate the beneficial properties, we may well start to see flavanoid contents printed on the wrappers of chocolate bars.”
Pedro Bernal (Photo by Scott Cook)
Growing, Processing, and Marketing
In the United States alone, chocolate is a $17-billion industry. Globally, that number is closer to $140 billion.
For a country like the Ivory Coast—the world’s biggest producer of cacao—this can be a blessing and a curse. On one hand, harvesting chocolate’s main ingredient provides jobs for about 25 percent of the population. On the other, it has contributed to widespread government corruption, inhumane working conditions, armed conflict, child labor, and even child slavery.
Dealing with the dark side of chocolate— and trying to ensure ethical practices by its suppliers—is a constant headache for every industry giant. In the early 2000s, for instance, Nestlé promised to end the use of child labor in its supply chain. In 2013, however, the Fair Labor Association found child workers at 7 percent of the Nestle farms it visited in the Ivory Coast.
Across the Atlantic Ocean, the Dominican Republic produces a mere 4.7 percent of the Ivory Coast’s annual cacao output. Yet this small island nation is becoming an increasingly important global player in two key areas: ethics and quality.
The country is a leader in Fair Trade- certified cacao, meaning that global trade organizations ensure its farmers receive adequate compensation for their crops. And considerable changes over the past 20 years have elevated the Dominican Republic’s reputation for quality organic exports, as post-harvest handling techniques have improved the drying and fermentation processes.
According to a 2013 report commissioned by British chocolate company Green & Black’s, this approach has paid dividends.
“In the U.K. and other countries,” the report found, “an increasing number of chocolate bars are explicitly marketed as using beans sourced from the D.R. As such, the D.R. would seem ideally placed to further consolidate its standing in the global chocolate market, which is seeing an increased demand for ethically produced, high-quality cocoa.”
Students analyze these issues as part of their semester-long case study, “Growing, Processing, and Marketing Chocolate in the Dominican Republic.” Eventually, Bernal would like to incorporate an international study component aswell, taking future classes on a trip totour the country’s cacao plantations and businesses. He has been taking students to the Dominican Republic for 20 years to work on water projects, and in recent years, students have visited plantations and Rivek’s chocolate factory. For now,just being able to take abstract concepts and make them engaging is reward enough.
“When the entire class is built around a fun, singular theme,” Bernal says, “I’ve noticed that students can more easily comprehend a wide range of challenging material.”
Biology major Shaina Cordas ’19 agrees. “Learning about chocolate gave me a better understanding of the liberal arts because I now know where it comes from and how it is manufactured,” says Cordas, who makes it a point to buy only Fair Trade-certified bars. “One of my favorite parts of this course was when we made different recipes and shared them with the class. It was a fun way to try new things.”
To Bernal, that’s what it’s all about
Pedro Bernal isn’t the only Rollins educator who uses chocolate to teach.
Historical Importance In Pre-Columbian Mesoamerican societies, servants to the elite would pour liquid chocolate into special vessels to make it frothy. This chocolate drink—often mixed with tropical spices—was considered to be an aphrodisiac that also carried other health benefits. For nutritional value, soldiers created a more rudimentary concoction by adding water to the dried and compressed cacao pellets they carried while on the march. Cacao beans were also used as currency, and vast trade networks developed from Central America and probably up through the North American Southwest. Cacao was so important that wars were fought to gain control over areas where it was produced. — Gay Biery-Hamilton, professor of anthropology
Cultural Legacy Today, contemporary indigenous peoples in Mesoamerica continue to regard cacao (spelled “kakaw” in Maya) as sacred, preparing it by grinding the bean by hand and mixing it with toasted spices like cinnamon and cloves to make a paste. They then dissolve this paste in a hot water and sugar solution and serve the drink to guests out of small red- and yellow-painted gourds during celebrations, ceremonies, and other ritual events. The glyph for cacao is prominent in Maya hieroglyphic writing, and students at Rollins learn how to decipher its meaning as part of my The Maya class. — Ashley Kistler, chair of the Department of Anthropology
Cacao Trees at Rollins About 15 to 20 years ago, I got to work one day and there was a 3-gallon cacao tree sitting by the front door of the greenhouse. Bill Grey, an adjunct professor at the time, had planted and grown the tree at home, but it was getting too big for him to take care of. Today, in addition to that tree, Rollins has four smaller ones, plus a few seedlings—all grown from the original tree’s seeds. Our cacao trees are usually used on scavenger hunts when professors want students to familiarize themselves with the greenhouse and its collection of plants. — Alan Chryst, Rollins greenhouse manager
Science and Health Bitter, acidic, astringent, sweet: chocolate has one of the most complex flavors of any food. Chemists have identified more than 600 unique volatile molecules in chocolate that, together, comprise its richness. Unfortunately, the ancient reputation of cocoa-based elixirs as medicines or aphrodisiacs is not backed by modern science. However, pure theobromine, one of the chemical components of cacao, effectively inhibits coughing in guinea pigs. Like any food, chocolate may have positive health benefits when eaten in moderation as part of a balanced diet. Plus, it’s almost guaranteed to make you happy! — Kasandra Riley, assistant professor of chemistry