The word leavening in the baking trade is used to describe the source of gas that makes a dough or batter expand in the presence of moisture and heat. Leavening agents are available in different forms, from yeast (the organic leavener) to chemical, mechanical, and physical leaveners. Bakers choose the appropriate type of leavening based on the product they are making.
- 5.4: Using Yeast in Baking
- Many bakers add compressed yeast directly to their dough.
- 5.5: Baking Powder
- Baking powder is a dependable, high-quality chemical leavener. To be effective, all baking powders rely on the reaction between one or more acids on sodium bicarbonate to produce carbon dioxide gas. Just as with yeast leavening, the presence of carbon dioxide gas creates air bubbles that cause the product to rise.
- 5.6: Sodium Bicarbonate
- When sodium bicarbonate (baking soda) is moistened and heated, it releases carbon dioxide gas. If it is moistened and heated in the presence of sufficient acid, it will release twice as much gas as if it is moistened and heated without the presence of an acid.
Thumbnail: Active dried yeast, a granulated form in which yeast is commercially sold. (Public Domain; Ranveig).