The history of sake is a rather long and mysterious one. Indeed, it is difficult to pinpoint precisely when the first-ever sake was made, and historians have various theories about its origin.
One of the oldest alcohol is believed to be wine. Its discovery happened when people who ate grapes left out in the open realised it had intoxicating properties that led people to feel more joyful (we've all been there). As it turned out, the yeasts, naturally present in the atmosphere, had converted the high sugar content of the grapes into alcohol.
Rice, like most grains, is mostly starch and does not have readily fermentable sugar. So if we leave a bucket of rice out in the open, no fermentation will happen as it will with grapes, and we'll waste some perfectly good rice.
So how did people first turn rice into alcohol? The answer is in your mouth. They first did it with their saliva.
Rice first made its way into Japan from China and South East Asia in the 3rd Century. At the time, the modern techniques to transform the grain into delicious sake as we know it today were far from being invented.
Researchers, however, have discovered that around the 8th Century, people would cook rice, chew it and then spit it into a tub. This mixture would then be left alone for a few days. The result had pleasurably intoxicating effects. This ladies and gentlemen, was the very first form of sake.
Why did people need to chew the rice? The amylase enzymes present in our saliva acted as the starter. It helped turn the rice starch into fermentable sugars. Sake made this way was called Kuchikamizake (kuchi = mouth, kami = chew, sake = alcohol), literally meaning "mouth chewed alcohol. "
This "chewing" technique was not unique to Japan but was widespread around the globe. For example, the South Americans were chewing up maize to make chicha and yuca to make Masato.
Culturally, the ruling class of Japan had taken some liberties and declared that the chewing of the rice should be done exclusively by women. The sake was then called bijinshu ("beautiful woman sake"). Making women the first sake brewers!