Baking Powder vs. Baking Soda

Baking Powder vs. Baking Soda: Which One to Use and Why
By Sergio Boulanger

When it comes to creating light, fluffy baked goods, the leavening agent you choose can make a world of difference. Baking powder and baking soda—also known as sodium bicarbonate—are two common leaveners that often cause confusion for both new and experienced bakers. While they both produce carbon dioxide (CO₂) to help doughs and batters rise, their chemistry and applications differ significantly. In this blog post, we’ll clarify these differences and demonstrate them with two versions of a simple scone recipe—one using baking soda and the other using baking powder.

1. What Is Baking Soda?

Baking soda, or sodium bicarbonate, is a base that requires an acidic ingredient (like yogurt, buttermilk, lemon juice, or cream of tartar) to trigger the release of carbon dioxide gas. This gas expands in the oven’s heat, creating bubbles that leaven the dough or batter.

Key Points About Baking Soda

• Requires an Acid: Without an acidic ingredient, baking soda won’t activate sufficiently, and your baked goods may remain dense or taste soapy.

• Quick Reaction: Once combined with acid, baking soda reacts immediately, so most doughs or batters should be baked quickly.

• Potential Aftertaste: Overusing baking soda can impart a metallic or bitter flavor if there isn’t enough acid to neutralize it.

2. What Is Baking Powder?

Baking powder is a pre-mixed leavening agent that contains baking soda, an acid (often cream of tartar), and a filler or drying agent like cornstarch. This blend is formulated so you don’t need an external acid to activate it. Many common baking powders are double-acting, meaning they release gas twice: once when the powder is moistened and again when exposed to heat in the oven.

Key Points About Baking Powder

• Self-Contained Acid: No additional acidic ingredient is required; it already contains the acid to neutralize the baking soda.

• Double-Acting: Provides a second rise in the oven, leading to a more consistent leavening effect.

• Neutral Flavor: Less risk of a soapy or bitter taste compared to an overuse of baking soda.

3. Comparing Baking Soda and Baking Powder

1. Chemical Composition:

   • Baking Soda: Base (sodium bicarbonate).

   • Baking Powder: Sodium bicarbonate plus an acid (cream of tartar) and cornstarch.

2. Acid Requirement:

   • Baking Soda: Needs an external acid (e.g., buttermilk, vinegar) to activate.

   • Baking Powder: Contains its own acid, so no additional acidic ingredient is needed.

3. Leavening Strength:

   • Baking Soda: Typically stronger, gram-for-gram, but only if there’s enough acid in the recipe.

   • Baking Powder: Generally milder, but consistent because of its built-in acid.

4. Flavor:

   • Baking Soda: This can leave a soapy or metallic taste if not fully neutralized by acid.

   • Baking Powder: Usually imparts minimal flavor impact unless overused.

5. Reaction Timing:

   • Baking Soda: Reacts immediately upon contact with acid; bake promptly.

   • Baking Powder: Often double-acting, providing some leavening at room temperature and additional lift in the oven’s heat.

4. Scones Recipe: Baking Soda vs. Baking Powder

To highlight the differences, here’s the same scone recipe split into two versions: one uses baking soda with an acidic ingredient (buttermilk), while the other uses baking powder in a more neutral environment. Notice how the ingredients and instructions vary slightly to accommodate the leavening agent.

A. Baking Soda Scones (Buttermilk Scones)

Yield: 8 scones

Ingredients

• 250g (2 cups) all-purpose flour

• 2 tablespoons granulated sugar

• 1 teaspoon salt

• ½ teaspoon baking soda

• 85g (6 tablespoons) cold unsalted butter, cut into small pieces

• 180ml (¾ cup) buttermilk (provides the acid needed for baking soda)

Method

1. Preheat Oven: Preheat to 220°C (425°F). Line a baking sheet with parchment paper.

2. Combine Dry Ingredients: In a large bowl, whisk together flour, sugar, salt, and baking soda.

3. Cut in Butter: Add cold butter pieces. Use a pastry blender or rub the butter into the flour until the mixture resembles coarse crumbs.

4. Add Buttermilk: Pour the buttermilk into the dry mixture. Stir gently until the dough comes together; avoid overmixing.

