Choose your method
- Ichiban dashi: 10g kombu + 20g katsuobushi per 1L — delicate, for miso soup and clear broth
- Niban dashi: spent kombu + katsuobushi simmered 10 min — robust, for nimono and braises
- Kombu-only (vegan): 10g kombu per 1L, 60°C for 20 min — gentle umami, plant-based
- Cold-brew: kombu + cold water overnight in fridge — zero cooking, cleanest flavor
- Shiitake dashi: 3–4 dried shiitake per 1L, cold steep 8h — deep, earthy, vegan
- Instant: ½ tsp Hondashi per 200ml — quick, good enough for heavily seasoned dishes
Core Ratios at a Glance
| Type | Ingredients per 1L water | Time | Best for |
|---|---|---|---|
| Ichiban | 10g kombu + 20g katsuobushi | 25 min | Miso soup, clear soup, noodle dip |
| Niban | Spent kombu + katsuobushi | 10 min simmer | Nimono, braised dishes, hearty miso |
| Kombu-only | 10g kombu | 20 min at 60°C | Vegan miso, vegetable nimono |
| Shiitake | 3–4 dried shiitake | 8h cold soak | Vegan ramen base, mushroom risotto |
| Cold-brew | 10g kombu | 8–12h in fridge | Delicate dipping sauces, suimono |
| Instant | ½ tsp dashi powder | 30 sec | Weeknight miso, curry udon, quick braise |
How to Make Ichiban Dashi (First Extract)
Ichiban dashi is the foundation of Japanese cooking. The method is an infusion — low heat, precise timing, and no boiling. Total time: 25 minutes.
- Place 10g kombu (a piece roughly 10 × 10cm) in a pot with 1L cold filtered water. Let it sit for 30 minutes if you have time — this cold soak starts the glutamic acid extraction.
- Heat the pot slowly over medium-low heat. Target 60°C — small bubbles will form on the bottom of the pot but the water should not simmer. If you have a thermometer, use it the first time.
- Hold at 60°C for 20 minutes. The kombu should look plump and soft. If the water starts to boil, immediately reduce heat — boiling kombu releases bitter compounds.
- Remove the kombu with tongs. Set it aside for niban dashi or kombu reuse recipes.
- Bring the kombu stock to just below a boil (about 85°C), then remove from heat. Add 20g katsuobushi (loosely packed bonito flakes). Do not stir — let the flakes sink naturally.
- Steep for 2–3 minutes. Strain through a fine-mesh sieve lined with cheesecloth or a paper towel. Do not press or squeeze the katsuobushi — pressing extracts bitterness and cloudiness.
Result: pale gold, clear, with a clean umami flavor and subtle smokiness. This is the dashi for miso soup, clear soups (suimono), dipping sauces (mentsuyu base), and delicate chawanmushi.
How to Make Niban Dashi (Second Extract)
Niban dashi reuses the spent kombu and katsuobushi from ichiban dashi — a no-waste approach that yields a darker, more robust stock.
Place the reserved kombu and katsuobushi in a pot with 1L fresh cold water. Bring to a gentle simmer (not a rolling boil) and cook for 10 minutes. Optionally add 5g fresh katsuobushi in the last minute for extra depth. Strain through a fine-mesh sieve.
Result: darker than ichiban, with a stronger, less refined flavor. Use for nimono (simmered dishes), braised vegetables, oden, and miso soup when you want a hearty stock rather than a delicate one. Niban dashi is also the base for many home-style Japanese soups where other strong flavors (miso, soy sauce) dominate.
For what to do with the spent kombu and katsuobushi after niban dashi → Dashi reuse guide
Kombu-Only Dashi (Vegan Method)
Kombu-only dashi produces a gentler, purely vegetarian umami. The method is identical to the first four steps of ichiban dashi — without the katsuobushi.
Hot method: soak 10g kombu in 1L cold water for 30 minutes, then heat slowly to 60°C and hold for 20 minutes. Remove kombu. The stock is ready.
Cold-brew method (preferred): place 10g kombu in 1L cold water in a glass jar or container. Refrigerate for 8–12 hours. Remove the kombu in the morning. No heat required. This produces the cleanest, most delicate dashi — professional kaiseki kitchens often use this method for their most refined dishes.
