Sakekasu Amazake and Kasujiru Lees Applications

Japan — sake brewing regions: Nada (Kobe), Fushimi (Kyoto), Niigata, Akita; kasu utilisation documented from Edo period

Sake kasu (sake lees) — the solid residue remaining after pressing fermented rice moromi to extract sake — is a deeply nutritious, complex ingredient with multiple culinary applications. Rich in living koji enzymes, amino acids, vitamin B complex, and residual alcohol (typically 8–14%), sake kasu adds depth, body, and sweetness to preparations ranging from fish marinades to winter soups. The three primary applications: kasujiru (kasu soup), a winter warming broth of sake kasu dissolved in dashi with root vegetables and salmon; kasuzuke (kasu-marinated fish), where fish is buried in kasu paste with salt and sugar for days to weeks; and amazake (sweet kasu drink), where kasu is dissolved in hot water with sugar for a nurturing traditional drink. Unlike shio koji, sake kasu adds more body, alcoholic depth, and sweetness.

• Both sake kasu and wine marc represent the enzymatically active lees byproduct of fermented grain/fruit pressed for beverage production, used in secondary culinary and distillation applications → Wine marc (pomace) cooking and grappa production European
• Both traditions use rice wine lees as flavour-enriching cooking ingredient, with fermented grain byproduct adding body, sweetness, and complexity to preparations → Makgeolli (rice wine) lees jeon pancakes Korean

Mellow alcoholic warmth, rich sweetness, complex fermented rice depth, enzymatic umami, caramelising sugars under heat