ROME - Researchers have discovered that the oldest wine in the world may have been Italian, after finding traces of 6,000-year-old fermented grapes off the west coast of Sicily.

A team of researchers studied residue in terracotta jars found in a cave on Mount Kronio near Agrigento, Italy. The site was "probably a holy site where offerings were made to the gods", Enrico Greco, a chemist at the University of Catania, said.

"The fact that the jars were found in a cave saved them from being buried and allowed the contents to be preserved, even though it has solidified over the centuries," Greco said.

Several analysis techniques, including nuclear magnetic resonance, revealed the presence of tartaric acid, the primary acid in grapes.

"We ruled out fatty residues from meat or oil, and as there were no traces of grape seeds or skins, we concluded it was from fermented grapes," he said.

The archaeologists then dated the residue by comparing the pottery with other vases from nearby sites.

The finding is significant as it dates the fermented grapes back to the fourth millennium BC, some 3,000 years earlier than the first traces of viticulture previously recorded in Italy.

"When we published our article, we did not imagine it could be the oldest wine ever discovered, but the information has led us to believe this may be the case," Greco said.

He was part of an international group of researchers led by Davide Tanasi, an archaeologist from the University of South Florida who made the discovery, which was published in the Microchemical Journal.

As to whether it is the oldest wine in the world, the scientists remain cautious.

"There have been discoveries from the same period in Armenia, but it seems to have been a drink produced from fermenting pomegranate, not grapes," Greco said, adding: "There are also older signs of rice fermentation in China." — AFP