Self-raising flour

Self-raising flour is soft wheat flour with a raising agent, usually baking powder, already mixed through it, so cakes, scones and pancakes rise without anything else added. In the US it is called self-rising flour.

The two are not quite the same. American self-rising flour must be seasoned with salt as well as leavened (21 CFR 137.180), so when a US recipe uses it, the recipe usually adds little or no salt. If you swap in UK self-raising flour, add a pinch of salt with the flour.

Raising agents lose strength over time, so an old bag can give flat, heavy results. Check the best-before date before a bake that matters.

If you only have plain flour, you can mix baking powder into it. Packets of baking powder and many recipes give a ratio; follow theirs, because too much leaves a bitter, soapy taste. Sift or whisk the two together well so the cake rises evenly.

Self-raising flour is not suitable for bread made with yeast.