Japan — kasujiru tradition strongest in sake-producing regions: Nada (Hyogo), Fushimi (Kyoto), Niigata, and Akita; winter soup tradition aligned with sake pressing season (November-February)
Kasujiru (粕汁, sake lees soup) is a warming winter soup made with sake-kasu (酒粕, the pressed lees from sake production) combined with root vegetables and often pork or salmon to create one of Japan's most distinctively flavoured cold-weather preparations. Sake-kasu is the solid by-product of sake pressing — containing residual starch, proteins, amino acids, alcohol (8-14% by weight), and a complex flavour profile derived from the sake's fermentation history. Mixed with dashi or water and seasoned with a small amount of miso or salt, sake-kasu transforms into a rich, creamy, subtly alcoholic soup base with an earthy, yeasty depth that no other ingredient can replicate. The soup is thickened naturally by the starch content of the lees, giving it a viscous, coating quality ideal for warming from the inside out. Traditional kasujiru ingredients: daikon, carrot, gobo, konnyaku, salmon or pork belly, and miso in varying proportions by region. Kansai regions favour salmon (sake/shake) kasujiru; northern regions (Akita, Niigata) use local vegetables and pork. The alcohol content of sake-kasu means kasujiru is technically not appropriate for those who cannot drink alcohol — something to note when serving. Sake-kasu is available fresh from sake breweries in winter and early spring.
Sweet, earthy, yeasty depth from sake-kasu; slight warmth from residual alcohol; root vegetables provide structural sweetness; salmon or pork adds savoury richness; miso provides fermented salt notes; one of the most warming and complex Japanese winter soups
{"Sake-kasu dissolution: dissolve in warm dashi or water gradually — adding directly to cold liquid creates lumps","Alcohol content: sake-kasu retains 8-14% alcohol; simmer briefly to reduce, not eliminate, the alcohol","Root vegetables should be cooked first: add kasu only in the final minutes to prevent protein coagulation from overheating","Miso addition: small amount of miso alongside kasu adds depth; too much obscures the kasu's character","Seasonal timing: sake-kasu is most available and fresh January-March following winter pressing season","Protein choice: salmon contributes complementary fatty richness; pork belly adds savoury depth to the sweet-earthy kasu"}
{"Sake-kasu preparation: dissolve in small amount of warm water first, then add to the soup pot","Kasu boards (ita-kasu): fresh sake-kasu from breweries sold in flat boards — slice what is needed, store remainder refrigerated","Kasuzuke application beyond soup: sake-kasu marinade for salmon, pork, or vegetables produces the same sweet-earthy character","Final seasoning: taste before adding miso — the kasu provides significant salt and umami on its own","Umami layering: niboshi or konbu dashi base amplifies the kasu's natural amino acids for deeper soup"}
{"Over-boiling after adding sake-kasu — alcohol volatilises excessively and proteins coagulate, creating grainy texture","Not softening sake-kasu before adding — hard lumps that don't dissolve create uneven texture","Using stale sake-kasu — best fresh; older lees develop excessive sourness that dominates","Under-seasoning — sake-kasu's sweetness requires balancing with enough salt or miso","Serving immediately — allowing kasujiru to rest 5 minutes allows root vegetables to absorb the kasu flavour"}
Tsuji Culinary Institute — Japanese Soups and Winter Warming Foods