Katsuobushi is a traditional Japanese ingredient made from dried skipjack tuna. The dried fish is processed into flakes to be used as a condiment or as the flavoring base to make other dishes. It is often paired with dried seaweed to flavor a variety of authentic Japanese dishes and give them a distinctive taste.
The process of making katsuobushi generally begins by soaking fillets of skipjack tuna in boiling water to soften the fish and cook through the flesh. The boiled pieces of fish are then smoked for up to 20 days until they have an extremely hard texture. They may then be further dried in the sun. The entire process may be repeated multiple times to ensure a texture which is as hard as possible. These hardened pieces of fish are then grated or very thinly sliced to make rough flakes, similar to the texture of wood shavings.
One of the most traditional uses of katsuobushi is to make dashi. Dashi is a traditional Japanese broth that often forms the basis for the majority of soups, sauces, noodle dishes, and other Japanese entrees and condiments. It is made by boiling dried skipjack tuna flakes and dried seaweed flakes in hot water for an extended period of time. Once the fish and seaweed have boiled long enough to flavor the water, the solid pieces are removed from the mixture and the remaining broth is used for Japanese dishes. One of the most common uses of dashi is for miso, a soup made from dashi and bean, rice, or barley paste.
In Japanese cuisine, katsuobushi is also often used as a condiment or topping. The dried skipjack tuna flakes may be drizzled with soy sauce to add moisture and flavor. They may be sprinkled onto noodle, tofu, or rice dishes. The fish flakes are also often combined with sesame seeds or nori, sheets of dried and flattened seaweed, and served as garnishments.
When katsuobushi flakes are combined with steam, they may quickly move around. This tends to occur most often when they are sprinkled onto soups or other hot entrees. Due to this sudden movement, the dried skipjack tuna flakes are also commonly referred to as dancing fish flakes.
Commercial katsuobushi flakes are generally available in two main textures: thick and thin. The thick version of the flakes tend to have a stronger fish flavor and are more often utilized for making dashi broth. Thin fish flakes are typically purchased more often for toppings and condiments because they have a softer texture that many may find more palatable.