Baking Soda vs. Baking Powder

The difference between these two leaveners and when to use each one.

Baking soda is pure sodium bicarbonate and needs an acidic ingredient to activate; baking powder already contains an acid and a base.
Baking soda works immediately when combined with moisture and an acid like lemon juice, vinegar, or buttermilk. Baking powder contains both an acid and a base, so it can work in recipes without extra acidic ingredients. Using one instead of the other can drastically change a recipe's texture and flavor.
Kitchen Tip: If a recipe calls for baking soda but you only have baking powder, you'll need more — and the flavor may be slightly different.