What is Bonito?

Bonito is a crucial fish ingredient in Japanese cuisine, and a fundamental component of many stocks and sauces. It is readily available in Asian markets in the form of flakes or pellets which are designed to be dissolved in water or rice wine, and some types of dried bonito also come with flavorings like seaweed flakes and spicy chili power. Bonito is also sometimes listed or labeled as katsuobushi.

Fish in the genus Sarda, in the mackerel family, are used to make bonito, along with other similar species like skipjack tuna. The fish are also known as bonitos in Japan, and have long sleek bodies with forked tails and a series of smaller fins between the dorsal and tail fins. In addition to having culinary value, bonitos are also appreciated for the sport they offer, and are found in all major oceans. Bonito can also be eaten fresh, and is sometimes sold canned along with other members of the tuna family.

In Japan, bonito season is in the early spring, when the fish school off the shores of Japan, remaining there until fall. Bonitos are harvested in large numbers before being boiled whole and cut in half. The bones and skin of the fish are removed, and the split fish are smoked and dried, traditionally in the sun. The fish are smoked and dried repeatedly until they form solid brown blocks of fish, which can be sold whole or flaked.

Bonito used to be sold whole until the 1970s, when commercial fisheries began flaking the fish for ease of use. Before this period, cooks would shave chunks of the fish off as needed, periodically removing the mold which would accumulate on the outside of the fish. Some cooks still prefer whole bonito, claiming that the flavor is superior to that of flakes. The flakes do have a greater tendency to dry out and lose flavor, and should be stored in a dark, cool, dry place in tightly sealed containers.

Bonito is one of the primary ingredients in dashi, the Japanese soup stock which is the basis of miso soup, liquids for simmering various foods, broth for noodles, and some sauces and marinades as well. Dashi is made by boiling bonito and flakes of seaweed in water and then straining the resulting liquid, leaving a rich, salty broth behind. Many other Japanese recipes call for this vital seafood ingredient, and cooks who would like to maintain a library of Japanese seasonings should obtain bonito or pre-mixed dashi powders.