What is Sake Kasu?

Kasu, also known as sake lees, is the byproduct left after the production of sake. During the brewing process, the rice is fermented, and the liquid is separated from the solid components, which includes the leftover rice solids and yeast. These rice solids, known as sake kasu, have a rich, slightly sweet flavor and are packed with nutrients, such as amino acids, vitamins, and minerals. Traditionally, kasu has been used in various Japanese culinary applications, including in marinades, soups, pickles, and even desserts. Koji in the kasu also produces various acids, which can be used to tenderize meat. Kasu’s high moisture content and slightly pungent, fermented taste make it a versatile ingredient that enhances the umami flavor of many dishes.

In addition to its culinary uses, sake kasu has gained recognition for its potential health benefits. It contains microorganisms from the fermentation process, which may support digestive health and improve the gut microbiome. Furthermore, sake kasu is rich in antioxidants, which can contribute to overall wellness. Its use in skincare products has also become popular, as some believe it can help brighten and hydrate the skin due to its moisturizing properties. After Kasutori Shochu is made from the distillation process, the now de-alcoholized kasu is usable in a variety of agricultural uses, including animal feed and fertilizer. Whether incorporated into food, cosmetics, or farming, sake kasu is a valuable and sustainable resource.