Baking Soda vs Baking Powder: What's the Difference?
Complete guide to chemical leaveners - how they work, when to use each, why some recipes need both, and the science behind fluffy baked goods
Chef Steven Harty
Professional Chef
30+ years experience
30+ years professional experience, trained under Rick Bayless. Specializes in precision cooking.
Education
Culinary Training under Chef Rick Bayless
Quick Answer
Baking soda is pure sodium bicarbonate - it needs an acid (like buttermilk) to activate. Baking powder contains baking soda plus a dry acid, so it only needs liquid to work. Baking soda is 4x stronger, so recipes use less.
What is Baking Soda?
Pure Sodium Bicarbonate
Baking soda is 100% sodium bicarbonate (NaHCO₃). It's a single ingredient - a base (alkaline) that reacts with acids to produce carbon dioxide gas.
Needs an Acid to Work
Baking soda ONLY produces lift when combined with an acidic ingredient like buttermilk, lemon juice, vinegar, yogurt, brown sugar, honey, or cocoa powder.
Single-Acting Leavener
Baking soda reacts immediately when mixed with liquid acid. That's why you must bake items right away - the CO₂ starts releasing as soon as wet meets dry.
What is Baking Powder?
Pre-Mixed Formula
Baking powder contains baking soda PLUS a dry acid (cream of tartar or sodium acid pyrophosphate) and cornstarch to absorb moisture and prevent premature reaction.
Just Add Liquid
Unlike baking soda, baking powder is self-contained. It only needs liquid to activate - no additional acid required in the recipe.
Double-Acting (Usually)
Most baking powders react twice: first when mixed with liquid, second when heated in the oven. This gives you time between mixing and baking.
Side-by-Side Comparison
| Feature | Baking Soda | Baking Powder |
|---|---|---|
| What it is | Pure sodium bicarbonate (NaHCO₃) | Baking soda + dry acid + cornstarch |
| Needs acid? | YES - requires acidic ingredient | NO - self-contained |
| Strength | 4x stronger than baking powder | Milder - needs more |
| Typical amount | ¼ to ½ tsp per cup flour | 1 to 1½ tsp per cup flour |
| Reacts when | Mixed with wet acidic ingredients | Mixed with liquid + heated |
| Timing | Bake immediately | Can wait (double-acting) |
| Browning | Promotes browning | Neutral effect |
| Flavor | Can taste bitter if too much | Neutral taste |
The Chemistry Explained
Baking Soda Reaction
When baking soda (sodium bicarbonate) meets an acid, it produces:
- →Carbon dioxide (CO₂): Creates bubbles = lift
- →Water (H₂O): Adds moisture
- →Salt: Neutral byproduct
Example: Baking soda + buttermilk (lactic acid) = fluffy pancakes
Baking Powder Reaction
Double-acting baking powder reacts in two stages:
- 1First rise (wet): When mixed with liquid - some CO₂ released
- 2Second rise (heat): In oven at ~140°F - more CO₂ released
Why double-acting is better: Gives you time between mixing and baking
Common Acidic Ingredients (that activate baking soda)
Buttermilk
pH 4.4-4.8
Lemon juice
pH 2.0-3.0
Vinegar
pH 2.4-3.4
Yogurt
pH 4.0-4.5
Sour cream
pH 4.5
Brown sugar
pH 5.0 (molasses)
Honey
pH 3.4-6.1
Natural cocoa
pH 5.0-6.0
Cream of tartar
pH 3.0-3.5
Coffee
pH 4.5-5.5
pH below 7 = acidic (lower = more acidic). Baking soda needs these to create CO₂.
When to Use Each One
Baking Soda
Recipe contains acidic ingredients that will react with soda
Common Recipes:
- •Buttermilk biscuits
- •Chocolate cake (natural cocoa)
- •Pancakes with buttermilk
- •Irish soda bread
- •Banana bread
- •Cookies with brown sugar
Baking Powder
Recipe has no significant acidic ingredients
Common Recipes:
- •Sugar cookies
- •Yellow cake
- •Muffins
- •Biscuits (non-buttermilk)
- •Quick breads
- •Scones without buttermilk
Both
Recipe has acid but needs extra lift, or for texture/browning control
Common Recipes:
- •Buttermilk pancakes
- •Red velvet cake
- •Chocolate chip cookies
- •Carrot cake
- •Snickerdoodles
- •Some pound cakes
Why Recipes Use Both
3 Reasons for Using Both
1. Neutralize Excess Acid
Baking soda neutralizes acidic ingredients (buttermilk, citrus, cocoa). Without it, the recipe would taste too tangy.
