Bonito dashi is a basic Japanese stock made from katsuobushi (dried bonito). With its delicate aroma and umami, it supports the flavor of many Japanese dishes, such as miso soup, clear soup, and chawanmushi.
At the same time, some people outside Japan may wonder whether dashi made from katsuobushi, which comes from fish, tastes fishy. Katsuobushi does have its own distinctive bonito aroma, but that does not necessarily mean it tastes fishy. How that aroma and umami come out depends on the type of katsuobushi, how it is shaved, and how the dashi is made.
In this article, we introduce how katsuobushi is made and its different types. Then we share our recommended way to make dashi and how changing the method affects the aroma and flavor, along with the results of our own taste comparison.
Table of Contents
What Is Katsuobushi?
Katsuobushi is a Japanese ingredient made by boiling bonito, then smoking and drying it. Once it has lost most of its moisture and turned hard, it is shaved and used to make dashi or sprinkled over dishes.
Katsuobushi contains an umami compound called inosinic acid. When it is combined with glutamic acid, which is abundant in kombu (kelp), the two work together and the umami tastes even stronger. This is why kombu and katsuobushi are often combined to make dashi, as in chawanmushi.
Katsuobushi also has its own distinctive bonito aroma. However, having a fish aroma is not the same as having an unpleasant fishy smell. Whether that aroma comes out pleasantly depends on the type of katsuobushi, how it is shaved, and how the dashi is made.
Types of Katsuobushi
There are many ways to classify katsuobushi. Here we introduce three: by production (arabushi, karebushi, and honkarebushi), by part of the fish (sebushi and harabushi), and by shaving style (thick, thin, and powdered). Knowing these differences makes it easier to understand the differences in the aroma and flavor of dashi.
By Production: Arabushi, Karebushi, and Honkarebushi
Arabushi (荒節)
Bonito that has been boiled, smoked, and dried. Smoking reduces the moisture and creates the toasty aroma that is characteristic of katsuobushi.
Karebushi (枯節)
Arabushi whose surface has been trimmed, then finished by repeatedly applying beneficial mold and drying it. The mold is said to further reduce raw fishy odors. Under Japan's labeling rules for shaved katsuobushi (the Fair Competition Code), karebushi is defined as katsuobushi that has been molded at least twice.
Honkarebushi (本枯節)
Katsuobushi that is molded and dried even more times and finished over a long period is generally called honkarebushi. However, how karebushi and honkarebushi are named and distinguished may vary by maker and product.
In general, arabushi has a strong smoky aroma and a distinct bonito flavor, while karebushi and honkarebushi have a mellower aroma and a cleaner, rounder flavor. Neither is better than the other. Each has its own appeal, from the bold, toasty aroma of arabushi to the mellow flavor of karebushi and honkarebushi.
By Part of the Fish: Sebushi and Harabushi
When katsuobushi is made from large bonito, the fish is sometimes split into the back and the belly. Katsuobushi made from the back is called sebushi (背節), also known as obushi (雄節, “male”), and katsuobushi made from the belly is called harabushi (腹節), also known as mebushi (雌節, “female”). “Male” and “female” refer to the part of the fish, not the sex of the bonito. Harabushi is recognizable by the hollow where the internal organs used to be.
It is generally said that harabushi has slightly more fat and a richer taste, while sebushi is lighter. On the other hand, there is also a view that individual fish vary so much that the fat content cannot be said to differ in every case.
By Shaving Style: Thick, Thin, and Powdered
Under the labeling rules for shaved katsuobushi, flakes 0.2 mm or thinner are called usukezuri (thinly shaved), and flakes thicker than 0.2 mm are called atsukezuri (thickly shaved). The shaving style changes how the aroma and umami are released.
Thickly shaved
Its flavor takes time to dissolve, so it is extracted slowly. This makes a deep dashi with full umami and flavor.
Thinly shaved
Releases aroma and umami quickly, making dashi with a lively aroma and a clean taste. It can also be sprinkled over dishes as is.
Powdered
Because it is finely ground, it releases its flavor quickly. Besides being used for dashi, it can be added directly to dishes for extra flavor. Because the particles are so fine, some may remain even after straining, which can make the dashi cloudy or slightly gritty.
Katsuobushi in Japanese Homes Today
In the past, many households in Japan shaved hard blocks of katsuobushi at home with a tool called a katsuobushi kezuriki (katsuobushi shaver) to make dashi.
These days, it is common to buy katsuobushi already shaved at supermarkets and other stores. The four products you often see in Japanese supermarkets are hanakatsuo, small individual packs, dashi packs, and granulated dashi.
