While sake kasu and sake wouldn’t exist without each other, don’t get it confused — they are most definitely not the same thing. Sake is the ubiquitous Japanese rice liquor, while sake kasu is the leftover lees that result from sake’s fermentation process. During the production of alcoholic drinks, fermentation creates a byproduct of residual particles that consist primarily of leftover yeast; these are the lees. In some drinks like certain wines or beers, lees are left in, but it’s more common for them to be filtered out. When this filtration occurs during the sake-making process, sake kasu happens!
Sake kasu, in turn, has many culinary uses. Its consistency ranges from relatively hard to loose and crumbly, and its aroma and taste is a little bit sweet, a little bit floral, and a little bit, well, sake-ish. Often it is used in pickling or as a flavoring agent, most commonly for stew or soup bases, marinades, or in crackers and other snacks, although its usage isn’t limited to those purposes and creative cooks will find it’s quite versatile.
Our sake kasu comes directly from one of the major sake brewers in Japan. We purchase freshly pressed sake kasu every new crop rice season between September and October. We sell both plain sake kasu as well as our very own marinated kasu in our seafood department. Our signature black cod kasuzuke uses the marinated kasu and is one of our most popular items.