2. Extra Lift
Baking powder provides additional rise beyond what soda + acid alone would create. Result: lighter, fluffier texture.
3. Better Browning
Baking soda promotes Maillard browning (golden crusts). Cookies with soda spread more and get crispy edges.
🍪 Classic Example: Chocolate Chip Cookies
- •Brown sugar contains molasses (acidic) → needs baking soda to neutralize
- •Baking soda promotes browning → crispy edges, golden color
- •Baking powder adds extra lift → chewy, thick centers
⚠️ Don't Overdo It
More leavener ≠ more rise. Too much causes:
- • Bitter, metallic, soapy taste
- • Coarse, open crumb texture
- • Rise then collapse in the oven
- • Over-browning or burning
Substitution Guide
Solution
Cannot substitute directly - baking powder won't neutralize acids in recipe
Ratio
N/A - must add acid
Note
Add cream of tartar or use buttermilk
Solution
¼ tsp baking soda + ½ tsp cream of tartar
Ratio
Makes 1 tsp baking powder
Note
Mix fresh each time - doesn't store well
Solution
Whipped egg whites (for some recipes)
Ratio
Varies by recipe
Note
Only works for recipes where texture allows
📏 Quick Reference
To make 1 tsp baking powder:
¼ tsp baking soda + ½ tsp cream of tartar
Baking powder → Baking soda:
Use ¼ the amount (1 tsp powder = ¼ tsp soda + acid)
Storage & Freshness Testing
Testing Baking Soda
Add ¼ tsp baking soda to 2 tsp vinegar
✓ Good
Immediate vigorous bubbling
✗ Bad
Weak or no reaction
Testing Baking Powder
Add 1 tsp baking powder to ⅓ cup hot water
✓ Good
Active fizzing and bubbles
✗ Bad
Little or no activity
Storage Guidelines
| Item | Where to Store | How Long |
|---|---|---|
| Baking Soda (unopened) | Pantry | Indefinitely (doesn't expire) |
| Baking Soda (opened) | Airtight container | 6 months for baking |
| Baking Powder (unopened) | Pantry | 18 months - 2 years |
| Baking Powder (opened) | Airtight, cool & dry | 6 months |
💡 Pro Tip: Mark the opening date on your containers. When in doubt, test before baking! Old leaveners are the #1 cause of flat baked goods.
Frequently Asked Questions
Can I substitute baking soda for baking powder?
Yes, but not directly. For 1 teaspoon baking powder, use ¼ teaspoon baking soda plus ½ teaspoon cream of tartar. You can't substitute baking powder for baking soda without adding an acid to the recipe.
Why do some recipes use both baking soda and baking powder?
Recipes use both when they need extra lift (baking powder) while also having acidic ingredients that need neutralizing (baking soda). The baking soda also promotes browning and creates a slightly different texture.
How long does baking powder last?
Unopened baking powder lasts 18 months to 2 years. Once opened, it loses potency after 6 months. Always test before using in important recipes by adding to hot water - if it bubbles vigorously, it's still good.
What happens if I use too much baking soda?
Too much baking soda creates a bitter, soapy metallic taste and can cause over-browning. It may also cause baked goods to rise too quickly then collapse. The excess soda that doesn't react with acid tastes unpleasant.
Is baking soda the same as bicarbonate of soda?
Yes! Baking soda, bicarbonate of soda, bicarb, and sodium bicarbonate are all the same thing - pure NaHCO₃. In the UK and Australia it's typically called bicarbonate of soda, while in the US it's called baking soda.
Chef Steven Harty
Professional Chef | 30+ Years Experience
Chef Harty brings over 30 years of professional culinary experience, having trained under renowned chef Rick Bayless. He specializes in precision cooking and measurement accuracy, ensuring all our cooking conversions and ingredient calculations are tested and verified in real kitchen conditions.
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