The earliest evidence of winemaking comes from the South Caucasus region, specifically in modern-day Georgia. Archaeologists discovered clay jars (called Qvevri) containing residual tartaric acid, dating back to 6000 BC. In this ancient method, grapes were crushed and then buried in the large clay vessels to ferment underground during the winter months. This produced a natural wine, often amber in color. The practice spread to the Fertile Crescent, Egypt, and Greece, where wine became central to religious and social life. The Greeks even had a god of wine, Dionysus. Winemaking was later perfected by the Romans, who introduced the use of wooden barrels for storage and transport, a technology they borrowed from the Gauls.