Mexican researchers uncover 1,000-year-old earthen pits used to process corn

Circular earthen pits built into the ground at an ancient ceremonial complex in central Mexico were likely used to process corn a thousand years ago, Puebla News daily reported Wednesday.

Four small thousand-year-old pits uncovered at the Old Tehuacan ceremonial complex in Puebla state "could be evidence of pre-Hispanic nixtamalization work," the daily said, citing researchers at the National Institute of Anthropology and History.

Nixtamalizing corn requires soaking the kernels in an alkaline solution, usually made with lime water, before hulling and grinding them for cooking.

The pits date back to 1000-1350 A.D. and were discovered in different parts of the 126-hectare complex, said Noemi Castillo Tejero, an archaeologist who has been researching Tehuacan for two decades.

The pits were reportedly located near kitchen areas, where comals (flat griddles used to heat food) were found nearby. Each pit, with a diameter of 60 centimeters, was made from a mixture of clay and lime, and could hold up to five liters of water.

These discoveries may prove that "tortillas were produced in this area where priests and authorities of the Popoloca (Indian tribes) lived," said Tejero.

Researchers ruled out the possibility that the pits could have been used to collect and distribute water, since they were separated from the site's complex rainwater gathering system.

In that system, rainwater was stored in giant cisterns capable of holding up to 20,000 liters of water and channeled throughout the site via a network of canals that ran along the main plazas.

Archaeologists plan to place the pits under the microscope to detect whether remnants of corn will confirm their theory, said Tejero. Endi