The main ingredients that cause dough to rise are yeast, baking soda, and baking powder. All three work by producing carbon dioxide gas, which forms tiny bubbles inside the dough or batter and causes it to expand. Which one a recipe uses depends on what you’re baking, how much time you have, and what other ingredients are in the mix.
Yeast: The Living Leavener
Yeast is a single-celled fungus that feeds on sugar. As it digests glucose, it produces carbon dioxide and a small amount of alcohol. The CO2 gets trapped inside the dough, inflating it like thousands of tiny balloons. The alcohol evaporates during baking. This is the process behind every loaf of bread, pizza crust, and cinnamon roll that needs time to rise before it goes in the oven.
Because yeast is alive, it’s sensitive to temperature. It thrives in warm environments, which is why most bread recipes call for water between 100°F and 110°F when activating dry yeast. Cold temperatures slow it down (useful for overnight rises in the fridge), and temperatures above roughly 130°F to 140°F kill it outright. If your dough isn’t rising, the water you used may have been too hot.
Yeast-based doughs typically need anywhere from one to several hours to rise, sometimes with a second rise after shaping. That long fermentation is also what develops the complex, slightly tangy flavor you associate with good bread.
Baking Soda and Baking Powder
When you don’t have hours to wait, chemical leaveners do the job almost instantly. Both baking soda and baking powder rely on the same active compound: sodium bicarbonate. The difference is what triggers the reaction.
Baking soda is pure sodium bicarbonate. It needs an acid to react. When it meets something acidic in your batter, like buttermilk, lemon juice, yogurt, or brown sugar, it releases one molecule of carbon dioxide for every molecule of sodium bicarbonate. That reaction starts immediately, which is why recipes using baking soda often tell you to get the batter into the oven quickly.
Baking powder is sodium bicarbonate pre-mixed with a powdered acid (usually cream of tartar). It only needs moisture and heat to activate, so it works in recipes that don’t contain any acidic ingredients. Most baking powder sold today is “double acting,” meaning it releases some gas when it gets wet and another burst when it hits oven heat. This gives you a little more flexibility with timing.
A simple rule: recipes with an acidic ingredient tend to call for baking soda. Recipes without one use baking powder. Some recipes use both to balance flavor and lift.
Substituting One for the Other
If you’re out of baking soda, you can use baking powder instead, but you’ll need about three times as much because baking powder is diluted by its added acid. So 1 teaspoon of baking soda becomes 3 teaspoons of baking powder. Going the other direction is trickier. Baking soda is much stronger, and you’d need to add your own acid (like cream of tartar) to make it work in a recipe designed for baking powder.
Testing if Your Leavener Is Still Fresh
Chemical leaveners lose potency over time, especially once opened. To test baking soda, drop a quarter teaspoon into a cup with two teaspoons of vinegar. If it bubbles vigorously, it’s fine. For baking powder, stir half a teaspoon into a cup of hot water. You should see bubbles right away. No bubbles means it’s time to replace it.
Steam: The Overlooked Third Option
Not all rising comes from yeast or chemical leaveners. In pastries like puff pastry, choux (used for éclairs and cream puffs), and popovers, steam does the heavy lifting. These recipes rely on thin layers of butter or water trapped within the dough. When the oven heats up, that water rapidly converts to steam, expanding to many times its liquid volume and pushing the layers apart. Puff pastry, for example, uses alternating layers of dough and butter that are rolled extremely thin. The steam inflates each layer individually, creating that signature flaky texture with no yeast or baking powder involved.
All baked goods benefit from steam to some degree. Even in yeast breads, water vapor contributes to the final push of expansion in the oven, a phase bakers call “oven spring.”
Why Gluten Matters for Rising
Carbon dioxide can only make dough rise if something traps it. In wheat-based doughs, that something is gluten. When flour mixes with water, two proteins (gliadin and glutenin) combine to form a stretchy, elastic network. This network wraps around each gas bubble, holding it in place as it expands. Without gluten, the gas would simply escape through the surface.
The gluten network needs to strike a balance. If it’s too weak, it ruptures under the pressure of expanding gas and the dough collapses. If it’s too strong, it resists stretching and the dough can’t expand fully. This is why bread recipes call for high-protein flour (more gluten development) while cake recipes use lower-protein flour (a softer, more tender crumb). It’s also why kneading matters: working the dough strengthens the gluten network so it can hold more gas and produce a taller, airier loaf.
Self-Rising Flour: Leavener Built In
Self-rising flour is simply all-purpose flour with baking powder and salt already mixed in. The standard ratio is 1 cup of flour, 1½ teaspoons of baking powder, and ¼ teaspoon of fine salt. It’s common in biscuit and quick bread recipes. If a recipe calls for self-rising flour and you only have all-purpose, just add the baking powder and salt yourself in those proportions.
Adjusting Leaveners at High Altitude
If you bake above 3,000 feet, you’ll likely need to reduce your leavening agents. Lower air pressure at high altitude means gas bubbles expand more easily, which sounds helpful but actually causes baked goods to rise too fast, then collapse. At 3,000 feet, reduce baking powder by ⅛ teaspoon for each teaspoon the recipe calls for. At 5,000 feet, reduce by ⅛ to ¼ teaspoon. At 7,000 feet, reduce by a full ¼ teaspoon per teaspoon. Start with the smaller reduction and adjust from there. You’ll often need to increase liquid slightly as well, since water evaporates faster at higher elevations.