Question: how much baking powder do you need?
Answer: To test baking soda's effectiveness: mix 1/4 teaspoon baking soda with 2 teaspoons of vinegar and the mixture should bubble immediately. Note: The general rule of thumb for amount of baking powder in recipes: 1 to 2 teaspoons (5-10 grams) of baking powder leavens 1 cup (140 grams) of flour.