Baking Powder Substitute

Making baking powder from pantry ingredients

Baking powder is a base (baking soda) plus a dry acid, and a small amount of starch to keep it dry. If you are out of it, you can make a working substitute from baking soda and cream of tartar, which is the dry acid in many commercial products. This page mixes them in a one to two ratio, one part baking soda to two parts cream of tartar.

Homemade baking powder acts differently from the store-bought kind. Most commercial baking powder is double-acting, which means it releases some gas when it gets wet and more when it is heated. A mix of soda and cream of tartar acts mostly as soon as it gets wet, so make the batter and get it into the oven without letting it sit. Because there is no starch in the mix, it will also start reacting as it absorbs moisture from the air, which is why it should be mixed fresh and not stored.

If you have no cream of tartar, another route is to use baking soda with an acidic liquid already in the recipe, such as buttermilk or yogurt, but that changes the recipe itself and is not covered by this calculator.

How this calculator works

Each substitute uses a tested ratio: baking powder from cream of tartar and baking soda (2:1), baking soda stepped up to baking powder (1:3, since baking soda is several times stronger), cake flour from all-purpose flour with a portion swapped for cornstarch, and self-rising flour from all-purpose flour with baking powder and salt whisked in.

Where these numbers come from

These are standard, widely-used baking substitution ratios drawn from baking science references and consistent across professional and home-baking sources.

• Baking powder (cream of tartar + baking soda, 2:1 ratio)
• Baking soda to baking powder (1:3 ratio, accounting for baking soda's greater strength)
• Cake flour (all-purpose flour with 2 tbsp per cup swapped for cornstarch)
• Self-rising flour (1 cup all-purpose flour + 1.5 tsp baking powder + 1/4 tsp salt)

Source: Standard baking-science substitution ratios, consistent across test-kitchen and baking-reference sources. A substitute changes texture slightly in some recipes -- these ratios get you functionally close, not identical.