Japanese

Dashi Ichiban & Niban (Thermomix TM6)

The liquid foundation of Japanese cooking — konbu + katsuobushi, extracted in two passes. The TM6 holds 60 °C for konbu perfectly, where the stovetop can't. Zero-waste: one charge, two dashis, a season of umami.

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Base / Stock
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None
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Makes 1 L ichiban + 800 ml niban (from one ingredient charge)
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45 min (ichiban) + 20 min (niban) + optional 4–12 h cold soak

The Liquid That Makes Everything Else Make Sense

Pablo's name means this. Umami — the fifth taste, the savory depth, the thing that makes stock taste like stock and miso taste profound. And the purest expression of umami in any kitchen is dashi: two ingredients, ten minutes of actual work, and a broth so clean it changes how you think about flavor.

The secret is a single number: 7–8×. Glutamate from konbu (one of the most glutamate-rich foods on earth — 2,000–3,000 mg per 100 g dry) combines with inosinate from katsuobushi (dried, fermented, smoked bonito), and the perceived umami multiplies by seven to eight times what either ingredient delivers alone. This is umami synergy, and it's the most powerful flavor amplification in cooking. It's why dashi doesn't taste like kelp water or fish tea. It tastes like the background of every great Japanese meal.

Dashi on the stovetop is finicky. Konbu wants 60 °C — a narrow window where glutamate extracts maximally and the slimy alginate polysaccharides stay in the kelp. Above 65 °C the konbu goes bitter and gluey. Below 55 °C the extraction stalls. Nobody holds 60 °C on a home burner. The TM6 does it to the degree, for 30 minutes, without supervision. This is the cleanest example in the kitchen of the machine being objectively better than the alternative — not faster, not easier, better.

And then: zero-waste. The spent konbu and katsuobushi still hold flavor. A second extraction (niban, "second number") pulls everything else out — a deeper, earthier, less refined broth that is perfect for miso soup, braises, and cooking rice. One ingredient charge, two dashis, one full week of Japanese cooking in the fridge.

Ingredients

for Makes 1 L ichiban + 800 ml niban (from one ingredient charge)

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Everyday

For Ichiban (First Dashi, 1 L)

10 g konbu (dried kelp) — any Japanese grocery or Whole Foods Japanese shelf; one 10 × 10 cm square is ~10 g
20 g katsuobushi (bonito flakes) — ~2 loose handfuls; the standard thin-flake variety works
1 L filtered water — tap water works if it's not heavily chlorinated; filtered is safer

For Niban (Second Dashi, 800 ml)

Spent konbu + katsuobushi from the ichiban (do NOT discard)
800 ml fresh filtered water

Substitution Notes

No konbu or katsuobushi? Instant dashi (Ajinomoto Hondashi) in 1 tsp per 400 ml of hot water delivers 70% of the experience. Acceptable weeknight backstop; not the real thing.
Kombu-only (vegan) dashi? Skip the bonito entirely. Use 15 g konbu per 1 L water, cold-soak 8 h, heat to 60 °C / 30 min, strain. You lose the inosinate synergy (7–8× multiplier drops out) but you get a clean vegan umami base.
Tap water is heavily chlorinated? Chlorine interferes with glutamate extraction. Filter or let water sit uncovered 4 h to off-gas. Do not use softened water (sodium displaces extraction).

No Limits

Konbu — Single-Source

10 g Rausu konbu (Hokkaido, deeper and more assertive than Rishiri) — Whole Foods Brickell or Coral Gables Japanese shelf · online: Umami Mart, The Japanese Pantry, Marky's Caviar imports
Alternative: Rishiri konbu — cleaner, more refined; choose for delicate applications (chawanmushi, clear soups, ponzu base)
Storage: airtight, dark, cool — konbu keeps years dry. The white powder on the surface is mannitol, the flavor itself; never rinse it off.

Katsuobushi — Honkarebushi

20 g honkarebushi katsuobushi (fully fermented with Aspergillus glaucus, the most refined grade) — Yamaki, Marutomo, or Yamahigashi brands. Avoid arabushi (smoked-only, no fermentation) — cheaper but one-dimensional.
Thick-shaved (atsu-kezuri) for ichiban — deeper extraction, more body; thin-shaved (hana-kezuri) for niban + garnish — delicate perfume.
Source: Whole Foods Brickell, Umami Mart, Korin.com, Marky's

Water — Infrastructure

Filtered water (Pablo has ✓ — standard fridge filter is fine). For obsessive excellence: low-mineral spring water (Volvic) gives the cleanest extraction profile.
Never use softened water (sodium interferes).

Mise en Place

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Konbu wiped lightly with a damp cloth (NOT rinsed — the white mannitol powder IS the flavor)
Konbu scored with kitchen shears: 3–4 shallow cuts across the surface (opens the surface for extraction without breaking the structure)
Katsuobushi weighed and ready in a small bowl nearby
Filtered water measured (1 L for ichiban, 800 ml for niban)
Ice cube trays on a sheet pan, ready to receive strained dashi
Optional: if cold-soaking overnight, start the konbu + water in the TM6 bowl and refrigerate the whole bowl (or transfer to a container) up to 12 h ahead

Method

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Prep the Konbu

Wipe the konbu lightly with a damp cloth — just enough to remove visible debris.

