Two leavening agents are used in baking: yeast and baking powder. Yeast may be fresh or dried (powdered). It is added to dough such as brioche, bread, and croissant, to make the dough rise. It is important to note that yeast becomes liquid when mixed directly with salt or sugar, and thus looses its effectiveness.
Baking powder gives dough a crumbly texture and adds to the lightness of the genoese sponge cake. Self-rising flour has been premixed with baking powder and is good for use in pastries and cakes.
