Here’s where it gets interesting. The baking powder in self-rising flour is usually a double-acting kind. That means it releases gas twice—once when it gets wet, and again when it hits the oven heat.
Self Rising Flour All Purpose Flour Conversion | Detroit Chinatown
This is why your self-rising biscuits get that beautiful, crackly top and fluffy inside. It’s a tiny, delicious science experiment happening in your kitchen. How neat is that?
But because that baking powder is already mixed in, self-rising flour has a shorter shelf life. After about six months, the chemical reaction can weaken. Freshness matters here.
