Katsuobushi, also known as bonito flakes, is a type of dried, fermented, and smoked skipjack tuna that is widely used in Japanese cuisine. It is a key ingredient in umami-rich dashi broth, which forms the foundation of many Japanese dishes.
Production is a labor-intensive process that can take several months. Fresh skipjack tuna is boiled, smoked, and left to dry in the sun over an extended period; during drying, the tuna is inoculated with a specific mold (Aspergillus glaucus) that breaks down proteins and develops the distinctive flavor and aroma. The dried tuna is then shaved into thin, delicate flakes using a specialized tool called a katsuobushi kezuriki.
Katsuobushi is prized for its intense, savory flavor and aroma, often described as smoky, nutty, and umami-rich. It is used in dishes such as miso soup, nimono (simmered dishes), and takikomi gohan (seasoned rice), and the flakes are often used as a garnish for their delicate, fluttering texture and burst of flavor.
Katsuobushi is considered one of Japanese cuisine's foundational umami ingredients. Makurazaki in Kagoshima Prefecture and the Tosa region of Kōchi Prefecture are among Japan's best-known katsuobushi-producing areas, each with its own traditional production methods.
Katsuobushi is versatile beyond dashi: it can be sprinkled over rice, used as a topping for salads, or incorporated into sauces and marinades.