When sake is pressed, the liquid runs off and the solids stay behind — rice, koji and yeast that still hold a great deal of flavor. That is sake kasu (酒粕). Breweries sell it in winter, during and after the brewing season, and cooks have been using it for centuries.
Three forms
- 板粕ita-kasu · sheet kasu
- Pressed into flat sheets. Firm; soften it in a little warm water or sake before using.
- バラ粕bara-kasu · loose kasu
- Broken pieces from pressing. Easy to measure and dissolve.
- 練り粕neri-kasu · paste kasu
- Kneaded and rested until soft and paste-like, often darker and deeper in flavor. The one for marinades and pickles. Long-aged versions are called 踏み込み粕 (fumikomi-kasu).
Four lives
粕汁 — kasu-jiru
A warming winter soup: dashi with root vegetables, a little fish or pork, and kasu stirred in at the end. Dissolve the kasu in some of the hot broth first so it doesn’t clump.
粕漬け — kasuzuke
A marinade for fish — salmon and black cod are classics. Mix kasu with white miso and a little mirin, coat the fish, and rest it in the fridge for a day or two. Wipe off the marinade and grill gently: it browns fast.
甘酒 — amazake
Kasu dissolved in hot water and sweetened, often with a little grated ginger. Note: kasu amazake contains some alcohol. Amazake made from koji is a different drink and is alcohol-free.
Beyond Japanese food
Kasu brings a savory, slightly fruity depth — think of it like a cheese or a miso. Blend a spoonful into cream cheese for a dip, into a salad dressing, or into butter for roasted vegetables.
Storing it
Keep kasu in the fridge, wrapped tightly. It also freezes well. Over the months it slowly darkens and deepens — that is aging, not spoilage — but discard it if you see mold.