|The bonito, a member of the mackeral family of fish, has been a mainstay in the Japanese diet for centuries. Once bonito's ability to preserve well was discovered in the fifteenth century, it became highly treasured by samurai warriors as a field ration.
To make dried bonito (katsuobushi), the fish are filleted and cut lengthwise into quarters. After being steamed, sun-dried, and wood-smoked several times until they are thoroughly dried, the fillets are placed outdoors on racks for about three months to ferment. This ancient method, which uses natural fermentation to increase bonito's nutritional values is still used today.
Once fully mature, the dried fillets will maintain their quality almost indefinitely if kept cool and dry. The bonito fillets are shaved into flakes on a katsuo kezuri-ki (bonito shaver) just before use. Bonito flakes also come prepackaged in small, convenient cellophane envelopes that preserve their freshness well. These "single serving" packets of shaved bonito are much preferred over large bags or boxes, in which the flakes rapidly lose their flavor and quality.
Bonito is valuable whenever a mild fish flavor is appropriate. It is most commonly used along with kombu sea vegetable in making a flavorful stock for various types of soups and noodle broths and for simmered root vegetable dishes. Following is a recipe for Kombu-Bonito Stock (Dashi). Once the stock is prepared, other ingredients, such as miso or shoyu and mirin are added to create a variety of different tastes.
6-inch piece kombu
4 cups cold water
1 cup bonito flakes
Place kombu and water in a saucepan and bring to a simmer, uncovered, over medium heat. After simmering briefly, remove kombu and reserve it for another use. (It may be reused to make soup stock or cooked with beans or vegetables.) Stir bonito flakes into stock, then remove pan from heat and let sit for 2 minutes. Strain the broth, pressing liquid from the flakes with the back of a spoon.