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Shallow pan over controlled hot water (yuba pan)

yuba pan · yusen pan

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A wide shallow pan of soy milk standing in a controlled hot-water bath, so that the bath heats evenly while the open surface forms film after film of yuba.

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Illustration of Shallow pan over controlled hot water (yuba pan).

Overview

A wide shallow pan of soy milk stands in a controlled hot-water bath. The bath heats evenly while the open surface forms film after film of yuba.

This is a documented arrangement. MAFF's Kyoto yuba page describes soy milk poured into a pot fitted with a square wooden frame and warmed over a hot-water bath (yusen) or low heat, with each film lifted by hand or skewer. Li and colleagues (2026) stood a stainless-steel pot of 7% solids soy milk, boiled for 3 minutes first, with its base fully immersed in an 85 °C bath, and lifted a film every 20 minutes until none formed. Chen's group also used an 85 °C bath. A home version built from a circulator and a household pan is untested.

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How it works

Yuba is a protein-lipid film that assembles at the soy milk and air interface. Heated proteins denature and bond, oil bodies are trapped, and evaporation densifies the film.

Each sheet is as large as the exposed surface, so width matters and depth does not. The bath caps the heat reaching the pan base at the bath temperature, while the open surface loses water.

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Documented uses

Yuba: the pan's film is lifted as each sheet forms. The laboratory study gives the process; the Kyoto entry gives the traditional frame and bath.

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Measuring

Measure the milk temperature just below the surface, the time between sheets, the number of sheets, and the milk volume and solids (Li used 7%).

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Limits

The laboratory reports give the bath setpoint, not the milk temperature. The milk level falls by evaporation and as films are lifted. Sheets per litre are unreported.

No storage data exists for fresh home yuba.

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History

Kyoto yuba is a traditional method described in MAFF's food-heritage entry. The 2026 laboratory study used a stainless-steel pot in an 85 °C bath. The home circulator version is untested.

Site

SettingA kitchen: a wide, shallow pan of soy milk standing in a larger vessel of water held at a controlled temperature.
ClimateA controlled hot-water bath at about 85 °C (185 °F) in the laboratory report; the open surface loses water into the room air.
NotesThe laboratory report gives the bath setpoint, not the milk temperature. No source gives the pan's dimensions for a home set-up.

A build is made where it stands: moving it means building it again.

How it is built

Materials

  • 1 Wide, shallow stainless pan — Uncovered, with its base fully immersed in the water bath. Kyoto uses a pot fitted with a square wooden frame; Li's study used a stainless-steel pot.
  • 1 Water bath vessel — A larger vessel of water held at a controlled temperature. At home, a sous-vide circulator in a larger pot is proposed; no source shows it.
  • 1 Skewer or stick — Lifts each film.
  • 1 Food probe thermometer — In the milk just below the surface.
  • Soy milk — Boiled for 3 minutes first in the laboratory study, at 7% solids.
  1. Boil the soy milk for 3 minutes first, in the laboratory study.
  2. Pour the soy milk into the wide, shallow pan, and set the pan with its base fully immersed in the bath at 85 °C.
  3. Leave the pan uncovered. A lid or a sealed bag defeats the process.
  4. Lift a film every 20 minutes, with a skewer or stick, until no more form.
  5. Probe the milk just below the surface and note the time between sheets.

Places

Kyoto

Traditional preparation · Region evidence

The Kyoto yuba entry describes soy milk poured into a pot with a square wooden frame over a hot-water bath (yusen) or low heat.

More equipment from KyotoLocation source 1 →

Related

Used for

  • Yuba (soy milk skin)

    The protein-lipid film that forms on hot soy milk, lifted sheet by sheet from a wide shallow pan; eaten fresh, or dried for later use.

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