Leavening agent
From Wikipedia, the free encyclopedia
A leavening agent (sometimes called just leavening or leaven) is a substance used in doughs and batters that causes them to rise. In the presence of moisture, heat, acidity, or other triggers the leavening agent reacts to produce gas (often carbon dioxide) that becomes trapped as bubbles within the dough. When a dough or batter is baked, it "sets" and the holes left by the gas bubbles remain. This is what gives breads, cakes, and other baked goods their soft, sponge-like textures.
Commonly used leavening agents include:
- baker's yeast
- sourdough (dough containing a symbiosis of wild yeast and various lactic or acetic acid bacteria)
- baking powder
- baking soda (a.k.a., sodium bicarbonate)
- ammonium bicarbonate (a.k.a., hartshorn)
- potassium bicarbonate (a.k.a., potash)
- potassium carbonate or (a.k.a., pearlash)
- monocalcium phosphate
- sodium acid phosphate
Steam and air can also be considered to be leavening agents, since any existing tiny pockets of air or steam in a dough or batter will expand when heated. However, if so considered, one should probably distinguish between mechanical leavening agents and chemical leavening agents, the former producing a leavening effect through mechanical action, and the latter producing a leavening effect through chemical action.
