You might not realize it, but that can of “light tuna” found on your local grocer’s shelf holds an ingredient that is an essential part to Japanese cuisine as we know it: skipjack tuna, which is also known as bonito or, in Japanese, katsuo鰹かつお. If you have ever been to a Japanese restaurant you probably have tasted the wonderful umami taste that katsuo gives to many Japanese dishes, including the humble and ubiquitous miso soup. Umami is the fifth sense of taste. The savory sensation created by umami is caused by glutamic acid, inosine acid, and guanylyl acid, which can be found in many foodstuffs. Japanese cuisine makes use of umami flavor through many ingredients.

Japanese dashi出だ汁し, a kind of soup stock, is made by simmering or steeping ingredients to bring out their umami flavor. Some of the most common dashi ingredients are katsuobushi鰹かつお節ぶし, konbu昆こん布ぶ kelp, niboshi煮に干ぼし dried sardines, and dried shiitake mushrooms, which can be used separately or in combination with one another to create different flavor profiles. It is this dashi, and the umami flavor imparted by these ingredients, that in effect defines the archetypical flavor of even the most quintessential Japanese dishes.

Of the ingredients used to make dashi, katsuobushi is the most common. Katsuobushi is made by repeatedly smoking and drying boiled deboned filets of katsuo. The result is a hard, wood-like block of smoked fish that has been recognized by Guinness World Records as the hardest food in the world. Traditionally, katsuobushi was shaved by hand to create flakes that could be steeped in hot water to create dashi.

There are two types of katsuobushi: honkarebushi本ほん枯かれ節ぶし and arabushi荒あら節ぶし. The former, honkarebushi, is inoculated with a culinary mold that was found to enhance its flavor profile. This discovery was made after the mold grew on katsuobushi that was shipped from southern Japan to Edo, present day Tokyo. Due to its more subtle flavor profile, honkarebushi is considered a premium product and is often preferred when making clear stock and for highlighting the delicate flavors of other ingredients. Arabushi is commonly used in dishes like nikujaga肉にくじゃが, a simmered dish made with meat and potatoes, which require a more robust stock that can compete with the other strong flavors found in the dish. Katsuobushi is also used on its own as a common topping for rice and dishes like okonomiyakiお好このみ焼やき.

Katsuobushi has found its way into many dishes and today is enjoyed by people around the world. Take for example one of the dishes presented in the Japan National Tourism Organization’s Discover Japan Recipe Campaign, where katsuobushi is used to provide some extra umami flavor to a delicious looking seared tuna dish. Follow the link below to learn more about the Discover Japan Recipe Campaign and the chance to win a trip to Japan.