Difference Between Baking Soda and Baking Powder

Baking soda and baking powder are both leavening agents used in baking to help baked goods rise, but they have different chemical compositions, properties, and uses. Here is the key difference between Baking Soda and Baking Powder:

1. Chemical Composition

Baking Soda

Pure sodium bicarbonate (NaHCO₃).
Also known as bicarbonate of soda.

Baking Powder

Contains sodium bicarbonate along with an acidifying agent (usually cream of tartar) and a drying agent (usually starch).
Comes in two types: single-acting (reacts once when moistened) and double-acting (reacts twice, once when moistened and again when heated).

2. Mechanism of Action

Baking Soda

Requires an acidic ingredient (like lemon juice, vinegar, buttermilk, or yogurt) and moisture to activate.
Produces carbon dioxide (CO₂) gas when it reacts with the acid, causing the dough or batter to rise.

Baking Powder

Contains both an acid and a base, so it only requires moisture to activate.
Double-acting baking powder releases some CO₂ gas when mixed with wet ingredients and more CO₂ gas when heated in the oven.

3. Taste

Baking Soda

Has a slightly bitter, alkaline taste.
Must be used in recipes that include an acidic ingredient to neutralize its flavor.

Baking Powder

Generally neutral in taste due to the balanced acidic and basic components.
Can be used in recipes without any additional acidic ingredients.

4. Usage in Recipes

Baking Soda

Used in recipes that already contain acidic ingredients.
Commonly found in recipes for cookies, pancakes, muffins, and quick breads.

Baking Powder

Used in recipes that do not contain acidic ingredients.
Commonly found in recipes for cakes, biscuits, and other baked goods that require a neutral rise.

5. Amount Needed

Baking Soda

More potent than baking powder; typically, only a small amount is needed (1/4 teaspoon can leaven about 1 cup of flour).

Baking Powder

Less potent than baking soda; more is required to achieve the same leavening effect (1 teaspoon can leaven about 1 cup of flour).

6. Substitution

Baking Soda

If substituting for baking powder, use one part baking soda and two parts cream of tartar, or add an acidic ingredient to the recipe.

Baking Powder

If substituting for baking soda, you generally need to use about three times the amount of baking powder, but this may not always be advisable due to the change in flavor and texture.

7. Shelf Life

Baking Soda

Has a long shelf life if kept dry.
Should be tested for potency if it has been stored for a long time by adding a small amount to vinegar to see if it bubbles vigorously.

Baking Powder

Has a shorter shelf life compared to baking soda, especially if it is double-acting.
Should be tested for potency by adding a small amount to hot water to see if it bubbles vigorously.

8. Examples in Baking

Baking Soda