Vol. XXVI · Doughs of the World Plate 3 of 10steamed buns, 馒头, 包子, 花卷, 叉烧包, mantou, baozi, steaming, yeast dough, 老面, 碱, low-protein flour, wrinkling, collapse, 发面TM

Steamed Buns.

Lift the lid the moment the steaming stops and the buns wrinkle like old apples. Leave it five minutes and they stay smooth.

Steamed buns are bread without a crust. A dough of 中筋 or low-protein flour (XXIV.1), about 45–50 % water (often milk), a little sugar and 1 % yeast is kneaded very smooth — any roughness shows on a crustless surface — rested, shaped, proofed and steamed over boiling water, usually 12–18 minutes. Because steam holds the surface at 100 °C and wet, no Maillard browning occurs (VIII.2) and no crust sets: the bun stays white and expands evenly. Traditional northern 馒头 are raised with 老面, a sourdough (XXIV.7), with a little 碱 (alkali) kneaded in to neutralise its acid; too little leaves them sour, too much yellow and soapy (V.7).

Two faults are common. Over-proofed or under-kneaded buns collapse and wrinkle. And buns uncovered as soon as the heat goes off meet cold air while still full of hot, expanded gas: the gas contracts, the surface puckers. So the steamer is turned off and left closed for 3–5 minutes before opening, letting the pressure and temperature fall slowly. The time to steam grows with the bun's size, by the square law (II.2). 包子 add a filling and a pleated top; 叉烧包 use a dough with baking powder for its split, "smiling" top. The workshop proofs and steams.

Below: the volume of a shaped bun during its final proof at the temperature you choose (course fermentation model, 1 % yeast), with the ready range, and the steaming time for the bun's size by the square law (teaching calibration: 15 minutes for a 70 mm bun).

What you will learn

Make smooth 馒头 and 包子 dough.
Proof and steam buns.
Prevent wrinkling and collapse.
Use 老面 and 碱.

Workshop

Proof: course fermentation model with 1 % instant yeast from the shaped bun (1.0), ready range 1.5–2 times (teaching). Steaming time: 15 minutes × (diameter ÷ 70 mm)², the square law of II.2 calibrated to common practice for a 70 mm bun.

Smooth dough, warm proof, a closed rest

In the course model, shaped buns at 32 °C reach the ready range after about 46 minutes, at 26 °C after about 56. By the square law a 50 mm bun steams in about 8 minutes and a 100 mm one in about 31. Steamers put buns over vigorously boiling water from the start (or start cold, which gives a final proof as the water heats — a common home method), and the lid stays on.

Method for 馒头 (8 buns): mix 500 g 中筋 flour, 250 g warm milk or water, 5 g instant yeast and 20 g sugar; knead 10 minutes until very smooth; rest until doubled (XXIV.6); knead again firmly to expel all gas — the smoother now, the smoother the buns; roll into a log, cut into pieces or shape rounds tucked underneath; proof on squares of paper in a warm steamer until about 1.5 times; steam over high heat 15 minutes; turn off the heat and wait 3–5 minutes; then open. For 包子, roll circles thinner at the edges, fill, pleat, proof and steam the same way. Leftover buns are re-steamed (XXIV.11) or sliced and fried (炸馒头片).

At the stove

Steam two batches of buns: open one steamer the moment the heat goes off and leave the other closed five minutes. Compare their surfaces.

The 馒头 is traditionally credited to 诸葛亮 in the Three Kingdoms period, who is said to have offered bread shaped like heads (蛮头) to a river spirit instead of human sacrifices; the story is legend, but steamed wheat buns are indeed ancient in northern China.

Terms

馒头 / 包子: Plain steamed bun / filled steamed bun.
老面: A sourdough kept for steamed bread (XXIV.7).
碱: Alkali kneaded into 老面 dough to neutralise its acid.
Wrinkling: Puckering of buns cooled too fast after steaming.

Steamed buns are crustless bread: soft flour, very smooth dough, a warm proof to about 1.5×, steaming time by size squared, and 3–5 minutes closed after the heat goes off so they do not wrinkle.

Sources

A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.
H. McGee, On Food and Cooking: The Science and Lore of the Kitchen, 2nd ed., Scribner, 2004.