Uses: vegan miso soup, vegetable nimono, shojin ryori (Buddhist temple cuisine), and as the liquid base for ramen broth when building a vegan tare.
Storage: cold-brew kombu dashi keeps 3–4 days refrigerated. It freezes well for up to 1 month.
Cold-Brew Dashi: The Zero-Cooking Method
The simplest dashi method. Place 10g kombu in 1L cold water in a jar. Refrigerate overnight (8–12 hours). Remove the kombu. Done. No stovetop, no thermometer, no timing.
Cold-brew extracts glutamic acid slowly and gently — no risk of bitterness from overheating. For a full ichiban-quality dashi from a cold-brew base: heat the strained liquid to 85°C, add 20g katsuobushi, steep 2 minutes, and strain. Shelf life: 3–4 days refrigerated.
How to Use Instant Dashi Powder
Instant dashi (Hondashi by Ajinomoto is the most widely available brand) dissolves in hot water for an immediate stock. The ratio: ½ teaspoon dashi powder per 200ml hot water. Stir until dissolved.
Instant dashi contains MSG, salt, sugar, and dried bonito extract. It is saltier and less nuanced than scratch dashi. Reduce soy sauce and other salt in your recipe by about 25% when using instant dashi to avoid over-seasoning.
When to use instant: weeknight miso soup, udon broth, quick nimono, and any dish where dashi is one seasoning among several. It is not worth the convenience tradeoff for clear soups or dipping sauces where dashi flavor is exposed.
Brands: Ajinomoto Hondashi (most common, available at most Asian groceries and Amazon), Marutomo (slightly more refined), Shimaya (has a kombu-only version for milder flavor). Kayanoya makes a premium dashi pack (teabag-style) that sits between instant and scratch in both convenience and quality.
Shop Hondashi instant dashi on Amazon →
Troubleshooting: Fixing Common Dashi Problems
- Dashi tastes bitter: the kombu was boiled. Kombu must never exceed 70°C. Next time, remove it when small bubbles form on the pot bottom (60–65°C). If you already have bitter dashi, add a pinch of sugar and a splash of mirin to mask the bitterness.
- Dashi is cloudy: the katsuobushi was squeezed through the strainer. Let it drip naturally — pressing forces fine particles through. Cloudy dashi tastes fine but lacks the clarity needed for suimono.
- No umami flavor: hard tap water inhibits glutamic acid extraction. Switch to filtered water. Also check your kombu — old kombu loses potency. Fresh Hokkaido kombu makes a noticeable difference.
- Too fishy: reduce katsuobushi to 15g per liter, or steep for only 1–2 minutes instead of 3. Thicker katsuobushi shavings (atsukezuri) release flavor more slowly and produce a less fishy result than standard thin shavings (hanakatsuo).
- Dashi spoiled quickly: cool dashi rapidly (ice bath to below 40°C within 30 minutes) before refrigerating. Slow cooling promotes bacterial growth.
How to Store Dashi
Fridge: airtight container, 3–4 days. Discard if it smells sour. Freezer: ice cube trays (30ml each), transfer to a freezer bag. Keeps 1 month. Drop frozen cubes directly into soups — no thawing needed.
Frequently asked questions
What is the difference between ichiban and niban dashi?
Ichiban dashi (first extract) is a quick, delicate infusion — kombu steeped at 60°C and katsuobushi steeped for only 2–3 minutes. It produces a pale gold, clean-flavored stock used for miso soup, clear soups, and dipping sauces. Niban dashi (second extract) reuses the spent kombu and katsuobushi by simmering them for 10 minutes in fresh water. It is darker, more robust, and slightly less refined — best for braised dishes, hearty miso, and nimono where the stock is one flavor among many.
Can I use dashi powder instead of making it from scratch?
Yes. Instant dashi powder (Hondashi is the most common brand) dissolves in hot water at a ratio of ½ teaspoon per 200ml. It produces a serviceable stock in seconds. The tradeoff: instant dashi contains MSG, salt, and sugar, so reduce soy sauce and other salt in your recipe. Scratch dashi has a cleaner, more nuanced flavor — worth the effort for clear soups and dipping sauces where the stock is the star. For heavily seasoned dishes like curry udon or nimono, instant dashi is a reasonable shortcut.
