During Old Stone Age Period, wild fruits were a staple food. These contain much natural sugar; and under the action of microorganisms, the sugar easily turns into alcohol when fermented. Animals’ milk contains protein and milk sugar that likewise easily turns to alcohol. At the same time, ancient hunters might have chanced to get animal milk. The alcoholic drink called lilao recorded in The Yellow Emperor’s Cannon of Internal Medicine is a kind of sweet milk and might be the earliest milk wine.

Some ancient Chinese books have recorded matters relating to fruit wine production through the natural fermentation of fruit. Kui Xin Za Zhi by Zhou Mi of the Song Dynasty says that mountain pears stored by local people in urns turned to alcohol. The preface to Pu Tao Jiu Fu by Yuan Haowen of the Yuan Dynasty says that a certain person who lived near a mountain ran away from the ravages of war and sought safety in the mountains. In his house was a pile of grapes stored in an urn. When fermented, the grape juice turned to alcohol under the action of the natural sugars of the grapes.

This article by Yang Tianqing and Daniel Kister.