Question: how much baking soda for 1 tablespoon baking powder?
Answer: Baking soda is much stronger than baking powder. To make baking powder, mix one part baking soda and two parts cream of tartar. So, if you recipe calls for 1 tablespoon of baking powder, use 1 teaspoon of baking soda, mixed in with 2 teaspoons of cream of tartar.