Dashi
出汁 · kombu and katsuobushi stock

Water L

2 L	water — soft water is best
20 g	kombu — 1% of the water
40 g	katsuobushi — 2% of the water

Video says 20 g kombu for ~2 L and “a big handful” of bonito; Kansai uses more kombu, Kanto more bonito.video 9-2

Ichiban dashi

1. Rinse the kombu quickly. Start in cold water. (Restaurants: in the fridge the night before.)video 9-2
2. Heat to 65–70 °C and hold; kombu gives up most flavour there. Up to 30 min for thick kombu. Never boil. Lift the kombu out before the boil.video 9-2
3. Alternative: at 80 °C (bubbles on the bottom) remove the kombu.
4. Raise to 90 °C, add all the katsuobushi at once, go to ~95 °C, switch off.video 9-2 Steep 3 min — the video says ~10 min, until the flakes sink.video 9-2
5. Strain through paper in a zaru. Do not squeeze — bitterness (egumi).video 9-2

Niban dashi

1. Used kombu + used bonito in cold water, about half the first amount of water.video 9-2
2. Medium heat to just before the boil; lift the kombu out alone (sliminess). Then low heat, gentle simmer 5 min. Optionally a second charge of fresh bonito (oigatsuo). Strain, no squeezing.video 9-2

Kombu types (tasting notes)

Type	School	Tasted
Ma	rich, elegant; Osaka; udon, takoyaki. Glutamate-rich.	smokier, stronger
Hidaka	mild, cheapest, used in Tokyo	fishier, all over the place
Rishiri	clean, refined; Kyoto	rounder, best
Rausu	strongest, richest; not for clear soup; expensive; ramen. Glutamate-rich.	herbaceous, stronger

• Oboro kombu: 70–80 °C.
• Spent kombu: freeze, or shred for tsukudani.video 9-2
• Umami: glutamic acid (kombu), inosinic acid (bonito), guanylic acid (dried shiitake).