Amazake Recipe: How to Make Japanese Fermented Rice Drink

Amazake ("sweet sake") is a Japanese beverage made from rice and kome koji (rice koji), or rice inoculated with Aspergillus oryzae, the same mold used to make other fermented foods like miso, mirin, and soy sauce. Amazake is the first step to making sake, but it can be enjoyed on its own as a non- or low-alcoholic, sweet beverage.

Koji produces enzymes (made up of amino acids) that break the starch (carbohydrates) in rice down into the sugars glucose and oligosaccharides, resulting in a sweet drink. If left to ferment for more than a day or two, lactic acid bacteria will start to turn the amazake sour, and eventually, the sugars will break down into alcohol, producing the familiar fermented beverage sake.

When it comes to making homemade amazake, there are two main routes: koji and sake lees.

1. 1. Amazake made with koji: Amazake made with koji is more traditional. The process takes a little longer and requires several hours of incubation at a precise temperature. It does not typically contain alcohol.
2. 2. Amazake made with sake lees: Amazake made with sake lees is a little easier to make provided you have access to sake lees—a byproduct of sake production. You simply mix steamed rice with sake lees to achieve an amazake-like beverage. Amazake made with sake lees does contain alcohol.

A version of amazake is first mentioned in Nihon Shoki (Chronicles of Japan), an old Japanese text compiled in 720. During the Edo Period (1600–1868), amazake was served during the summer to prevent fatigue. Today, it is typically enjoyed during New Year and Hina Matsuri (Girl's Day or Doll Festival) celebrations.

This fermented rice drink is relatively easy to make. All you need is Japanese rice and koji, which can be found online and in many Japanese and health food grocery stores sold dried or frozen.

1. 1. Cook the rice. Prepare steamed rice in a rice cooker. White rice will yield a sweeter drink, but some people prefer brown rice for its nutritional benefits. Amazake can be made with regular steamed rice and then diluted, or rice cooked on the porridge setting of the rice cooker, no dilution needed.
2. 2. Add the koji. Let the rice cool slightly (to about 140 degrees Fahrenheit) before adding the koji. Once the rice has reached the ideal temperature, you can add the koji, or mold-covered rice. The more koji you use, the sooner your amazake will be ready. Ratios range from two parts koji to one part rice, to one part koji to two parts rice.
3. 3. Incubate the koji and rice mixture. Amazake needs to be kept within a precise temperature of 131 to 140 degrees Fahrenheit. You can achieve this using a yogurt maker, thermos, or immersion circulator (sous vide). The easiest method is to leave your rice cooker on the "keep warm" setting with the lid off and the amazake covered with a clean kitchen towel for eight hours.
4. 4. Serve the amazake immediately. You can slow fermentation by keeping the amazake in the refrigerator, but it will eventually start to transform into sake. Another method to stop fermentation is to boil the amazake, which actually kills the koji enzymes.

Amazake contains high levels of vitamin B1, vitamin B9 (folate or folic acid), glutamine, and probiotics. Amazake made with brown rice may be a source of dietary fiber. It's also naturally gluten-free.

Amazake has the texture of rice porridge, so you can add sweetener and eat it like a pudding, but it's typically served as a drink. You can drink it as a hot beverage diluted with water. Some people prefer to blend their amazake for a smoother texture, while others enjoy the rice grains floating in the beverage. You can also blend it as a smoothie with fruit and soy milk. Mix it with sake or sake kasu (sake lees) for an alcoholic beverage.