To Make Baking Powder (521) Posted on December 16, 2025December 16, 2025 By gaylascookbook_itw6oh 2 teaspoonfuls cream tartar. 1 teaspoonful baking soda. 1 teaspoonful corn starch. Mix all together by sifting and it is ready for use. Whitehead’s Family Cook Book, 1891 Pantry