The Difference Between Baking Soda vs. Baking Powder

Baking soda is pure sodium bicarbonate. It needs an acid in the recipe, like buttermilk, lemon juice, or brown sugar, to activate and create lift. Without an acid, it won’t do much in your batter or dough.

Baking powder is a complete leavening system. It contains baking soda, plus a dry acid, usually cream of tartar or tartaric acid, and a little cornstarch to keep it dry. All it needs to work is moisture and heat. 

Most baking powders in the U.S. are double-acting baking powders, which means they react once when mixed and again when baked. Single-acting powders react only once when wet, so bake immediately after mixing.

This means that baking powder-leavened doughs and batters can be stored and baked at a later time, giving you a little wiggle room to prep ahead without losing rise.

What Each One Does in Your Recipe

Both baking soda and baking powder are chemical leaveners. They release gases, primarily carbon dioxide gas, through chemical reactions between acids and bases. I like to think of their effects in 3 main ways: lift, texture, and flavor/color.

Baking Soda

Here’s what happens when I use baking soda:

• Lift: Baking soda releases carbon dioxide as soon as it hits a liquid and an acid. This creates bubbles that expand in the oven, helping my cakes or cookies rise. But because it reacts immediately, I know I need to bake quickly after mixing, especially in wet batters.
• Texture: As the bubbles form, they gently stretch the batter, resulting in baked goods with a slightly more tender crumb. It doesn’t create as soft a crumb as baking powder, but it does make a noticeable difference in cookies, brownies, and quick breads.
• Flavor and color: Baking soda raises pH to promote browning. That’s why cookies spread nicely and get those golden edges. The acid in the recipe neutralizes its flavor. Using too much baking soda may result in an unpleasant metallic, soapy, or bitter taste.

Baking Powder

What does baking powder do? Here’s what happens when I use baking powder:

• Lift: Baking powder works in two stages, once when wet, and again when heated, so it gives batter or dough more stable lift and better bench tolerance. I can mix my muffin batter in the morning and bake it later without worrying about collapse.
• Texture: The small acid content in baking powder lowers the pH slightly, which relaxes gluten and creates softer, more delicate textures. That’s perfect for cakes, muffins, and biscuits.
• Flavor and color: Since it has less alkalinity than baking soda, baked goods are paler and milder in flavor. It won’t create the same browning or spread as baking soda, which is why I sometimes use both to get the best of each.

When to Use Each

If you’re ever unsure which one to grab, I use this simple rule of thumb: look at the ingredients and think about the result you want in your baking recipes.

Use baking soda when:

• There’s an acidic ingredient in the recipe. That includes buttermilk, sour cream, yogurt, brown sugar, unsweetened cocoa powder, lemon juice, honey, or molasses. 
• You want more spread, browning, and crisp edges. Baking soda raises pH, which encourages caramelization and a richer color. That’s perfect for cookies and gingerbread.
• Timing matters. Because it reacts as soon as it hits wet ingredients and acid, I try to bake batters that rely on it right away.

Use baking powder when:

• There’s little or no acid in the recipe. Baking powder already contains its own acid, so it doesn’t need help from other ingredients.
• You need structure and lift. Double-acting baking powder reacts in stages, giving a stable rise and a tender, delicate crumb. That’s great for muffins, biscuits, and cakes.
• You want prep flexibility. Thanks to its bench tolerance, batter or dough with baking powder can sit a little longer before baking without losing leavening power.

Can You Substitute Them?

I get asked this a lot, and the short answer is: not easily. While baking powder contains baking soda, they aren’t interchangeable. Baking soda is about 4 times stronger, so swapping them 1:1 can affect both the texture and flavor of what you’re baking. 

For reference, 1 teaspoon of baking powder will raise a cup of flour, whereas only a 1/4 teaspoon of baking soda can produce the same effect. A general rule of thumb is that 1 teaspoon of lemon juice or vinegar neutralizes ½ teaspoon of baking soda.

I don’t recommend substituting at all in recipes that rely on baking soda for browning and spread, or on baking powder for structure and lift. If a recipe calls for baking soda paired with cream of tartar instead of pre-mixed baking powder, follow it as is, too. This gives more control over lift, browning, and flavor. Snickerdoodles are a classic example.

