Residue scraped from pottery vessels dating from 1400 B.C. to 1100 B.C. indicate Ulua Valley residents fermented the chocolate plant's sweet pulp to make an alcoholic drink before they began grinding the bitter seeds, mixing them with honey and chiles to produce the equivalent of modern cocoa, the Los Angeles Times reported Monday.

The consumption of fermented cacao plants is much more recent than the production of wine and beer, which date back to about 5400 B.C. in Iran and around 7000 B.C. in China.

The chocolate drink, which had an alcoholic content of about 5 percent, had a role in feasting, entertaining and binding groups together, said archaeologist John Henderson of Cornell University in Ithaca, N.Y., who led the team reporting its findings in the Proceedings of the National Academy of Sciences.

For more than 10 years, Henderson and archaeologist Rosemary A. Joyce of University of California-Berkeley have been excavating the Ulua River site, called the "Cradle of Chocolate" because of its fertile soil and conditions for growing cacao beans.