When brewing Saké, little goes to waste.
In the brewing process, the first significant aspect of potential waste is when the rice is milled. All of the rice that is polished away leaves a powder that is called nuka. The breweries commonly sell this nuka, which can be put to a variety of uses.
First, it may be used to produce a type of tsukemono, Japanese pickle, called nuka-zuke. A variety of vegetables, such as daikon, cucumber and eggplant, can be pickled in a paste of nuka and salt. The pickles can have a range of flavors for sour to salty. Curiously, Japan is the only country with a tradition of using nuka for pickling.
Second, it may be used in cosmetic products. Rice brain oil can be derived from the nuka and this oil has many benefits. It is though to contain a high amount of Tocotrienol, a natural form of Vitamin E. Rice bran is also rich in phytic and ferulic acids, which contribute to softer, more supple skin. Thus, numerous cosmetic products have been developed using nuka, especially for skin lotions and such.
In addition, a couple other uses for nuka include animal feed or even to make desserts.
The next significant amount of waste in the brewing process is after pressing, when the lees are left over. These lees are also known as kasu, and like nuka is often sold to other companies which will use it for many different purposes.
First, like nuka, kasu can be used for pickling, creating kasu-zuke. Second, kasu can be used for cooking, as a marinade or to add flavor. It can be added to many different foods, from ice cream to bread. You might see Saké kasu at a Japanese grocery store, and it might look like cheese or tofu. Third, like nuka, it too may end up as animal feed. Fourth, it might even be recycled and distilled into pure grain alcohol.
It is good to know that so little goes to waste. Have anyone of my readers eaten a dish made with nuka or kasu?