One compelling aspect of Saké brewing is that there is so little waste. When the rice is polished, it leaves a powder behind which is called nuka, but that nuka is not discarded. Instead, it is soldand will be used for a variety of purpose, from pickling to cosmetics.
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.
It might be used for animal feed or in pickling, creating kasu-zuke. Plus, 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. A recent Washington Post article, Kasu: the next "it" ingredient?, discusses how a couple chefs are using it in the U.S., and how it could become a very popular ingredient in the future.
It is an ingredient you might find in some of the local Asian grocery stores. Have any of my readers used in in cooking? If so, please tell us more about your experiences with it.