Dashi is the fastest real stock there is, and it is ruined by boiling. Kombu simmered hard goes bitter and slimy; bonito boiled goes sour and fishy. Both want water held below a simmer, which means you're steeping rather than cooking.
The ratio1 quart water + 1 piece kombu (steep 20 min, pull at 140°F) + 1 cup bonito (steep 5 min off heat).
By Vince Gonzalez · Published July 2026 · Sourcing verified 5 Jul 2026
Prep5 min
Cook15 min
Makes1 quart
CuisineJapanese
Cost$
Gluten-freeDairy-free
Contains fish
The Ingredients — and where to get them
Cook for1quart
Kombu
A postcard-sized piece of dried kelp. Wipe it, don't wash it — the white powder on the surface is savour, not dirt.
Soft water if you have it. That's genuinely the whole ingredient list.
1 quart
Local / market
The Rundown
Greedometer●●●●●Squeaky clean
About as virtuous as dinner gets. · plan ahead — needs marinating, soaking, or resting time
EffortSome doing
Cook it with
Instant PotSlow cookerOne-pot
The Method
Steep the kombu coldKombu in cold water, ideally thirty minutes ahead, or overnight in the fridge for the cleanest result.
Heat slowly and pull it earlyBring it toward a simmer over low heat and remove the kombu just as small bubbles appear at the edges, around 140°F. If it boils with the kombu in, you'll taste it.
Add the bonito off the heatBring the water to just under a boil, kill the heat, and drop the flakes in. They'll sink as they hydrate.
Steep five minutes, then strainThrough a fine sieve lined with a paper towel. Don't press the flakes — squeezing them makes it cloudy and bitter.
Make it yoursDried shiitake instead of bonito makes a vegan dashi with real depth. The spent kombu and flakes make a second, weaker batch that's perfect for miso soup. Miso whisked into the finished dashi is dinner in four minutes.
Can you make How to Make Dashi in an air fryer? — Yes, with an insert
Not on its own — an air fryer can’t hold a pool of liquid. You can simmer it in an oven-safe dish or a silicone insert made to fit the basket, but the broth won’t reduce or brown the way it does on the stove, and that insert comes out scorching, so use oven mitts. For real depth, a pot on the stove wins.
Can you freeze How to Make Dashi? — Yes
Yes — it freezes well. Cool it fully, portion into airtight containers, and it keeps a few months; thaw in the fridge and reheat gently.
Can you make How to Make Dashi ahead of time? — Yes
Yes — it holds well and often tastes better the next day. Make it ahead and reheat gently before serving.
Is How to Make Dashi gluten-free? — Yes
Yes — nothing in this recipe as written contains gluten. As always, glance at the labels on any packaged items (broth, sauces, chocolate), since brands vary.
Is How to Make Dashi vegan? — No
No — it contains seafood, so it isn’t vegetarian or vegan.
Community Notes
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