Baking soda vs baking powder: which to use
They look alike in the spoon, but they need different conditions to make your baking rise. Check the recipe before reaching for the other tub.
Quick answer
Baking soda vs baking powder comes down to acid. Baking soda is pure sodium bicarbonate and needs an acidic ingredient, such as buttermilk or lemon, to release gas. Baking powder contains its own dry acid plus starch and works with moisture and heat. Soda is about 3-4 times stronger, so swapping them spoon for spoon can change the rise, flavor and browning.
Compare what each one does
| Property | Baking soda | Baking powder |
|---|---|---|
| Contents | Pure sodium bicarbonate | Baking soda, a dry acid and starch |
| What starts the reaction | Moisture and acid in the recipe | Moisture; most US powders also react again with oven heat |
| Relative strength | About 3-4 times stronger than baking powder | Use the larger amount stated in the recipe |
| What excess can do | Taste soapy or metallic and cause too much browning | Change the flavor and the recipe's intended rise |
Both release carbon dioxide, which forms bubbles in batter or dough. Most US baking powder is double-acting: it reacts once when wet and again in the oven. You don't need to add lemon or yogurt solely to activate it.
Swap with the acid in mind
If you're out of baking powder, soda alone won't give the same result. Cream of tartar supplies the acid for the replacement below. Measure both powders separately and add them with the dry ingredients. Once the batter is mixed, get it into the oven promptly.
| Missing ingredient | Replacement | What to expect |
|---|---|---|
| 1 teaspoon (4.9 ml) baking powder | 1/4 teaspoon (about 1.2 ml) baking soda plus 1/2 teaspoon (about 2.5 ml) cream of tartar | The cream of tartar supplies acid; mix and bake promptly |
| 1 teaspoon (4.9 ml) baking soda | About 3 teaspoons (14.8 ml) baking powder | Flavor may change and the bake may brown less |
The second swap is a fallback. It adds the acid already in baking powder to a recipe designed for soda, so the balance changes. For a cake you need to turn out a particular way, buying the listed ingredient or choosing another recipe is the safer choice.
Keep the recipe's acidic ingredients
Buttermilk, yogurt and lemon can react with baking soda. Brown sugar, natural cocoa and honey can also supply acid. If you change those ingredients, you may change how much soda reacts and how much remains in the finished bake.
That matters when replacing buttermilk with plain milk. Milk alone won't supply the same acidity; choose an acidic buttermilk substitute instead. Treat an egg change separately, too: an egg substitute for baking has to suit the egg's job in that recipe.
Some recipes use both soda and powder. The soda reacts with acidic ingredients and affects browning; the powder supplies more lift. Keep both amounts as written unless you're following a tested variation.
Names to look for abroad
| Country | Baking soda | Baking powder |
|---|---|---|
| UK | Bicarbonate of soda, often called bicarb | Baking powder |
| Germany | Natron | Backpulver |
| France | Bicarbonate de soude, labeled alimentaire | Levure chimique |
| Spain | Bicarbonato sódico | Levadura química; polvo de hornear in Latin America |
| Italy | Bicarbonato di sodio | Lievito per dolci, often vanilla-flavored |
| Indonesia | Soda kue or baking soda | Baking powder |
| Brazil | Bicarbonato de sódio | Fermento químico em pó |
German Backpulver often comes in packets measured for 500 g (about 1.1 lb) of flour, with about 15 g (about 1/2 oz) of powder in a packet. Read the packet instructions. A packet isn't a universal spoon measure, and a recipe from another country may assume a different amount.
Yeast is a separate ingredient. Hefe, levure de boulanger, levadura de panadería, lievito di birra and fermento biológico are names for yeast. They won't replace baking powder in a quick cake batter.
Test the tub before mixing
Put a little baking powder in hot water: it should fizz. Test baking soda with vinegar instead. Using plain water to test soda can make a working ingredient look inactive because the test is missing acid.
If the ingredient doesn't fizz in the right test, replace it before baking. Adding more of an inactive powder won't reliably fix the rise. Keep both containers dry and close them after measuring.
Avoid a heavy spoonful
Level the measuring spoon instead of leaving a mound on top. Extra soda can leave a soapy or metallic taste and make the outside too brown. If a batch tastes wrong, check the amount and the ingredient label before changing the oven temperature.
Questions
Can I substitute baking soda for baking powder?
Yes, with added acid: replace 1 teaspoon (4.9 ml) baking powder with 1/4 teaspoon (about 1.2 ml) baking soda plus 1/2 teaspoon (about 2.5 ml) cream of tartar. Avoid a spoon-for-spoon swap of soda alone.
Can I use baking powder instead of baking soda?
Use about 3 times as much baking powder as baking soda. Expect a possible flavor change and less browning, since you are changing the acid balance as well as the raising agent.
What is baking soda called in the UK?
Look for bicarbonate of soda, often shortened to bicarb. Baking powder keeps the name baking powder.
Which is better for cookies, baking soda or baking powder?
Use the one the recipe specifies. Soda affects browning and reacts with acidic ingredients; powder brings its own acid, so changing between them can change the cookies.
Why does a recipe call for both?
The soda reacts with acid already in the recipe, while baking powder supplies additional lift. Using both can help the recipe get its intended rise and browning.
Keep reading
- Ingredient substitutesButtermilk substitute for baking and marinadesMake a buttermilk substitute with milk and lemon juice, or use yogurt, kefir or a dairy-free option. Get ratios for baking and chicken marinades.
- Free kitchen toolsCups to grams for the recipe in front of youConvert cups to grams by ingredient, with worked examples for flour and sugar. Check US and metric cup sizes, measuring methods and butter amounts.
- Ingredient substitutesEgg substitute for baking: choose by the recipeChoose an egg substitute for baking with flax, applesauce, banana, aquafaba or yogurt. Get amounts per egg and learn which recipes need real eggs.