Kasu-jiru is a traditional soup widely enjoyed in the Kansai region, where many sake breweries have historically been located. It is made with sake lees, a byproduct of Japanese sake production, combined with miso to create a rich and warming soup.
Typical ingredients include root vegetables such as daikon radish and carrots, together with fish such as salmon or yellowtail. In Kansai, pork is also a popular addition. Aburaage (deep-fried tofu) and atsuage (thick fried tofu) also pair well with the soup.
There is no single fixed recipe for kasu-jiru. The ingredients and preparation methods vary considerably depending on the region, household, and cook, making it a flexible example of traditional Japanese home cooking.
Kasu-jiru is particularly associated with winter because sake lees contain nutrients such as vitamins, carbohydrates, and amino acids. Sake lees are traditionally believed to have a warming effect on the body, making this hearty soup especially suitable for cold weather.
For this reason, kasu-jiru has long been served at winter events and seasonal gatherings in areas with a strong sake-brewing tradition.
One traditional account connects the development of kasu-jiru with January 20, a day marking the end of the New Year period in traditional Japanese seasonal customs.
Fish bones and heads left over from meals were used to make a flavorful stock, while sake lees produced during sake brewing and miso were added together with available leftover ingredients. This practical approach allowed food to be used efficiently while creating a nourishing and satisfying soup.
With its combination of sake lees, miso, vegetables, fish, and meat, kasu-jiru reflects the resourceful and seasonal character of Kansai home cooking. Its rich aroma and warming character make it a distinctive local dish to discover when exploring Osaka and the wider Kansai region.
For travelers interested in traditional Japanese comfort food, kasu-jiru offers an authentic taste of the food culture that grew alongside Kansai’s long history of sake production.