Baking Soda and Cream of Tartar (Best Option)
1/4 teaspoon baking soda + 1/2 teaspoon cream of tartar per 1 teaspoon baking powderThis combination works because baking soda is a base and cream of tartar is an acid; together they create carbon dioxide gas when moistened, which aerates the meatloaf mixture. This mimics the action of baking powder, ensuring the meatloaf remains tender and slightly airy.
To use effectively, mix the baking soda and cream of tartar thoroughly into the dry ingredients before combining with wet ingredients. Avoid letting the mixture sit too long before cooking to prevent loss of leavening power.
Compared to commercial baking powder, this substitute provides a fresher and more controlled rise, resulting in a meatloaf that is less dense and has a better crumb structure.