How this instrument works
Self-rising flour is plain flour with leavening already built in — baking powder and salt are pre-mixed into the flour at the mill, so a baker doesn't need to measure them separately every time. It's common in Southern US baking traditions for biscuits, quick breads, and some cakes, and it's also typically milled from a lower-protein soft wheat than standard all-purpose flour, giving a more tender crumb.
When a recipe calls for self-rising flour and a kitchen only has all-purpose on hand, the fix is simple and standardized: whisk 1½ teaspoons of baking powder and ¼ teaspoon of salt into every cup of all-purpose flour, then use the result exactly as the recipe specifies self-rising flour. Because the ratio is fixed per cup, it scales linearly to whatever quantity a recipe needs.
This substitute isn't perfectly identical to milled self-rising flour, since it doesn't replicate the softer, lower-protein wheat that commercial self-rising flour typically uses — the leavening and salt content match exactly, but the texture of the finished baked good may come out very slightly less tender than the same recipe made with true self-rising flour.
- Enter the amount your recipe calls for as All-purpose flour (cups).
- Read Baking powder (tsp) and Salt (tsp) together — both are added to the same measured flour.
- Whisk the baking powder and salt thoroughly into the flour before using — even distribution matters for even rising.
- If your recipe also lists separate baking powder or salt amounts, skip adding those separately — this substitute already includes them, so add only what the recipe calls for above and beyond this ratio, if anything.
Worked example — 1 cup of all-purpose flour
A biscuit recipe calls for 1 cup of self-rising flour, but the kitchen only has all-purpose on hand. Applying the substitution ratio: baking powder = 1 × 1.5 = 1.5 tsp, and salt = 1 × 0.25 = 0.25 tsp.
Whisking 1.5 teaspoons of baking powder and 0.25 teaspoons (a scant quarter teaspoon) of salt into the 1 cup of all-purpose flour produces a substitute that can be used exactly as the recipe's 1 cup of self-rising flour, with no other adjustment needed to the rest of the recipe.
Questions
Can I use baking soda instead of baking powder for this substitute?
No — baking soda needs an acidic ingredient in the recipe (like buttermilk or lemon juice) to activate and produce lift, while baking powder already contains its own acid and reacts on its own with liquid and heat. Self-rising flour is specifically leavened with baking powder for that reason, so substituting baking soda in this ratio would leave a recipe under-leavened unless the rest of the recipe already supplies the missing acid.
Is homemade self-rising flour exactly the same as store-bought?
Close, but not identical — the leavening and salt content match the commercial standard exactly, but commercial self-rising flour is typically milled from a lower-protein soft wheat than all-purpose flour, giving a slightly more tender result in biscuits and quick breads. The homemade substitute performs very similarly and works well in most recipes, with only a marginally less tender crumb as the practical difference.
Do I need to sift the baking powder and salt into the flour?
Sifting isn't strictly required, but thoroughly whisking the three ingredients together is important — uneven distribution can leave pockets of concentrated baking powder that taste bitter or metallic, or patches with too little leavening that don't rise properly. A few dozen seconds of whisking, or one pass through a sieve, is usually enough to distribute it evenly.
Can I make a big batch of this substitute ahead of time?
Yes — scale the ratio up (for example, 6 cups flour, 9 tsp baking powder, 1.5 tsp salt) and store the mixed flour in an airtight container. Baking powder does slowly lose potency over time even sealed, so a batch made more than a few months ahead may rise slightly less strongly than a freshly-mixed one; check your baking powder's own expiration date as the limiting factor.
What if my recipe already lists baking powder and salt separately alongside self-rising flour?
Some recipes intentionally call for extra baking powder or salt on top of self-rising flour for a bigger rise or bolder seasoning — in that case, make the substitute as directed here and then still add whatever additional baking powder or salt the recipe separately lists, since that extra amount was written expecting the self-rising flour's leavening as a baseline, not as a replacement for it.