Processintermediatedraft
Steam leavening (choux, puff pastry)
Also searched as: puff pastry, choux pastry, cream puffs, profiteroles, steam as a raising agent
In short: Water in the dough turns to steam in a hot oven and puffs up hollow spaces. Puff pastry and cream puffs rise without any baking powder.
Picture it
Like a popcorn kernel: the water inside turns to steam and bursts it open.
Level 2 · Puff pastry in the oven≈ 2 mm
Simplified model
What happens
Water expands enormously as it turns to steam. In puff pastry it sits in thin layers of and dough, and the steam pushes the layers apart. In choux pastry a shell forms, which the steam blows up like a balloon.
Why it matters
Explains why these pastries must be baked very hot and why cream puffs collapse if you open the oven too early.
Rules of thumb
- Start very hot, so a lot of steam forms quickly.
- Keep puff pastry cold, so the butter layers stay separate.
- Open the oven only once the pastry is firm and browned.
Levers
1
Temperaturehotter → more steam, more volume
Related entries
Cakes and bakingSources · 1
- Harold McGee: On Food and Cooking (2004), Kapitel Kuchen, Gebäck, Zucker