The Maya are credited with having one of the world’s first written languages, developing a sophisticated calendar system and making advancements in astronomy, mathematics and architecture.

Did you know they also built a better barbecue?

According to archaeologist Stephanie Simms, Ph.D., the indigenous society that inhabited the Yucatan Peninsula in Mexico and parts of Central America from 1800 B.C. to 950 A.D., used dense clay balls to improve heat retention and distribution as they cooked meats and vegetables over an open fire.

Simms, who specializes in the study of ancient Maya foods and cooking practices, discovered hundreds of the balls while digging at the site of a Maya home in Escalera al Cielo in the Puuc Maya region of Yucatan, Mexico. The balls, about one to two inches in diameter and estimated to be more than 1,000 years old, were found among remnants of pots, grinding stones and other artifacts in the home’s kitchen area.

While similar clay balls have been found at other archaeological sites throughout the world, typically they have been dismissed as unimportant and were commonly believed to be ammunition for slingshots (usually by male archaeologists, notes Simms). But Simms’ discovery of the balls in a kitchen setting led her to theorize they were used in cooking or kitchen activities.

She enlisted the help of Francesco Berna, Ph.D., an archaeologist who specializes in ancient pyrotechnology, the study of how early humans first used and managed fire, to analyze her findings. To test the hypothesis, Simms made control balls with soil from the excavation site and exposed some of them to fire in an open firepit.

Berna, an assistant professor at Simon Fraser University in Canada and an adjunct professor at Boston University, used Fourier Transform Infrared Spectroscopy to analyze the mineral content of the balls and establish how they were used. He determined the change in the composition of the clay minerals kaolinite, smectite and mica contained within the balls was consistent with having been burned at 1,300 degrees F. or more, and matched the composition of the balls found at the site.       

Based on the analysis, Simms and Berna concluded with strong probability that the Maya formed the balls from local clay used to make pottery. After the balls were air-dried, the Maya likely used them to line the base of firepit ovens, then built a wood fire over the balls. The fire heated the clay balls, which radiated and distributed heat, boosted cooking temperatures and prolonged the cooking fire.

Because the balls did not disintegrate in the fire, they could be reused again and again. In fact, the location of the ancient balls in a storage area off the kitchen, and not in the hearth itself, further supports the fact that they were being saved to be reused, according to Simms.

Analysis of the exterior of the balls showed they contained residues of maize, squash, beans, arrowroot and other edible plants. Simms also identified residue of maize leaves, which she says were used to wrap ground, mashed or chopped ingredients into tamale-like packets so they could be cooked without direct exposure to the fire – perhaps an early attempt at indirect grilling.

Sampling residues from a grinding stone using a similar method as used to recover food residues from the clay balls.

Simms theorizes that food was also grilled directly over the fire on grids made from sticks, or placed directly on top of the hot clay balls. Lest one believe the Maya hosted only vegetarian barbecues, Simms says there are colonial-period and modern references to the Maya cooking whole turkeys and pigs over an open fire.

“This study proved the balls were culturally significant,” says Simms. “They were important in the Maya’s daily life. They give us insight into what they ate and how they prepared their food. There is evidence that this outdoor cooking practice continues to be used by Maya descendants in the area today.”  

Not to mention barbecuers everywhere. In fact, one could argue these clay cooking balls are the predecessors of modern, stainless-steel, heat-disbursement bars, ceramic briquettes, and glass, ceramic or stainless-steel radiant plates found on today’s gas and infrared grills.

Grill manufacturers’ R&D departments take note and consider: Is there anything that can be learned from this discovery that might have applications today? At the very least, backyard chefs can thank the ancient Maya for building a better barbecue – and the woman who figured it out.