Hanakatsuo (花かつお)
Thinly shaved katsuobushi, named because the flakes spread out thin like flower petals (hana). Under the labeling rules, only flakes shaved from katsuobushi without mold (arabushi) can be labeled hanakatsuo. Besides being used for dashi, it is sprinkled directly on dishes such as okonomiyaki and hiyayakko (chilled tofu).
Small individual packs
Shaved katsuobushi packed in small portions, so you can use just the amount you need. The name on the package tells you whether it is made from arabushi or karebushi. Arabushi is labeled “かつお削りぶし” (katsuo kezuribushi), and karebushi is labeled “かつおかれぶし削りぶし” (katsuo karebushi kezuribushi).
Dashi packs
Dashi ingredients such as katsuobushi, kombu, and niboshi (dried sardines) packed in a bag. Just simmer it in a pot and take the bag out, and you have dashi with no straining needed. Rather than simmering it longer or squeezing the bag to make stronger dashi, we recommend first using it as directed on the package.
Granulated dashi
A seasoning that captures the flavor of dashi in granules. Just dissolve it in hot water or add it to dishes. Its convenience makes it widely used in everyday cooking. Its aroma and flavor go in a different direction from dashi made with katsuobushi.
Our Recommended Way to Make Bonito Dashi
This time, we used thinly shaved honkarebushi. You can make dashi the same way with hanakatsuo or small packs from the supermarket.
Ingredients
- Water: 17 fl oz (500 ml)
- Katsuobushi (thinly shaved): about 2% of the water's weight (about 0.35 oz / 10 g for 17 fl oz / 500 ml of water)
Instructions
| 1 | Bring the water to a boil, then turn off the heat. |
| 2 | Add the katsuobushi and leave it for about 2 minutes. |
| 3 | Gently strain out the katsuobushi. Do not squeeze it. |
About Water
In most parts of Japan, tap water is soft and well suited to making dashi. In hard water, minerals can make it harder for umami to dissolve. If your tap water is hard, using soft mineral water helps make dashi with a cleaner taste.
What Happens When You Change the Method
Using the same katsuobushi and water, we changed the conditions of our recommended method and made four other versions of dashi: steeping for 5 minutes, boiling for 3 minutes, squeezing firmly, and boiling for 3 minutes and then squeezing firmly.
Steep 5 Minutes
After turning off the heat and adding the katsuobushi, we left it for 5 minutes, longer than the recommended 2 minutes.
From our team
- The clear, elegant aroma remained
- Compared with our recommended dashi, the aroma was less vibrant and the umami less deep
- A light, gentle flavor
Boil 3 Minutes
We added the katsuobushi to boiling water and kept it on the heat for 3 minutes.
From our team
- The color was darker, but the aroma and flavor were not as strong as we expected
- We noticed slight harshness and off-flavors more than umami
Squeeze Firmly
We left it for 2 minutes, just like the recommended method, and squeezed the katsuobushi firmly when straining.
From our team
- The aroma was slightly stronger, with some heaviness
- Off-flavors and harshness came out, and it lacked the clarity of our recommended dashi
- Squeezing gives you more dashi, but it does not make it taste better
Boil and Squeeze
We boiled it for 3 minutes, then squeezed it firmly.
From our team
- The darkest color of all, and it looked cloudy
- Harshness and off-flavors, with a heavy, muddy overall impression
| Method | Aroma and Flavor |
|---|---|
| Recommended (steep 2 minutes) | Elegant, rich aroma. Clear taste with umami and depth |
| Steep 5 minutes | Clear but subtle aroma. Light, gentle taste |
| Boil 3 minutes | Dark color, but not much aroma. Harshness and off-flavors |
| Squeeze firmly | Slightly strong, heavy aroma. Off-flavors and harshness |
| Boil and squeeze | Darkest and cloudy. Heavy, with harshness and off-flavors |
None of the five dashi tasted fishy to us, but some methods brought out harshness and off-flavors. Also, a darker color does not necessarily mean a better aroma or more umami.
Katsuobushi has its own distinctive bonito aroma, but that does not necessarily mean it tastes fishy. To bring out the aroma and umami while keeping harshness and off-flavors down, it is important to make dashi at the right temperature and for the right amount of time.
However, these results are for thinly shaved katsuobushi. Some katsuobushi, such as thick shavings, is better suited to longer extraction, and the right method depends on the katsuobushi you use. In fact, even in Japan, the way dashi is made differs from home to home and region to region. Start with the method in this article and find the dashi you like best.
You can use this bonito dashi in dishes that make the most of its aroma, such as chawanmushi. We show how to make chawanmushi on our recipe page.
