I started making my own baking powder when I heard that some baking powders contain aluminium. I didn’t want to be eating that. Also, baking powder contains gluten in the form of wheaten cornflour. Some of my family members are coeliac and I like to bake for them, so I need a gluten-free baking powder. That is also aluminium free. And ideally doesn’t come in plastic.
Turns out, baking powder is the easiest thing to make in the world. You need just two ingredients, cream of tartar and bicarbonate of soda. The ratio is 2:1 so 2 teaspoons of cream of tartar needs 1 teaspoon of bicarb.
Mix them together and voila! You have super easy baking powder. Store in a jar in the cupboard until needed.
Some recipes also add 1 part cornstarch too, which means cornflour, but as cornflour is actually made of wheat and not corn (bizarrely) I don’t add this. I have seen a gluten-free cornflour available that is actually made with corn so at some point I might try it, but I think it works fine without.
What else do you need to know? It has a slight tendency to clump because it hasn’t got caking agents added. This isn’t a problem of course, just give the mix a good stir before you use it.
The other great thing is that you can make small batches as you need it, so it doesn’t sit in the cupboard slowly going out of date. No matter how much baking I do, I’ve never been able to use up an entire container of baking powder before I exceed the expiry date, so this suits me much better.