Katsuobushi (鰹節 or かつおぶし), also known as bonito flakes, are dried shavings of katsuo (skipjack tuna or bonito, 鰹). Katsuobushi is one of the essential ingredients for the Japanese soup stock dashi (出汁), the foundation of Japanese cooking.
What Is Katsuobushi?
Katsuobushi (鰹節) are shavings of skipjack tuna or bonito, known as katsuo. It’s most commonly used to make dashi, an essential soup stock used in a wide variety of Japanese dishes. It’s extremely high in umami, which is due to its high inosinate content. Katsuobushi is made by boiling, dry-smoking, then introducing Aspergillus glaucus, a beneficial mold that triggers fermentation in the fish fillet. The finished product resembles hard, petrified wood through a months-long drying process.
Types of Katsuobushi
There are several types of katsuobushi, which are used for different purposes.
Hanakatsuo (花鰹)
Thin pale pink petals that resemble large wood shavingsSome contain dark meatCommonly used as a garnish
Karebushi (枯れ節)
Refers to katsuobushi that repeats the drying and fermentation process twiceLighter-colored shavings, with or without dark meatSuitable for making flavorful and aromatic clear dashiDarker shavings are suitable for miso soups, simmered dishes, and dressings
Honkarebushi (本枯れ節)
Refers to katsuobushi that repeats the drying and fermentation process is at least three timesMuch more complex and elegant in flavor and expensive compared to karebushi
Arabushi (あら節)
The most common type of katsuobushi that does not undergo fermentationIt has a strong smoky aroma with a slightly acidic flavorAll-purpose for making soups, sauces, and dressingsThe more dark meat, the stronger the flavor
Atsukezuri (厚削り)
Thicker shavings than HanakatsuoMore dark meat (a higher concentration of chiai, which produces a rich and robust dashiSuitable for making braised dishes
Itokezuri (糸削り)
Thinnest shavings, suitable as a garnish for salads and tofu
How To Store Katsuobushi
Traditionally, you would shave a katsuobushi into thin flakes on demand while cooking. It’s shaved using a tool called katsuobushi kezuriki (鰹節削り器), similar to a wood plane. However, you can choose the shortcut and buy good quality shaved katsuobushi without shaving it yourself. Katsuobushi is extremely sensitive to humidity, so properly store opened bags; otherwise, they will oxidize, and the color will become dull. To keep your katsuobushi fresh for longer, expel air from the bag, reseal, and store in a cool, dry, dark location. If the packages did not come in a resealable bag, immediately transfer them to an airtight container. If you live in a humid environment, store the bags in the freezer.
What Does Katsuobushi Taste
While it resembles wispy pieces of paper, it has an almost explosive, intense smoky flavor. The umami flavor is more meaty than fishy, and the aroma is smoky.
How To Use
The Japanese use these flakes to make dashi. Dashi is made by infusing umami-rich sources, such as kombu, shiitake mushrooms, dried iriko/niboshi, or katsuobushi in water. While you can make dashi with just katsuobushi, many recipes call for combining katsuobushi and kombu dashi for an umami-rich broth. Dashi is the backbone of many Japanese dishes. It’s also used to make rice seasoning. Okaka (おかか) is katsuobushi cooked with soy sauce, sake, mirin, and sesame seeds. You can mix the okaka into the rice or use it as a filling for onigiri rice balls. In addition to making dashi, it’s also used in other dishes, including:
OkonomiyakiTakoyakiSpinach OhitashiChilled TofuSimmered Bamboo Shoots (Tosani)Homemade Ponzu Sauce
Where To Buy
You can find bags of katsuobushi flakes at most Asian/Japanese supermarkets. Depending on how frequently you plan to use it and the purpose, you can choose to buy a large bag or smaller packets.
How To Pick The Best
The best quality katsuobushi has light pink or beige shavings that will be slightly shiny. Dull flakes mean poor storage and may have oxidized, so do check the contents before buying.
Substitutions
No substitution gives the same umami experience as katsuobushi. While you can make dashi with other ingredients, the taste will not be the same. While katsuobushi is rich in inosinate, kombu and shiitake dashi have glutamate, a different type of umami (for more on umami applied to Japanese cuisine, please read The Definitive Guide to Umami and Japanese Cuisine). If using katsuobushi as a garnish, you could use shredded nori, natural yeast, powdered mackerel, or different kinds of fish flakes as a similar umami-rich topping.
Health Benefits
Katsuobushi contains all the essential amino acids necessary for the body because it cannot produce them on its own and thus must obtain them through your diet. Among its many benefits, amino acids are fundamental for creating collagen, which keeps your skin supple. It is also rich in vitamins and minerals, including iron, niacin, and B12. Regular consumption of katsuobushi may help improve brain function, lower blood pressure, and boost metabolism. Also, it helps reduce the risk of several diseases, including dementia, heart disease, depression, and diabetes.
Q: Why does katsuobushi move with heat?
You may have noticed the katsuobushi flakes moving on top of hot foods, such as okonomiyaki or takoyaki. Rest assured, the fish spirit isn’t resurrected, it’s because the shavings are so fine and light, that they seem to “dance” on top of hot foods.
Q: How long does katsuobushi last?
If kept in a cool and low humidity environment with little exposure to air, katsuobushi should last for a few weeks. It’ll keep for longer if the bag is unsealed, as it’s most likely pumped with nitrogen. Taste a few whisps and check the color if it’s good to go before use. Wish to learn more about Japanese cooking? Sign up for our free newsletter to receive cooking tips & recipe updates! And stay in touch with me on Facebook, Pinterest, YouTube, and Instagram.
