I am making a pancake recipe that calls for 2 teaspoons of baking powder, which I do not have.
I was wondering if it would be ok to use baking soda as a substitute, and if so, how much would I need to use?
Baking powder contains baking soda, plus acidic ingredient(s).
If you have cream of tartar, you can make baking powder directly:
Without cream of tartar, you can substitute baking soda for baking powder as long as you have an acid in your recipe, like buttermilk. If your recipe does not contain an acid, you should add one or the baking soda will remain inert. Based on the above proportions, you should be able to substitute 1/2 tsp baking soda + acid for 2 tsp baking powder.
For pancakes specifically, if you rest your batter, you should fold in the baking soda at the end so you do not lose all the leavening action.
Baking powder and baking soda ARE NOT THE SAME THING.
Baking powder is a mix of soda and an acid that reacts to produce gas that will leaven (rise) the cake.
Baking soda is only 1/2. It has a high pH which will cause proteins to be weak and also cause the cakes to be dark.
Cream of Tartar is an acid which will react with the soda to help produce gas. It will work, but it is not the best as the neutralizing value and rate of reaction is different. It is better to go buy the ingredient you need instead of trying to reverse engineer. Most baking powders are design to give off a little gas in the bowl to lighten the batter and the majority of the gas is produced in the oven after about 40% of the cooking process to allow the product to rise in the oven. Cream of tartar reacts very fast and will gas mostly in the bowl