How to Make Katsuo and Kombu Dashi

Name: How to Make Katsuo and Kombu Dashi
Total time: 50 min
Yield: Makes about 900 ml (5–6 bowls of miso soup)
Ingredients: Kombu (dried kelp) for dashi 10 g (about 1 piece, 10 cm square); Bonito flakes (hana katsuo) 20 g (about 2 light heaping double handfuls); Water 1L; Pot (holds 1.5 L or more) 1; Strainer, paper towels, bowl 1 each

Makes about 900 ml (5–6 bowls of miso soup) · About 50 min (30 min of this is just soaking the kombu in water)
The basic "awase dashi" (mixed stock) that is the base of Japanese flavor. Use it for miso soup, udon and simmered dishes.

① Soak the kombu in water→② Heat slowly and take out the kombu→③ Add the bonito flakes→④ Wait for them to sink→⑤ Strain

What to buy

Dry goods

Kombu (dried kelp) for dashiLook for "for dashi" on the label10 g (about 1 piece, 10 cm square)Bonito flakes (hana katsuo)Big, fluffy shaved flakes20 g (about 2 light heaping double handfuls)

Check what you already have

Water1LPot (holds 1.5 L or more)1Strainer, paper towels, bowl1 each

Tap an item to check it off (checks clear when you close the page).

How to make it

Soak the kombu in water

30 min or more

Lightly wipe the surface of the kombu with a well-wrung damp cloth or paper towel (just to remove dirt)
Put 1 L water and the kombu in a pot and let sit 30 minutes without turning on the heat

How to tell it's doneThe kombu has soaked up water and is a little bigger and soft.

Be carefulDon't wash the kombu with water. The white powder on the surface is flavor (umami), so don't scrub it off.

Heat slowly and take out the kombu

Medium-low heatAbout 10 min

Set the pot as it is over medium-low heat. No lid
When small bubbles start coming from the bottom and sides of the pot, take out the kombu with chopsticks

How to tell it's doneTake out the kombu when there are lots of small bubbles but it is not boiling hard yet.

Be carefulIf it boils with the kombu still in, it gets slimy and smells strongly of the sea. Take it out before it boils.

Bring to a boil and add the bonito flakes

Medium heat → Heat off1 min

Turn to medium heat and bring to a full boil
Add 20 g bonito flakes, spreading them over the whole surface
When it just comes back to a boil, turn off the heat right away. Don't stir

How to tell it's doneAll the bonito flakes are in the water, and the heat is off.

Wait for the bonito flakes to sink

Keep the heat offAbout 2 min

Let sit like this for about 2 minutes
If scum (whitish foam) floats up, gently skim it off with a ladle

How to tell it's doneThe bonito flakes have mostly sunk to the bottom of the pot, and the dashi on top is clear and golden.

Strain through a paper towel

About 2 min

Put a strainer over a bowl and line it with 1 paper towel
Gently pour the dashi from the pot through it to strain
For the bonito flakes left at the end, don't squeeze; wait for the liquid to drip through on its own

ReadyClear, golden dashi. Cool any you won't use right away, keep it in the fridge, and use it up in about 2 days.

Be carefulIf you squeeze the bonito flakes hard, the dashi gets cloudy and bitter.

📚 Learn more about this dish

🥬 Ingredient guide

Katsuobushi (bonito flakes)

🔪 Cutting & cooking tips

Aku (scum)Boiling Heat levels (high, medium, low)

If it didn't work out

The dashi is cloudyYou stirred after adding the bonito flakes, or squeezed while straining. Next time just leave it alone gently.

Slimy, or strong seaweed smellIt boiled with the kombu still in. Next time take it out as soon as small bubbles appear.

The flavor is weakThe kombu didn't soak long enough, or there weren't enough bonito flakes. Next time soak the kombu 1 hour or more and use a few more bonito flakes.

Bitter or harshIt cooked too long after adding the bonito flakes. Turn off the heat right after adding them.

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Made by YUU, a teen who loves cooking → About me