Sweet science

Patrick McGovern and Gretchen HallPhoto credit: Candace diCarlo

Chocolate can come from as far away as Belgium or as nearby as Hershey. It can be white or dark. It can be whipped into a mousse, melted into a hot topping or broken off from a candy bar.

But years and years ago, it had a much different purpose: It was consumed as an alcoholic beverage.

Analyses of pottery excavated from a site in Honduras has led Patrick McGovern, senior research scientist at the Penn Museum’s Applied Science Center for Archaeology, to conclude that ancient people were drinking fermented beverages made from the sweet pulp of the cacao fruit—the source of modern-day chocolate—somewhere between 1400 and 11 B.C.E.

This is the earliest known use of cacao, dating to long before a drink made from the beans was served at special ceremonies and feasts of Mayan and Aztec kings.

And McGovern, who has spent much of his career studying ancient food and drink, says this is an important finding. “My research suggests that these kinds of fermented beverage cultures were really right at the core of the development of human civilization.”

McGovern’s background is as unique as his field of choice. He was a chemistry major who also studied brain research. He received a Ph.D. in Near Eastern Languages and Literature from Penn, and also got a fellowship in Penn’s radio-carbon lab. Studying ancient food and beverages, McGovern says, allows him to enjoy both the sciences and humanities.

“I always had kind of a split mind about whether to go into the sciences or humanities,” he says. “As I was finishing work on my dissertation, I was also getting exposed to all these science-in-archaeology approaches. It has evolved into a highly interdisciplinary approach.”

Q. What were you looking for in the vessels uncovered in Honduras?
A.
What we’re specifically interested in these very early vessels is to see whether they held a cacao beverage and is so, were there any additional additives to the drink. The hypothesis was that the impetus for eventual cultivation and domestication of the cacao tree was, at first, people were attracted to the very sweet fruit or pulp that surrounds the bean, which is about 10 percent sugar. You can make a fermented beverage from this, and they still do in parts of Latin America today. It comes out to be about 5 percent alcohol.
In the earliest stages, they wouldn’t have started adding all of these exotic ingredients that they do later on when they’re working with the bean. In order to offset the bitterness of the bean, they would use things like honey and spike it up a little bit using chili, and add different kinds of aromas and flavors by putting actual flowers into the bean beverage. Our analyses showed that there weren’t any additives, which fit with our hypothesis that [the beverage] would be made from the fruit in these earlier vessels.

Q. How exactly do you do your analysis?
A.
What we are trying to do is tease out the ancient organic molecules from ancient pottery samples. How Gretchen Hall [pictured above] and I do that is we have to get the organics out of the pores of the pottery. They’re held in place pretty well because of the ionic structure of the ancient pottery. We have to get out these ancient organics by solvents like methanol or chloroform, even water, which is very good for getting out the compound that we’re interested in, which is called theobromine. That’s actually the name of the tree—theobroma, which means ‘food of the gods.’ Theo, ‘god,’ broma, ‘food.’ Theobromine is only found in the cacao plant in Central America. So if you can identify theobromine in the ancient extract, then you have some kind of cacao product. The shapes of the ancient vessels tell us it was a liquid.
The gas chromatograph is able to separate out the various compounds and then pass it into a mass spectrometer, where you can get an exact mass for different fragments. There’s a very large database that we [use to] compare the various fragments, to identify the original compound.

Q. What’s the significance of these findings?
A.
It’s a very interesting and important finding for the New World. We’ve established that grape wine was being developed and produced in the Near East around 6,000 B.C., and then recently, we’ve shown that the Chinese had developed a fermented beverage around 7,000 B.C., that included hawthorn fruit, grapes, rice and honey. Humans have always been attracted to fermented beverages, it seems, and it enters into our cultures in really significant ways--socially, religiously and econmically--in not just the earliest Neolithic cultures, but in California, Washington and Oregon, where back in the 1960’s a few enterprising souls after prohibition started to plant grapes out in Napa Valley.