5. Shape the Dough: Turn the dough onto a lightly floured surface. Pat into a circle about 2–2.5 cm (¾–1 inch) thick.

6. Cut Scones: Use a round cutter or knife to cut into 8 wedges or circles.

7. Bake: Transfer scones to the lined baking sheet. Bake for 12–15 minutes, or until they’re golden brown on top.

8. Cool and Serve: Let them cool slightly on a wire rack before serving warm with butter or jam.

Outcome:
These baking soda scones rely on the acidity of buttermilk for activation. You’ll get a soft, tender crumb with a slight tang from the buttermilk.

B. Baking Powder Scones (Classic Cream Scones)

Yield: 8 scones

Ingredients

• 250g (2 cups) all-purpose flour

• 2 tablespoons granulated sugar

• 1 teaspoon salt

• 2 teaspoons baking powder

• 85g (6 tablespoons) cold unsalted butter, cut into small pieces

• 180ml (¾ cup) heavy cream (provides richness but minimal acidity)

Method

1. Preheat Oven: Preheat to 220°C (425°F). Line a baking sheet with parchment paper.

2. Combine Dry Ingredients: In a large bowl, whisk together flour, sugar, salt, and baking powder.

3. Cut in Butter: Add cold butter pieces. Use a pastry blender or rub the butter into the flour until the mixture resembles coarse crumbs.

4. Add Cream: Slowly pour the heavy cream into the dry mixture. Stir gently just until the dough forms.

5. Shape the Dough: Turn the dough onto a lightly floured surface. Pat into a circle about 2–2.5 cm (¾–1 inch) thick.

6. Cut Scones: Use a round cutter or knife to cut into 8 wedges or circles.

7. Bake: Transfer scones to the lined baking sheet. Bake for 12–15 minutes, or until golden brown on top.

8. Cool and Serve: Let them cool slightly on a wire rack before enjoying them warm.

Outcome:
These baking powder scones have a milder flavor and rely on the pre-mixed acid in the baking powder. The texture is tender, and the flavor is more neutral, allowing you to add additional flavorings (like vanilla or lemon zest) if desired.

5. Comparing Results of the Two Scones

• Rise:

  • Baking Soda (Buttermilk Scones): Often rise with a slightly tangy flavor and a moist, tender interior.

  • Baking Powder (Cream Scones): Provide a more neutral flavor base and a consistent rise without relying on external acid.

• Flavor:

  • Baking Soda Scones: Subtle tang from the buttermilk compliments the rich butter flavor.

  • Baking Powder Scones: Mild and easily adaptable to sweet or savory additions.

• Texture:

  • Both yield tender, flaky scones, but the buttermilk scones may feel slightly lighter due to the additional reaction from the acid.

6. Tips for Baking with Baking Soda vs. Baking Powder

1. Check Freshness

   • Both baking soda and baking powder lose potency over time; test them regularly for leavening power.

2. Mind the Ratios

   • Baking soda is stronger, gram-for-gram, than baking powder. Adjust your recipe accordingly if you’re substituting.

3. Acid is Key

   • Baking soda requires an acidic ingredient to work properly, while baking powder contains its own acid.

4. Store Properly

   • Keep both baking soda and baking powder in airtight containers in a cool, dry place.

7. Frequently Asked Questions

Q: Can I use baking powder instead of baking soda, or vice versa?
A: While possible, you need to adjust for the fact that baking powder already contains acid, whereas baking soda needs an acid. You may also need to alter the recipe’s liquid and flavor balance.

Q: Why does my batter taste bitter when I use baking soda?
A: This typically means there wasn’t enough acid to neutralize the baking soda. Try increasing acidic ingredients like buttermilk or lemon juice.

Q: Do baking powder and baking soda affect color?
A: Yes. Baking soda can help with browning (due to higher pH), while baking powder provides an even lift and can sometimes help with color, but to a lesser degree.

8. Final Thoughts

While baking powder and baking soda both serve as chemical leaveners, they differ in composition and the conditions they require to release carbon dioxide. Baking soda is best used when there’s sufficient acid in the recipe, offering a quick reaction and often lending a subtle tang. Baking powder, on the other hand, is a self-contained leavening agent that doesn’t rely on external acid.

By understanding when and how to use each, you can precisely control the flavor, rise, and texture of your baked goods. The two scone recipes above highlight these differences, demonstrating how one ingredient can completely change the taste and mouthfeel of an otherwise identical recipe.

Happy Baking!

— Sergio Boulanger, Art Bakery & Gourmet