While WWOOFING on a rice farm near Osaka, Japan, our host Shigemi taught us how to make Amazake, a sweet fermented rice drink which was apparently used as a remedy for summer fatigue as early as in the Edo period. The boost provided by the drink has been compared to an IV drip. And, because the sweetness of the drink is entirely from the fermentation process itself rather than due to any added sweeteners, it can be used as a sugar substitute. (See Grainnaisance and Bittersweetblog for a few recipes using Amazake as a sweetener)
How to Make Koji Rice
At the heart of Amazake is koji -- the essence of Japanese food at large because it is the same rice-based fermenting agent used to make sake, soy sauce, and miso.
Making your own koji rice is a highly involved 2-day process. For the committed, check if your local Japanese specialty store sells koji spores (picture of a packet on the right) or else order them online at GEM Cultures. Then follow these step-by-step instructions on how to make your own koji rice on Everything 2. Alternatively, Vision Brewing sells koji-seeded rice and instructions how to use it to "koji-fy" a larger batch of rice for use.
How to Make Amazake
Use 2 portions of Japanese short-grain rice for every 1 portion of koji. Also, have a thermometer handy.
- Use 5-7 cups of water for every cup of regular rice
- Cook the regular rice until it becomes porridge (40-60 minutes)
- Cool the porridge until it reaches between 50 deg C and 60 deg C
- Mix koji into the porridge thoroughly
- Keep the mixture between 50 deg C and 60 deg C for 10 hours (If using a rice cooker, use the “keep warm” function, and keep the rice cooker lid open if the mixture needs cooling)
- NOTE: If mixture spend an extended period at more than 60 deg C, it won't become sweet. If below 50 deg C, the mixture becomes sour
- During the 10 hours, stir the mixture thoroughly every 2-3 hours. Wash mixing spoon with boiling hot water before stirring the mixture. This kills off any germs
- After 10 hours, the mixture is sweet
To Serve Amazake as a hot drink...
- Mix a 1 portion of water for every 1 portion of fermented ice mixture
- Bring the mixture to a boil, and let boil for 5 minutes
- Add a pinch of salt and grated fresh ginger to the mixture to taste
Refrigerate the boiled mixture above to serve as a refreshing cold drink, or freeze it to serve as a sherbet-like dessert!