Dashi (Kombu and Katsuobushi to Water)

20g per litre

Kombu (dried kelp) — Cold-steep in water before heating; remove before boiling to avoid bitterness and sliminess

30g per litre

Katsuobushi (bonito flakes) — Added after kombu is removed; steep off-heat 3–5 minutes then strain without pressing

1 litre

Water — Soft water or filtered water produces cleaner flavour; avoid hard, chlorinated water

Wipe kombu with a damp cloth (do not rinse off the white mannitol bloom). Combine kombu and cold water; steep 30 minutes or overnight in the refrigerator. Heat slowly to 60–65 °C over 10–15 minutes — the ideal glutamate-extraction window. Remove kombu just before the water reaches a full simmer (approximately 80 °C). Bring to 85 °C, add katsuobushi, turn off heat, steep 3–5 minutes, then pass through a fine-mesh strainer or cheesecloth without pressing. The resulting stock should be clear, golden-amber, and intensely savoury. Use within 3 days refrigerated or freeze up to 1 month.

• Never let dashi boil with kombu present — boiling releases alginic acid, producing a slimy, bitter result.
• Squeeze or agitate the katsuobushi as little as possible during straining; pressing releases bitter compounds and cloudiness.
• Cold-steeping kombu overnight (up to 24 hours in the refrigerator) maximises glutamate extraction while preventing bitterness — ideal when time allows.
• The white powder on dried kombu is mannitol and is flavour-active; do not wash it off, only wipe dust with a dry or barely damp cloth.
• Ichiban dashi should be used the same day for clear soups; its flavour diminishes quickly, while niban dashi is more forgiving.

• Niban dashi (second pull)

  Re-steep the spent kombu and katsuobushi in fresh water at a gentler simmer for 10–15 minutes; yields a rougher, more assertive stock suited for miso soup and simmered (nimono) dishes rather than delicate sauces

• Kombu dashi (vegan)

  Kombu only, 20g per litre; cold-steep overnight for maximum glutamate extraction with no animal product; the base for shojin ryori temple cuisine

• Niboshi dashi

  Replace katsuobushi with 20–30g dried sardines (niboshi); remove heads and entrails to reduce bitterness; more assertive, used in robust miso soups and ramen

• Shiro dashi concentrate

  Highly reduced ichiban dashi combined with light soy (usukuchi) and mirin in roughly 4:1:1 ratio; dilute 1:7 with water before use

• Awase dashi from high-grade ingredients

  Hon-karebushi (fully fermented bonito) at 40g per litre and rishiri kombu produces premium dashi for kaiseki clear soups (osuimono)

• Mentsuyu (tsuyu) concentrate ratio

  Ichiban dashi is the base for tsuyu; a standard 3:1:1 dashi-to-soy-to-mirin dilution forms the concentrate

• Ramen tare to broth ratio

  Dashi can replace or extend pork/chicken ramen broth, especially in Tokyo shoyu styles

• Miso soup base ratio

  Standard miso soup uses approximately 10–15g white miso per 200 ml dashi

1. 1.Japanese Farm Food — Nancy Singleton Hachisu
2. 2.The Japanese Kitchen — Hiroko Shimbo
3. 3.Dashi and Umami: The Heart of Japanese Cuisine — Cross Media Ltd / Umami Information Center
4. 4.Washoku: Recipes from the Japanese Home Kitchen — Elizabeth Andoh

Confidence: high