Dashi is simmered soup stock made by dissolving in water the umami flavor components of katsuobushi — flakes of dried bonito — or other fish flakes, kelp, dried sardines, dried vegetables (such as dried shiitake mushrooms or soybeans), or other ingredients. Continuing on from our previous article about kelp-based dashi, food researcher Kubo Kanako gives us an explanation of dashi made from katsuobushi and other fish flakes.
Different parts of the fish give different katsuobushi flavors
What kind of dashi do you use when making clear suimono soups, miso soup, or simmered dishes? Where you live has a big influence on whether you use kelp, katsuobushi, dried sardines, or other types of dashi. Nevertheless, most would agree that katsuobushi is the leading kind of dashi.
Few households today shave their own katsuobushi, but you can obtain unshaven katsuobushi blocks at specialty stores and large dry food stores. “Katsuobushi can be classified from the part of the fish they are taken from: from the back, from the belly, and a smaller third type called kamebushi taken from the middle portion of the fish between the back and belly. Each type has its own flavor. The belly has more fat than the back, while the back is lighter in taste. You can think of them as being like fatty cuts and lean cuts of meat. Kamebushi is made from smaller bonito, so it has a lighter flavor with the taste characteristics of both the back and belly. I prefer the light, refined taste of back katsuobushi.” Japanese restaurants and high-end ryotei restaurants choose the type of katsuobushi that best compliments their cuisine.
Kubo buys katsuobushi blocks from a specialty store and has them shaved at the store. Given that it is difficult to shave katsuobushi on your own, she recommends you have a shop shave it for you to get the freshest and most flavorful katsuobushi.
▲Katsuobushi have different flavors depending on which part of the fish they come from: from left, kamebushi, belly, back
Arabushi and karebushi:
The two types of katsuobushi
Kubo commented that it’s surprising more people do not know there are two types of katsuobushi for making typical dashi stock: arabushi and karebushi.
“Arabushi is bonito that has had its head and entrails removed and then simmered, smoked, and dried. Karebushi is made by taking an arabushi block and spraying it with mold and drying it multiple times. Shaved katsuobushi dashi packages list either katsuo-no-fushi for arabushi or katsuo-no-karebushi for karebushi as their ingredients.”
A further classification for karebushi is how many times the block is sprayed with mold. Those sprayed twice with mold are called niban-kabi (second mold), and those sprayed three times are called sanban-kabi (third mold). And generally, those sprayed four or more times with mold are called honkarebushi, or true karebushi.
▲Products that use arabushi list katsuo-no-fushi as their ingredient (top), and products that use karebushi list katsuo-no-karebushi (bottom)
“The hardness, aroma, flavor, and umami of honkarebushi are enhanced through the repeated cycles of drying and spraying mold. The most distinctive traits, however, are the unique astringent aroma and rich flavor produced by applying mold. Everyone has their own preferences, but in my case, I think karebushi is best for dishes where you want to use the dashi flavor to your advantage, such as clear suimono soups or savory chawanmushi egg custard, and arabushi is better suited for miso soup or simmered dishes. In the Kansai region, many chefs prefer arabushi, which does not have too strong an aroma, or choose magurobushi [flakes made from tuna], which has a strong umami flavor but a faint aroma, instead of katsuobushi.
When asked whether people should use both arabushi and honkarebushi at home, Kubo replied: “Freshness is more important than whether you choose arabushi or karebushi. If you can use up both types while they are still fresh, then by all means use both types as appropriate. But for the average household, it’s probably better to decide which type you prefer and use it up as soon as you can.”
There is more than one way to shave katsuobushi, although different manufacturers use different names for the shaving methods. As a rule of thumb, thin, large hira shavings or finely shaved katsuobushi can be used both as dashi stock and as toppings. Thick shavings, called atsu shavings, are good for preparing boiled dashi that has a rich, flavorful punch, such as stock for udon or soba noodles. Thin, thread-like shavings, called ito shavings, are best for toppings. Choose the type of shaving that best suits the meal you are preparing.
▲Kubo: “Find the type and shaving method that suits your taste. But freshness is paramount, so use up your katsuobushi quickly. I recommend keeping packages refrigerated after opening.”
Deciphering packaging labels
When you read the label of a dashi package or pouch, you may find the word zatsubushi, which means it contains flakes of other fish besides bonito. What, in fact, does the term bushi [flakes] really mean?
“The different types of bushi, including katsuobushi, refer to fish that have been smoked. Some examples besides bonito include souda katsuobushi [flakes made from souda bonito], sardine bushi, horse mackerel bushi, and mackerel bushi. Some products add these different bushi to katsuobushi to create their own flavors. For example, the umami of souda katsuobushi is ideal for making thick, somewhat strong-tasting dashi for udon and soba noodles. Similarly, the dashi flavors of sardine, horse mackerel, and mackerel bushi can be combined with katsuobushi to create thicker dashi stock with more umami and bitterness.”
As Kubo explained, katsuobushi product packages have all kinds of wording, such as honkarebushi, sanban-kabi, and souda katsuo. When buying a pack of shaved bonito flakes or dashi, pay attention to the wording and be sure to get the dashi that’s right for your cooking.
