Yeast dumplings and steamed buns

Why

Czech fruit yeast dumplings, steamed buns, Germknödel and Chinese bao keep rising during the first minutes of cooking, because heat expands the gas from fermentation, and only then does the dough set as proteins coagulate and starch gelatinises. If the lid is lifted before the dough has set, or the hot buns are taken straight out into cold air after the heat goes off, the sudden cooling contracts the gas and steam inside and the still-soft surface wrinkles or collapses; that is why bao are left under the lid for a few minutes after switching off. A rolling boil knocks dumplings about and tears them, and large pieces or a cold filling, such as fruit straight from the fridge, lengthen the cooking, so the centre easily stays raw and gummy. Dough sticks to the steamer or the pan bottom when it sits directly on metal or the pieces touch, because they still expand in the steam; over-proved dough, on the other hand, spreads into a flat disc and comes out wrinkled.

How to do it

• Let shaped dumplings and buns prove briefly under a tea towel until visibly puffier, then cook them straight away.
• Add fruit dumplings to gently simmering water in batches so they don't touch, and turn them carefully halfway through.
• Steam with the lid on and don't open it during cooking; put a small square of baking paper under each piece.
• Leave bao and steamed buns under the lid for about 5 minutes after turning off the heat; take a Czech bread dumpling out at once and prick it (see the Czech bread dumplings card).
• Check doneness by cutting one open or with a skewer: the dough around the centre must not be sticky.

If it goes wrong

Finish a raw centre: return the dumpling to the water or steam for a few minutes, bao to the steamer. Collapsed or wrinkled buns can't be made fluffy again but taste just as good; next time don't let the dough over-prove and lift the lid only after a while. Free a stuck piece with a damp spatula, or serve it on its paper.