Why does my dashi taste bitter?
Bitterness comes from boiling the kombu. Kombu releases bitter compounds (mannit and alginic acid byproducts) at temperatures above 70°C. The solution: heat the water slowly to 60°C, hold it there for 20 minutes, and remove the kombu before the water reaches a boil. If using a thermometer is impractical, remove the kombu when small bubbles begin forming on the bottom of the pot — that is roughly 60–65°C.
Can I make dashi without kombu?
You can make katsuobushi-only dashi (katsuo dashi): bring 1L water to a boil, remove from heat, add 30g katsuobushi, steep 3 minutes, and strain. The result is smoky and strongly fish-flavored — excellent for assertive miso soup or mentsuyu. You lose the glutamic acid (umami) that kombu provides, so the flavor is more one-dimensional. Adding a pinch of MSG compensates for the missing kombu umami if you are comfortable with that.
How long does homemade dashi keep?
Fresh dashi keeps 3–4 days in the refrigerator in an airtight container. It freezes well for up to 1 month — pour into ice cube trays or small containers for easy portioning. Frozen dashi cubes can go directly into soups and simmering dishes without thawing. If refrigerated dashi develops a sour smell or cloudiness, discard it.
What is the difference between dashi and stock?
Western stock is made by simmering bones, meat, and vegetables for hours (typically 4–8 hours for chicken stock, 12–24 for beef). Dashi is an infusion — kombu steeps at 60°C and katsuobushi steeps for 2–3 minutes. The total active time is under 30 minutes. Dashi is lighter, cleaner, and built around umami (glutamic acid from kombu + inosinic acid from katsuobushi) rather than collagen richness. They are not interchangeable — dashi lacks the body of stock, and stock lacks the clarity of dashi.
Can I freeze dashi?
Yes. Freeze dashi in ice cube trays (each cube is roughly 30ml), then transfer to a freezer bag. Keeps for 1 month. Drop frozen cubes directly into miso soup, noodle broth, or simmering dishes. For larger portions, freeze in 500ml containers. Label with the type (ichiban, niban, kombu-only) and date. Thaw overnight in the fridge for cold applications like dipping sauces.
Is dashi gluten-free?
Dashi made from kombu and katsuobushi is naturally gluten-free — neither ingredient contains wheat. However, some instant dashi powders include wheat-derived ingredients or soy sauce solids. Check the label if gluten is a concern. Brands like Shimaya and Kayanoya offer gluten-free instant dashi. Homemade dashi from whole ingredients is always the safest option for gluten avoidance.
What is the best kombu to use for dashi?
Rishiri kombu produces the clearest, most refined dashi — prized for clear soups (suimono) and high-end Japanese cooking. Ma-kombu from southern Hokkaido gives a richer, slightly sweeter stock — excellent for miso soup. Hidaka kombu is thinner and softens quickly, making it the best dual-purpose choice if you plan to eat the kombu after making dashi. For everyday cooking, any Hokkaido-harvested kombu labeled for dashi (だし用) will work well.
Can I make dashi in a rice cooker?
Yes, using the keep-warm function. Add 10g kombu and 1L cold water to the rice cooker, close the lid, and set to keep-warm (not cook). After 1 hour, remove the kombu, add 20g katsuobushi, let steep 3 minutes, and strain. The keep-warm setting on most rice cookers holds water at 60–70°C — close to ideal dashi extraction temperature. This hands-off method is convenient but slower than stovetop.
Where to go next
- What Is Dashi? — what dashi is, umami science, and type overview
- How to Use Kombu — kombu technique, cold-brew ratios, and grade guide
- What Is Kombu? — kombu varieties, grades, and harvesting regions
- How to Use Katsuobushi — katsuobushi types and how to handle them
- What Is Katsuobushi? — production process and grade differences
- Dashi Reuse — what to do with spent kombu and katsuobushi
- Miso Ramen — dashi as part of the ramen broth base
- Hondashi vs Scratch Dashi — side-by-side comparison with substitution ratios and a hybrid method
- Guides Hub — all ingredient and technique guides