Cloudy, Bitter Sumashi-jiru for Eighty Bowls
An 80-cover July banquet includes hamo no owan, a clear soup. The standard recipe for 5 L is 50 g ma-kombu and 80 g honbushi, seasoned with 30 mL usukuchi soy and 12 g salt. At the 13:00 prep the pot is behind schedule: the kombu goes into cold water and is brought to a hard boil, then held at a boil for five minutes before being removed. The katsuobushi is added to the boiling liquid and simmered for eight minutes. The dashi is strained through a fine mesh without skimming, seasoned, and tasted: it is cloudy, slightly bitter, coats the tongue, and the aroma is flat. The hamo has already been hone-nuki'd and yubiki'd and is waiting in iced water. Service is at 18:00, and the banquet manager refuses to change the menu.
1. Diagnose why the dashi is cloudy, bitter and coating the tongue, and give the corrected extraction schedule for 5 L.
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Diagnosis. Each fault maps to a specific mistake.
- Boiling the kombu extracts alginate and other polysaccharides from the frond. That is what produces the viscous, coating mouthfeel, the slight bitterness and part of the haze. Kombu should never be allowed to boil.
- Boiling the katsuobushi for eight minutes coagulates its proteins into fine suspended particles - the cloud - and prolonged heat extracts harsh, bitter notes while driving off the aroma compounds that make first dashi taste clean.
- Not skimming leaves the coagulated scum in the pot, where it is then broken up by straining through a fine mesh. Mesh catches flakes, not protein haze.
Corrected schedule for 5 L.
- 5 L soft water with 50 g ma-kombu. Either cold-soak 6–8 hours at ≤4°C, or heat gently to 60°C and hold 45–60 minutes.
- Remove the kombu at 60–65°C, before the water reaches a simmer.
- Bring to 80–85°C, add 80 g honbushi, and turn the heat off. Wait 1–2 minutes until the flakes settle.
- Skim the scum, then strain through a cloth-lined sieve. Do not press the flakes.
- Season last: 12 g salt and 30 mL usukuchi, then taste - roughly 0.8–1.0% salt in the finished broth.
Dashi is a temperature-controlled extraction, not a boil-up.
2. Can the seasoned soup be rescued? State the decision and the reasoning.
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No - remake it.
The faults are dissolved and suspended, not sitting on top. Alginate is in solution; coagulated protein is dispersed through the liquid. There is no skimming, straining or resting step that removes either, and dilution does not help: to dilute the coating mouthfeel to an acceptable level you would have to add so much water that the hamo-to-broth ratio, the salt and the soy all have to be rebuilt from scratch. At that point you have made a new soup, badly.
The schedule supports a remake. It is 13:00; a 60°C kombu extraction takes about an hour including heat-up, and the katsuobushi step takes five minutes. Start a second pot immediately in parallel with the rest of prep, and the 18:00 service is not at risk.
The hamo is the good news: it was hone-nuki'd and yubiki'd separately and is holding in iced water, so it is unaffected. Keep it. If any hamo had already been placed in the flawed soup, that portion is discarded - the coating cannot be washed off the fish without damaging its texture.
One more point for the record: the banquet manager is right that the menu does not change. Remaking the dashi is what allows the menu to stay as printed.
3. Plan the holding and service for 80 bowls from 16:00 to 18:30.
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Holding. Dashi is a low-acid, protein-bearing liquid and is not a shelf-stable product. Hold it either hot at ≥65°C or cold at ≤4°C, never in the lukewarm band. For this service the practical route is a bain-marie held at 80–85°C - hot enough to be safe, below a boil so the aroma does not cook off.
From 16:00.
- Strain the remade dashi, season in two batches rather than one, and taste each batch. Seasoning all 5 L at once means a single error cannot be corrected.
- Warm the bowls - a cold bowl drops the broth below serving temperature before it reaches the table.
- Hold the hamo in iced water until the last possible moment, then warm it in the broth at the pass, not in the held pot, so it does not overcook and break up.
Service.
- Taste at the top of service and again around bowl 40; a held broth concentrates by evaporation.
- Ladle a consistent volume, wipe the rim, and place the hamo and garnish so every bowl reads the same.
- Hold time hot should not exceed about two hours; anything left at 18:30 is discarded, not cooled and reused.
- Record holding temperatures at start and end of service.