Amazake is a traditional Japanese beverage made by fermenting rice to yield a sweet and nutritious drink. The fermented beverage can be found in specialty stores and health food stores, since it has high nutritional value. For people with lactose intolerance, amazake is an excellent milk alternative, and it can be used in a wide variety of dishes in addition to being consumed plain.

To make amazake, rice is saturated in Aspergillus oryzae, a type of fungus. The fungus is also known as koji, and it is a crucial ingredient in Japanese fermented foods such as sake, soy sauce, and mirin. After the fungus has taken, the rice is mixed with freshly cooked rice and allowed to incubate at a temperature of around 130 degrees Fahrenheit (55 degrees Celsius) for approximately 14 hours. The koji breaks the starches in the rice into sugars, and the incubation is halted before the sugars can convert into alcohol. The mixture resembles porridge at this point, and it is usually pureed before sale.

After being pureed, amazake is extremely thick, and it resembles pudding. It can sometimes be found available in this form, and it is also sold diluted, as a fermented liquid. Some companies add flavorings such as vanilla or chocolate, especially for markets outside of Japan. Without stabilizers, amazake is very perishable, so it should be kept under refrigeration and used quickly.

In Japan, amazake is often served warm with a pinch of grated ginger. It can also be used in desserts, added to smoothies, or used as a milk alternative in other dishes. The beverage has a sweet, slightly fermented flavor which reminds many people of sake. The similarity in flavor is unsurprising, since amazake is closely related to sake. In fact, some sake companies distill leftovers from their brewing process to make a type of amazake, making efficient use of all of their ingredients.

People sometimes compare amazake to rice milk or other grain milks. The process for making grain milks is similar, but amazake is fermented and grain milks are not, as a general rule. Both can be made at home, although making amazake is somewhat trickier, since cooks want to avoid the promotion of unwanted bacteria. Koji is available from several companies, often in the form of rice flour inoculated with the fungus. Either brown or white rice can be used to make amazake, and cooks should wash the rice scrupulously first.