Cacao Scientific Investigation: Using Modern Technology to Solve the Ancient History of Cacao

In 1984, archaeologists discovered a Classic Mayan tomb containing a cache of 14 pottery vessels in Rio Azul, in the Petén region of Guatemala. The tomb was the burial site of a latter half of the 5th century AD ruler.  Some of the 14 vessels were shaped in what archaeologists knew were cacao beverage containers. One pot was unique, a stirrup-handled pot with a screw on lid, covered in stucco and painted with 6 hieroglyphs.  This pot, and some of the others had a dark ring on the inside, residue of the liquid that filled the pots when the ruler was laid to rest. Anthropologists and epigraphers believed one of them was the glyph for kakaw (cacao). How could they find out if what they thought was correct? Who could they talk to about an ancient chocolate mystery? They called the 800 number of America’s main chocolate producer of course. They called Hershey’s customer service line.

Four years after the tomb’s discovery, anthropologists from the University of Texas San Antonio contacted the Hershey Company’s customer service line. They had some pottery vessels they said, and they wanted to know if the vessels had been used to hold cacao. The anthropologists wanted to arrange tests, and asked the company for advice. Hershey’s passed their call on to W. Jeffrey Hurst, one of their analytical chemists, and with the company’s blessing he tried to figure out how and what to test for when looking for cacao.

W Jeffrey Hurst

Hurst, pictured above with the stirrup-handled pot, examined the over 500 compounds that cacao contains, and picked a combination of two that 1. do not occur together in any other plants in Mesoamerica and 2. are stable enough to have lasted through the intervening centuries.  These compounds, theobromine and caffeine, have become the benchmark compounds for cacao. Using the modern investigative tools of “high performance liquid chromatography coupled to atmospheric-pressure chemical ionization mass spectrometry,” amongst others, Hurst was able to test the vessels for the compounds, confirming that some of the vessels from had contained cacao and that the stirrup-handled pot was one of them. His findings helped epigraphic scholars confirm the Mayan glyph for kakaw, or cacao, helping epigraphers firmly break the code for Mayan writing.

Although the ancient history of cacao and chocolate is not his day to day job, in his 25+ years of ‘side work’ Hurst has become the resident expert in analyzing cacao residue. In 2006, he announced that he could now test scrapings from archaeological ceramics of all kinds, including plates, bowls and other serving dishes. The improved testing method has proven that cacao was not just consumed as a beverage; it was an ingredient used in cooking sauces for protein based dishes. This last discovery, using pottery from Honduras dating back to AD 450, has broadened the anthropological study of the ancient cultures that valued cacao so highly. Hurst’s work, started from a simple inquiry to a customer service line, has vastly increased the world’s anthropological and archaeobotanical knowledge of cacao.

Who are you going to call?  Hershey’s.

Works Cited

Coe, Sophie D. and Michael D. Coe. The True History of Chocolate. London: Thames & Hudson Ltd., 2013. London.

Keiger, Dale. “Sweet Science: Unearthing chocolate’s ancient history.” <>

Tried, Bijal P. “Ancient Chocolate Found in Maya “Teapot”.” <>

Nieburg, Oliver. “Interactive Map: Top 20 chocolate consuming nations of 2012.” <>

Presilla, Maricel E. The New Taste of Chocolate Revised. New York: Ten Speed Press, 2009. Print.


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