Air, steam and chemistry: how baked goods rise
Intermediate Kitchen science
Baked goods rise from three gases: air beaten in, steam from water, and carbon dioxide from yeast or baking soda and powder.
Written with AI help from the sources listed, and published by Cory. Spot a mistake? Tell us and we'll fix it.
How do you do it?
- Use baking soda only when the recipe has an acid, such as buttermilk, yogurt, brown sugar, honey or cocoa.
- Bake chemically leavened batters soon after mixing, especially recipes made with baking soda alone.
- Test old leaveners: baking powder should fizz in hot water, baking soda in vinegar.
- For popovers and cream puffs, use a very hot oven so water turns to steam fast.
Why does it work?
Every rise starts with tiny air bubbles beaten in when you cream butter and sugar or whip eggs; no new bubbles form in batter, gases only enlarge the ones already there. Baking soda is alkaline and releases carbon dioxide as soon as it meets an acid and moisture. Baking powder is soda with dry acids already mixed in; most is double-acting, releasing some gas when wet and more when heated. In the oven, water turns to steam, which takes up far more space and puffs popovers, choux and puff pastry. The rise is locked in when egg proteins and starch set. Leftover, unreacted soda tastes soapy and metallic.
What are the common mistakes?
- Swapping baking powder and soda one for one — flat or bitter, soapy results.
- Opening the oven early — steam escapes and puffed items can fall before they set.
Still stuck? Watch someone do it on YouTube.
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