The human love affair with chocolate is at least 3,000 years old -- and it began at least 500 years earlier than previously thought, according to new analyses of pottery shards from the Ulúa Valley region of northern Honduras.

But the first people to appreciate the cacao tree were probably after a buzz of another kind -- a fermented, winelike drink, research shows -- and only later discovered the chocolaty taste we love today.

In research published in the Nov. 27 issue of the Proceedings of the National Academy of Sciences, Cornell professor of anthropology John Henderson and colleagues found traces of caffeine and theobromine, an alkaloid similar to caffeine but specific to cacao, in 11 shards dated to 1100 B.C. The samples came from excavations directed by Henderson and University of California-Berkeley anthropology professor Rosemary Joyce at a site known as Puerto Escondido.

The findings offer chemical evidence for the earliest cacao consumption anywhere in the world.

In the past, the only chemical detection of cacao in ancient pottery required an intact vessel and a substantial amount of residue, Henderson said. To detect much smaller chemical traces in broken shards, co-authors Patrick E. McGovern and Gretchen Hall at the University of Pennsylvania Museum and W. Jeffrey Hurst at Hershey Foods used new extraction techniques along with liquid chromatography, gas chromatography and mass spectrometry -- techniques that could be used for sensitive chemical testing on many more remnants in the future.

"It's not very often that you find a whole vessel," said Henderson. "Now that you can process things from people's trash piles, you can see in much better context how these things were being used."

But while cacao beans (seeds) and the spicy, frothy chocolaty drink they produced were the stuff of royal ceremonies and elite gatherings in later millennia, Henderson said, it's likely that the earliest cacao drinkers made a simpler drink by fermenting the pulp around the seeds. The result (which at least one brewing company, in collaboration with McGovern, is working to reproduce) was a brew that tasted nothing like chocolate.

Since both beverages contain theobromine and caffeine, chemistry doesn't reveal whether a vessel held a winelike quaff made from pulp or the celebrated chocolate concoction made from seeds. But while the jugs of later, chocolate-drinking periods were short and wide, with broad openings to allow for pouring back and forth to create froth, the earlier bottles had long, skinny spouts that would frustrate the most diligent Starbucks froth specialist.

Over the ensuing centuries, Henderson said, the drink was traded, shared and used in ceremonies, creating social networks across the region and beyond.

"The upwardly mobile families were using cacao, serving it as part of a strategy for distinguishing themselves," he said. "It was a way of creating social obligation and political power locally and with people in distant villages. It's that context that gives us a way of understanding how it is that potters in villages hundreds of miles apart have the same understanding of what vessels should look like."

And over time, people likely discovered that the fermented seeds, not the pulp, were the real discovery.

"If we're right about the shift from wine made from pulp to chocolate made from seeds," said Henderson, then all the pomp and luxury that surrounded chocolate in later years -- "the control of cacao plantations by kings and chiefs, all the fancy serving of chocolate in the Aztec courts that so impressed the Spaniards, and the modern chocolate industry that developed from that -- all that was an unintended consequence of some early brewing."