Yuba (soy milk skin)

A film lifted from hot soy milk

Yuba is the thin skin that forms on the surface of soy milk as it is held warm. The film is mostly protein and fat, and it is lifted off by hand or with a skewer, one sheet at a time, as each one sets. Fresh sheets are eaten soft, often in a simmered dish or as sashimi-style slices in Minobu. They can also be dried and rehydrated later. Shurtleff and Aoyagi's account of the film says that the earliest Chinese reference is a record of 1695, and the word yuba is recorded in 1813, so the name is later than the thing.

The sources hold two traditions apart. Kyo-yuba from Kyoto is made in a pot fitted with a square wooden frame, warmed over a hot-water bath or on low heat, and its films are lifted by hand or skewer. Minobu yuba in Yamanashi is made in a flat pan with a stick. Each is a documented preparation, and neither is merged with the other here.

The Kyoto method

The Kyoto method starts from soy milk made by soaking, grinding and simmering the beans over low heat, then separating the milk from the okara. The milk is poured into the framed pot and warmed over the hot-water bath, the yusen, or over low heat. As the surface heats, a thin film forms. It is lifted off by hand or with a skewer, and that first sheet is fresh yuba, or hikiage yuba. The later sheets are the same product, lifted as they form.

For dried yuba the fresh sheets are dried, and the dried form is rehydrated before use. The sources give no drying time or temperature for the Kyoto method.

A laboratory bath method

A 2026 study in Foods used soy milk at 7.0% solids and pH 7.5, boiled for three minutes, and poured into a stainless steel pot whose base sat in a water bath held at 85°C. A film was collected every 20 minutes until no further film formed, and the films were dried at 60°C for six hours. The study is a controlled laboratory report, and its milk temperature was not reported, so it is not a home schedule.

A film every twenty minutes puts the yield in the study's hands, not the cook's. Shurtleff and Aoyagi cite a 1921 record of fifteen to twenty films from one batch. The sources give no sheets-per-litre figure for a home pan.

Home routes not yet recorded

A hotplate or electric skillet route appears in a Japanese cooking publication that a dossier describes, but that publication was not identified, so its heat settings and pan are not sourced and the route is not given here as a method. Using an appliance for the hold is an untested adaptation, and the Kyoto pan over a controlled hot-water bath is the documented route to follow.

Open questions

The home milk temperature and the bath setting that reaches it are not given. The pan size, the sheets per litre and the evaporation rate are not reported. No storage time is given for fresh yuba, and the dried form's storage is not stated beyond rehydration before use.