Tips for Cooking with Bonito Flakes

One of the essential components in Japanese cuisine is katsuobushi or dried bonito flake. Katsuobushi, high in umami flavor, is used to make stock and a topping, garnish, and spice for everything from noodles to rice to eggs. The bonito is filleted and boiled before being smoked to make katsuobushi. After that, it goes through a fermentation and sun-drying process that can take months. To know the best tips for cooking with bonito flakes, read further.


Bonito Flakes Nutrition Facts

bonito flax nutrition facts

What are Bonito Flakes?

Bonito flakes, also known as katsuobushi, are smoked, fermented, and dried bonito or skipjack tuna flakes. After cleaning and filleting the fish, the producers simmer and smoke it for a month at a time before sun-drying it. A bacterial mold culture called Aspergillus glaucus is used to foster the growth of a protective mold that ferments the fish and absorbs any leftover moisture.

As the fish dries, the mold is scraped away and allowed to rebuild. Once the drying process is complete, the finished fish will resemble chunks of hard, petrified wood. Producers then shave the fish with a katsuobushi kezuriki, a sharp plane fitted into a wooden box. Commercially available katsuobushi is pre-shaved and packaged in a sealed bag; once exposed to oxygen, the shavings lose their airy shape and color, so it’s better to utilize them immediately. You can also keep katsuobushi in the freezer in between usage.

How are Bonito Flakes Made?

First, to make Bonito flakes, chop the fish into four pieces to make Fushi, the Japanese word for huge dried chunks. After that, the pieces are set out in a particular pattern in a basket and cooked for around two hours. The fish is then meticulously deboned using tweezers. After that, the boiled and boneless pieces are smoked, usually using cherry or oak wood. The tar and fat are scraped from the surface after smoking, and the Fushi is then sun-dried. The result is katsuobushi, a wood-like block that some claim is the world’s most challenging meal.

A particular shaver is used to shave the flakes off of this block. This procedure can take months and reduces the fish’s weight to around a sixth of its initial size. Bonito flakes add a burst of flavor to any recipe in need of it. This smokey umami aroma, albeit slightly fishy, gives the flakes their sensory fame. When you combine them with the edible kelp kombu, water, and other ingredients, you produce dashi stock, which is used to make miso soup and other broths, as well as okonomiyaki and takoyaki dough. They can also season noodle or rice dishes and other savory dishes.

4 Types of Bonito Flakes

Katsuobushi comes in a few distinct grades, each with slightly different applications:


Fish fillets must go through three steps to be categorized as katsuobushi: They must be boiled, smoked for at least one month, dried, and fermented for at least two weeks using a bacteria culture. Karebushi, or “dried fillet,” is katsuobushi that has been dried and fermented twice and has a depth of taste suitable for a dashi base.


If the drying and molding process is accomplished three times, the katsuobushi is classified as honkarebushi, or “genuine dried fillet,” if the drying and molding process is accomplished three times. This process is repeated by some high-end honkarebushi for years, resulting in a staggeringly intricate depth of flavor.


Hanakatsuo is katsuobushi flakes shaved into thin, pale pink flakes that are most typically used as a delicate, flavor-packed garnish.


These shavings are thicker than hanakatsuo and have a higher concentration of chili (dark meat shavings), making them suitable for injecting deep umami flavor into a sauce or braising liquid.

How to Use Bonito Flakes in Cooking?

Bonito Flaks

Dried bonito flakes can be used as a flavoring or garnish in various Japanese recipes. Here are some of its most common applications:

As a topping:

Bonito flakes are essential condiments for dishes like okonomiyaki, savory cabbage, egg pancake, takoyaki, grilled octopus balls, and additional ingredients like aonori (dried seaweed powder) and Japanese mayonnaise.

As a filling:

Okaka is a popular filling for onigiri, Japanese rice balls made from dried bonito flakes soaked with a little Shyu (soy sauce).

As a seasoning:

The significant spices in katsuo dashi, a traditional Japanese soup stock, are bonito flakes and kombu (dried kelp). Dashi is used as soup stock and a sauce basis in various cuisines, ranging from miso soup to ramen. Bonito flakes can also be ground into a powder and used to furikake to boost the umami content.

Are Bonito Flakes Healthy?

Here are some health benefits of bonito flakes:

  • Bonito flakes provide several health advantages. They contain essential amino acids and are high in protein, iron, niacin, and B12.
  • They may also improve brain health and metabolism and reduce the risk of heart disease and diabetes.
  • Bonito flakes can be eaten plain or used in various meals as a garnish, topper, or ingredient. However, making dashi (Japanese broth/soup stock) is one of the most common uses of bonito flakes in Japanese cuisine.
  • Even though bonito is a fast-growing skipjack tuna, it contains very little mercury.
  • However, Benzopyrene, considered carcinogenic, is present in bonito flakes due to smoking.
  • Because of the smoking procedure, the Japanese product contains exceptionally high quantities of Benzopyrene (a recognized carcinogen).
  • According to a study, katsuo dashi prepared from bonito flakes can help to alleviate brain tiredness and improve overall performance on simple calculations.
  • Bonito flakes may help promote mental health by improving blood flow or peripheral circulation. It may also improve emotional states and lower urinary oxidative stress marker levels.


The best ones will give you the best flavor when cooking with bonito flakes. Bonito flakes can be used as a substitute for whitefish in recipes. Bonito flakes are kosher-compliant in addition to being healthful. If you’re keeping kosher, you’ll want to be sure you’re using the appropriate kind of bonito. Bonito flakes are often light and will melt in your cuisine. They’re great for sushi since they give it a smokey flavor. They can also be used in soups. However, make sure you get the proper kind. You’ll be pleasantly surprised by the diversity of options available, regardless of the size of your family. Don’t forget to look at the ingredients as well as the pricing.