Q. And chocolate?
A.
For the Americas, chocolate plays an extremely important role with the Mayans and the Aztecs. It was the prerogative of the king to have lots of chocolate beverages. A cacao bean served as the currency. When Cortez came to the capital of Montezuma, he found out the storerooms were piled high with something like a billion cacao beans. This was the standard of currency.

Q. Any idea how this tasted? You mentioned it is still consumed today. Have you tried it?
A.
I’d like to go down to areas that still produce the beverage made from the bean, with the additives like honey and chilies and so forth in Mexico, and taste it. We often try to recreate the beverage to find out more about how it was made and to find out if the ingredients really work as a beverage. You want to also try to make something that’s drinkable, too.
We did an analysis of a tomb in central Turkey that is possibly the tomb of King Midas and then had a competition of microbreweries to try to replicate this beverage. The brewery that turned out best in my estimation was a place down in Delaware—Dogfish Head.
[With Dogfish Head] we decided to do a version of the chocolate bean drink—the later drink, the drink of the Aztecs. What we did in this first trial run is to take some very fine dark chocolate from an area close to Honduras in southern Mexico and then mix it with some corn or maize, honey, and chili—a rather mild chili—and then an herb called achiote, which gives a very intense reddish color to the beverage. The Aztecs actually equated the chocolate drink with blood. Right now, that’s fermenting, so we haven’t had a taste of it yet. But it’ll be the first time that this kind of beverage has been prepared in the United States.

Q. These beverages led to the domestication of these plants—and eventually to chocolate. How did that happen?
A.
Some people argue that the original domestication could have occurred in northern South America. Other people argue for Central America—especially the area where the site is located in Honduras. What does seem to be clear is that the Central American people really focused in on the beverage, especially when they started making it from the bean. ...The ancient Aztecs and Mayans didn’t just drink it, but they had special tools to foam it, or they would pour it from one vessel to another and create a head and foam on top of the beverage.
If the Central American people are very interested in these beverages, and they seem so, more than South Americans, the argument would be, they’re the ones that had the most to gain from domesticating.

Q. How do you think your study of ancient beverages can illuminate the lives and practices of past cultures?
A.
It shows us that humans are very attracted to high-sugar foods to begin with, but in addition, they are attuned to what’s happening in their brains, to mind-altering substances that might open up a better understanding of what’s going on in the visible and the invisible world beyond. They’re living in environments that are pretty challenging. The average age of death might be only 30 or 35. You’re going to look very carefully in your environment for anything that’s likely to help you to be more healthy, to cure disease, but also to perhaps gain an understanding of how this world is operating. People who were drinking fermented beverages tended to live longer and reproduce more because alcohol kills the microbes that cause many diseases.
In addition, the fermentation process itself seems otherworldly, because you see the bubbling of the carbon dioxide as the yeasts are working. When you drink the beverage you get some mind-altering effects. Ancient peoples around the world have interpreted this as a means to contact the gods who are basically controlling our destiny.
We’ve started to see how a lot of these herbs and spices that we detect in these ancient beverages also played a very important role in the primitive medical practice. Even if you look at Greek and Roman medicine—Hippocrates and so forth—they mainly talk about the advantages of wine for treating different illnesses. That got us thinking that we should explore that avenue more. We recently started this project with the Abramson Cancer Center to test some ancient compounds for anticancer drugs.

Q. What compounds are you testing?
A.
We’re very interested in a plant that we identified in our ancient Chinese beverage [Chateau Jiahu] that goes back to 7,000 B.C. Wormwood species … are some of the most bitter compounds known. We found out that people have already detected some anti-cancer effects and also it’s a very good anti-malarial. ...There’s a set of compounds called terpenoids which we’re going to explore. There’s quite a number of other types of plants that we could look at.

Originally published Dec. 6, 2007.

Originally published on December 6, 2007