Seven thousand years ago, people living on Pingtan Island off the southeastern coast of China gathered shellfish, worked with plants, made pottery, and drank something archaeologists can no longer pour into a glass.
The liquid disappeared long ago. But microscopic starch grains, yeast, and mold remained trapped inside ancient pottery. Their damage patterns suggest that people at the Xiying shell midden were fermenting a drink made primarily from rice, along with millet, tubers, seeds, and other plants, using an early form of qu fermentation.
The discovery reveals more than an ancient drink. It may preserve the movement of knowledge between coastal communities long before writing recorded who taught whom.