Leavening agent

A leavening agent is an organism or substance that when added to a dough[?] of flour and water causes it to "rise" by evolving carbon dioxide or other gasses that become trapped as bubbles[?] within the dough.

Commonly used leavening agents include:

• baker's yeast
• sourdough
• yogurt
• baking powder
• steam
• air

External Links

Leavening (http://users.rcn.com/sue.interport/food/leavning.html)