Amazake is a traditional sweet, low-alcoholic Japanese drink made from fermented rice. Amazake dates from the Kofun period, and it is mentioned in the Nihon Shoki. It is part of the family of traditional Japanese foods made using Aspergillus oryzae (麹, kōji) that includes miso, soy sauce, and sake.
The basic recipe for amazake has been used for hundreds of years. Kōji is added to cooled whole grain rice causing enzymes to break down the carbohydrates into simpler unrefined sugars. As the mixture incubates, sweetness develops naturally.
Amazake can be used as a dessert, snack, natural sweetening agent, baby food, salad dressing or smoothie. The traditional drink (prepared by combining amazake and water, heated to a simmer, and often topped with a pinch of finely grated ginger) was popular with street vendors, and it is still served at inns and teahouses. Many Shinto shrines provide or sell this in the New Year. In the 20th century, an instant version became available.
Amazake is believed to be very nutritious, with no additives, preservatives, added sugars or salts. Outside of Japan, it is often sold in health.
(Definition from Wikipedia)