Flour that has already had some baking powder and salt added to it is known as self-rising flour. It grows there and is a mainstay in many Southern cuisines. It's generally made with a softer, lower-protein variant of all-purpose flour. What distinguishes self-raising flour from regular flour exactly? What makes the difference? Self-rising flour already contains a raising ingredient and occasionally salt. To make your baked goods rise, you must add your raising agents separately if you use plain flour.