Glossary - Ingredients

Katsuobushi / Bonito Flakes


A preserved food with condensed umami that is indispensable in Japanese cuisine.  Delicious as a base for "dashi"

What is katsuobushi?

Katsuobushi / bonito flakes (かつお節 in Japanese) are preserved bonito made by boiling the fish and introducing a specific mold to mature it properly, then drying it out time and again. Katsuobushi is shaved thin, then used to make dashi, or eaten on tofu or white rice. Though previously sold in mass that each household would shave down using their own shavers at home, nowadays they are mostly sold in shaved form.

Nutrition facts

Bonito flakes are high in inosinic acid which is what is said to provide the umami flavor. As the raw ingredient is bonito, it is also high in protein.

How to storage: not to waste the ingredient

Store away from high heat and humidity. The flakes will start oxidizing from the moment the package is opened, so seal them in an airtight container and then keep in a refrigerator or freezer to preserve flavor.


Dashi broth made from bonito flakes is rich in protein. It can be reused as a flavorful seasoning, or furikake, sprinkled on rice.


When making dashi broth with bonito flakes, ensure the broth is cooked at over 85°C. Colder water will only serve to enhance the bitter flavors.

Cooking Basics

Dashi - how to make from kombu and dried bonito flakes

Ingredients (for 800 ml / 27 fl. oz. of dashi)

10 g (3 × 25 cm / 1.2 x 10 in.)
Katsuobushi/bonito flakes
20 g (0.7 oz.)
1000 ml (33.8 fl. oz.)


Soak the kombu in water for 30 minutes, then heat over medium heat. Just before the water comes to a boil, remove the kombu and turn off the heat. After a few minutes, add in the bonito flakes and allow to sit for 2 minutes.  Place a dampened paper towel over an all-purpose strainer and strain the dashi.

Dashi (bonito) prepared using a tea strainer

This method is convenient for preparing small amounts of dashi, such as soup for one person, ohitashi (boiled vegetables seasoned with dashi and soy sauce), sesame dressing, etc. Place dried bonito flakes (about 5 g /0.2 oz.) into a tea strainer and pour in 200 ml (6.8 fl. oz.) of hot water.

Dashi (bonito) prepared using a tea bag

When making simmered dishes, place about 15 g (0.5 oz.) of dried bonito flakes into a tea bag for 1000 ml (33.8 fl. oz.) of water, and add the tea bag in with all other ingredients to prepare deeply-flavored and savory simmered dishes.

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