Amazake

Amazake is fermented sticky rice (culture: koji) and turns the rice into a pudding-like mush. The bacteria breaks down the starch in the rice so amazake has a tooth-numbing sweetness.  As such, it is often used as a sweetener in recipes as a tremendously healthier alternative to white sugar, instead of eaten on its own.  When the amazake is ready it will be very sweet, and to maintain this taste it must be stored in the refrigerator.  If it continues to ferment at a warm temperature, the sugar will be converted into wine and produce rice wine.  Even further fermentation will convert the rice wine into rice vinegar.