I started making my own baking powder for the last couple months. I found a recipe and was always unsure of the baking powder ingredients as I knew you could get "aluminium free" baking powder and was concerned about those with aluminium. Also I knew you can get "gluten free" baking powder and that left me to wonder again about what was actually in the baking powder.
I'm glad I did get into the habit of making my own. This week we discovered in the community kitchen the ingredients for baking powder did indeed have wheat. Good thing I used my own stuff at home. Now we'll just need to supply some for the main kitchen.
So how do I do it? It's just another one of the great recipes from "Nourishing Traditions."
I use 1 part Baking Soda, 2 parts Cream of Tartar and 2 parts Arrowroot (you can use corn starch, I did once, but didn't really like the thought of it since a lot of corn is genetically modified, and then I found out our corn starch here has wheat in it - go figure). Shake well.
It works best if you add it to your goods right before baking. (For those who soak their grain goods).