However, solid evidence had been lacking until a Chinese-American team studied potsherds - radiocarbon-dated at 7000 BC to 6600 BC - from the oldest portion of Jiahu, a village from the Neolithic period in Henan province. This cultural period is characterised by primitive crop growing and the use of flint tools and weapons.

The team compared residues extracted from the potsherds with liquids remaining in tightly sealed vessels dated to the Shang dynasty. Their analysis of the Jiahu residues revealed traces of compounds found in rice, as well as the ancient Shang dynasty wines.

They found that 13 of the 16 potsherds tested had contained the same material. It was "a consistently processed beverage made from rice, honey and a fruit", say the researchers.

Tartrate source The analysis revealed tartrates - a chemical concentrated in the seeds of grapes and hawthorn trees which are common in China. And indeed the only fruit seeds excavators reported finding at the Jiahu site came from these plants.

Although fermentation can occur naturally, wines must be sealed in containers to keep bacteria from converting the alcohol to vinegar. Jiahu is the oldest Chinese site with pottery - wood or leather containers would not have survived and so alcoholic beverage production could have gone even further back into Chinese history.

Patrick McGovern at the University of Pennsylvania Museum in Philadelphia, US, who led the study believes that honey, grapes and hawthorn fruit gave the Jiahu brewers the sugar and yeast they needed to start fermentation. Later Chinese brewers developed a technique called mould saccharification, which breaks the complex carbohydrates of rice into simple sugars that can be fermented. That process yielded more specialised drinks including ancient and modern rice wines.

Why brewing developed nearly simultaneously in east Asia and the middle east is something "we haven't resolved yet", McGovern told New Scientist. "The expanse of central Asia in between would seem to preclude any direct connection," he says, but more research may show links - or a common origin.

Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0407921102)