The exact origin of sake is unclear because it predates recorded history, but the earliest known production of sake took place in Japan roughly around 300 BC with the start of rice cultivation.
The sake making process is now done by machines but in the past, the process was crude; villagers would gather to chew rice and nuts and spitted the contents into a communal tub which would then be stored and left to ferment. The process is called kuchikami no sake meaning 'chewing in the mouth sake'. In the better grades of kuchikami no sake, only virgins were allowed to chew on the rice. Perhaps for the best, this method was soon abandoned after the discovery of koji, a mold enzyme that could be added to rice to begin fermentation. This brewing technique is believed to have spread throughout Japan in the Nara period (710 to 794), resulting in sake as we know it today.