Puff pastry and laminated dough

Why

Laminated dough is a sheet of dough wrapped round a sheet of butter, rolled out and folded again and again: each letter fold triples the number of layers, so in the end they are paper-thin. In a hot oven the water in the dough and in the butter, which has at least 80 % fat and up to 16 % water, turns to steam; the fat layer traps it between the sheets of dough and lifts them before the dough sets. This works only with butter that is cold but pliable, so it stretches with the dough under the rolling pin: soft butter is pressed into the dough and the layers merge, hard butter breaks into pieces and the layers tear. Rolling also stretches the gluten (see the Kneading and gluten card), so the dough rests in the fridge between folds, where the butter firms up and the gluten relaxes; otherwise the dough springs back and shrinks in the oven. Puff pastry is raised by steam alone, croissants and kouign-amann also by yeast; shop-bought puff pastry is often made with fats other than butter, as the ingredient list shows.

How to do it

• Beat the butter between sheets of baking paper into a flat slab and chill it until it bends without cracking but does not smear.
• Flatten yeasted dough for croissants or kouign-amann and chill it before enclosing the butter; warm dough would melt the butter.
• Between folds put the wrapped dough in the fridge for about 20–30 minutes; if the butter starts to smear or show through, return it to the cold sooner.
• Roll briskly in one direction with only a little flour; brush off the excess flour before each fold, otherwise it glues the layers together.
• Cut straight down with a sharp knife and do not brush the cut edges with egg; pressed or glued edges will not rise in the oven.
• Bake in a fully preheated hot oven as the recipe says, usually at least 200 °C, until golden on the inner layers too; thaw frozen bought pastry in the fridge.

If it goes wrong

If the butter breaks through the dough while rolling, dust the spot with flour and chill the dough at once. If the dough springs back and will not roll out, wrap it and leave it in the fridge for 20–30 minutes. Butter running out onto the tray in the oven means the dough was warm or the oven not hot enough; next time chill the shaped pieces before baking and preheat the oven longer. Finish doughy inner layers at a lower temperature with the top covered with foil. Dough in which the butter has merged with the dough will no longer form layers; bake it into savoury straws or biscuits.