Do NOT rinse the konbu under running water. The white powder on the surface is mannitol — the flavor itself. Rinsing washes away what you're paying for.

Score the konbu with kitchen shears: 3–4 shallow cuts across the surface (do not cut through — just open it up). This increases surface area for extraction.

Place scored konbu in the TM6 bowl with 1 L filtered water.

(Optional, recommended for 🔴 tier): Cover and refrigerate 4–12 h. Cold extraction pulls up to 2× the glutamate of hot extraction alone. Plan ahead once; reap the reward every time.

Konbu Hold at 60 °C (30 min)

Set: 60 °C / Sp 1 / 30 min . Measuring cup seated in place (this is a hold, not a reduction — no evaporation needed).

Walk away. The TM6 maintains 60 °C to within 1 °C for the full 30 minutes. This is the most important advantage of the TM6 for dashi — no stovetop can hold this window.

At T+30 min: lift the konbu out with tongs. Save it on a small plate or in a bowl nearby — it's going into the niban pass.

The water should be pale gold, slightly viscous, and smell clean and marine (not fishy or briny). If it smells briny: konbu got too hot; next batch drop to 58 °C.

Boil, Add Katsuobushi, Strain Ichiban

With the konbu removed: 100 °C / Sp 1 / 5 min. Bring the water to a full rolling boil.

At the boil: turn the TM6 OFF (full stop, not just 0 speed). Heat off; residual water temp ~95 °C.

Immediately add 20 g katsuobushi through the measuring cup hole. Replace the cup. Do not stir.

Let sit 30 sec –2 min maximum. The flakes will sink naturally. Do not agitate.

Set up a fine-mesh sieve lined with cheesecloth (or a clean, unscented tea towel) over a pitcher.

Pour the TM6 contents through the sieve. Do not press or squeeze the bonito. Pressing extracts bitter pyrazines (the same class of compounds that make burnt coffee bitter).

Transfer the spent katsuobushi + the reserved konbu back to the TM6 bowl — they're the start of the niban.

You now have ~1 L of clear, golden-amber ichiban. Taste: clean, savory, subtle smoke from the katsuobushi, no bitterness, no fishiness.

Niban — The Second Extraction

Return the reserved konbu + spent katsuobushi to the TM6 bowl.

Add 800 ml fresh filtered water.

Set: 100 °C / Sp 1 / 20 min . Cup seated.

At T+20 min: strain through cheesecloth again. You'll get ~700–800 ml of darker, earthier, slightly smokier broth.

Discard the solids now — they're spent. Compost if you're composting.

Niban is your workhorse dashi: use it for miso soup (it handles the miso without getting overwhelmed), for braising, for cooking rice, for any dish where dashi is part of a bigger flavor structure rather than the star.

Portion, Store, Label

Ichiban — clear-soup use: glass jar, fridge 3 days. Label with date + 'ichiban'.

Niban — workhorse use: separate glass jar, fridge 3 days. Label with date + 'niban'.

Freezer cubes (recommended): Pour into silicone ice cube trays (20–25 ml per well). Freeze. Transfer to labeled zip bags. Keeps 3 months. One cube = one seasoning shot for a braise, a pan sauce, or a rice cook.

Never store dashi in plastic for more than 24 h — it picks up plastic flavor faster than almost any other stock because the flavor itself is so subtle.

Timeline

T-12:00 — (Optional) Cold soak Konbu + 1 L water in TM6 bowl. Refrigerate overnight (4–12 h). Up to 2× glutamate yield vs hot extraction alone.
T+0:00 — Start the konbu hold If not cold-soaked: konbu + 1 L water into TM6 bowl. Set 60 °C / Sp 1 / 30 min. Measuring cup seated (this is a hold, not a reduction).
T+30:00 — Remove konbu Lift konbu out with tongs. Save it for the niban pass. Do NOT let it boil — boiled konbu releases bitter alginate polysaccharides.
T+30:30 — Boil Without konbu: 100 °C / Sp 1 / 5 min. Bring water to a full rolling boil.
T+35:30 — Add katsuobushi Turn TM6 OFF (not just stop — OFF). Add 20 g katsuobushi through the measuring cup hole. Let the bonito sink naturally (60–90 sec).
T+37:00 — Strain ichiban Set up sieve lined with cheesecloth over pitcher. Pour TM6 contents through. Do NOT press or squeeze the bonito — pressing extracts bitter pyrazines.
T+40:00 — Reserve ichiban 1 L clear, golden-amber dashi. Taste: clean umami, subtle smoke, no bitterness. Into fridge (3 days) or ice cube trays (3 months).
T+40:00 — Start niban Return spent konbu + katsuobushi to the TM6 bowl. Add 800 ml fresh water. 100 °C / Sp 1 / 20 min. Cup seated.
T+60:00 — Strain niban Through cheesecloth again. Darker, earthier, slightly smokier than ichiban. Discard solids now — they're spent.
T+65:00 — Portion + store Ichiban → labeled jar or cube tray (for clear soups, chawanmushi, ponzu). Niban → separate jar (for miso soup, braises, rice water). Label: date + which dashi.