Why Some Recipes Use Both

Sometimes a recipe uses both baking soda and baking powder because you want the best of both worlds! Baking powder provides reliable lift and structure, while baking soda helps balance acidity and promotes better browning and flavor. 

You’ll often see this combo in recipes that contain some acidic ingredients, but not quite enough to activate baking soda on its own. Pancakes, banana bread, and my Ultimate Chewy Chocolate Chip Cookies are great examples. In these cases, baking soda neutralizes excess acidity and improves color and spread, while baking powder ensures your baked good still rises.

On the flip side, some recipes don’t use either. Recipes containing yeast, baked goods that whip lots of air into the batter, or custard-based desserts may not need baking powder or baking soda. I keep both out of my Best Ever Chewy Brownies for that chewy, fudgy texture!

Why Using the Right Leavener Matters (With Baking Results)

Take a look at my results using the same exact base muffin recipe, baked in the same pans at the same temperature for the same amount of time. The only difference is the chemical leavening agent used:

• Baking powder muffins: These were tall, light, slightly delicate, fluffy, and cakey. They were evenly domed on top. These were my favorites!
• Baking soda muffins: These were slightly more browned, with very tall peaks in the center. They had a somewhat sour aftertaste, almost like there was sour cream in the batter.
• Both baking soda and powder muffins: These muffins were the most browned and caramelized and had a more springy texture.
• No-leavener muffins: These were leaden, dense, rubbery, and really just a doughy, inedible mess.

I repeated the same experiment comparing baking soda vs. baking powder in cookies with my Bakery Style Chocolate Chip Cookie Recipe:

• Baking powder cookies: These were extra thick and tall, not chewy, more fluffy, and not quite as flavorful.
• Baking soda cookies: These cookies were well-browned with slightly crispy edges, chewy interiors, and regular thickness. They were my favorite!
• No-leavener cookies: These were dense and heavy, with a texture similar to that of Mexican wedding cookies. 

How to Tell if Yours Is Still Good

Even if baking soda or baking powder hasn’t hit its expiration date yet, it can still lose effectiveness over time. Air, moisture, and light all weaken chemical leaveners, which is why stale baking soda or baking powder often leads to flat, dense baked goods with little rise.

To test your baking soda, place about 1/4 teaspoon in a small bowl and pour a teaspoon of vinegar over it. If it bubbles up right away, it’s still good. If you see little to no reaction, it’s time to replace it.

To test your baking powder, stir about 1 teaspoon into a cup of hot tap water. Fresh baking powder will bubble noticeably. If nothing happens, it’s no longer effective.

Once opened, it’s best to use both baking soda and baking powder within about 6 to 12 months. If your baked goods aren’t rising as they used to or sinking in the middle, checking the freshness of your leaveners is one of the easiest fixes.

Common Myths

Before you get to baking, I wanted to clear up a few common myths I’ve seen about leavening agents. Understanding these details is one of the easiest ways to avoid baking disasters:

• More baking soda = more rise. Nope. Too much baking soda can create a bitter, metallic taste, and it won’t always make your baked goods rise more.
• Leavening lasts forever. Even before the expiration date, baking soda and baking powder lose potency if exposed to air, moisture, or heat. Old leavening can lead to flat, dense results.
• Double-acting baking powder allows you to prepare hours ahead. It helps with bench tolerance, but it doesn’t make it infinite. Eventually, the first reaction happens, and the batter will start to lose lift if left out too long.

How to Store Leavening Agents

I always store my leavening agents in a cool place in an airtight container. Keep them away from air and light, as they can cause baking powder and baking soda to lose their effectiveness before their expiration date.

Avoid keeping them above the oven or near the dishwasher, where heat and steam can sneak in. Refrigerating them usually isn’t necessary either. It can actually introduce moisture unless the container is perfectly sealed.

If you bake often, it’s best to buy smaller containers and replace them regularly. Fresh leavening agents make a noticeable difference. Using a weak one will result in flat, dense baked goods, even when everything else is done correctly.

More on the Science of Baking: