According to Food.com, cooks and bakers can make self-rising flour at home by adding baking powder and salt to whole-grain flour. For every cup of whole-grain flour, a cook needs to add 1 1/4 teaspoons of baking powder and between 1/4 and 1/2 teaspoon of salt.
One cup of whole-grain flour weighs 140 grams or 4 7/8 ounces. Weighing flour is a more accurate way of measuring ingredients than using cups. To create well-mixed self-rising flour for use in a recipe, combine the whole-grain flour, baking powder and salt in an airtight box and shake vigorously. This homemade self-rising flour can be used immediately or stored for later use.
According to Food.com, 1 teaspoon of baking powder can be substituted by 1/2 teaspoon of cream of tartar and 1/4 teaspoon of baking soda. Commercial baking powder is a mixture of baking soda, cream of tartar and cornstarch. Baking powder releases carbon dioxide bubbles when combined with liquid, which can cause bread and other types of baked goods to rise. It is an essential ingredient in many bread and cake recipes.
The same combination of ingredients (1 cup flour, 1 1/4 teaspoons baking powder, 1/4 teaspoon salt) can be used to make self-rising flour from all-purpose white flour.