Pro Tip: The three types of leavening can help create innovative bakery products.

Leavening is an essential part of baking. It refers to the rising action that aerates doughs or batters during the mixing and baking process. Through leavening, the finished products are greater in volume than the raw ingredients and more flavorful with edible characteristics.

There are three main types of leavening: biological, chemical and mechanical.

Mechanical and steam leavening

Mechanical incorporation of air is one method of leavening. In the mechanical method, there is no production of carbon dioxide and is achieved by air entrapped during the mixing process.

This process is used in the manufacturing of angel food, sponge and pound cakes. In angel food cakes, genoise and layer cake batters, air is trapped in the eggs during the whipping process. For traditional pound cakes, the mechanical method of leavening is the creaming of the shortening and sugar.

Steam is another powerful type of physical leavening. Certain ingredients such as butter, eggs and milk contain water that will evaporate in the oven, creating steam. Water present in the ingredients evaporate in the oven turning to steam, which, in turn, causes the dough to puff up. This phenomenon is seen in cream puffs and laminated dough such as croissants, Danish and puff pastry.

Biological leavening agent: Yeast

Yeast is a type of biological leavening, as it is a living organism. Yeast consumes sugars and starches present in dough and produces carbon dioxide and alcohol. This fermentation process is what makes yeast dough rise. Most bakers utilize yeast (saccharomyces cerevisiae) in the form as fresh yeast, dry instant yeast or active dry yeast. To form sourdoughs, bakers incorporate wild yeast.

Yeast in the presence of warmth and moisture converts its food (sugar and starch) into carbon dioxide and alcohol through fermentation. Through this carbon deoxidation, it gives rise to the baked product.

Chemical leavening agent: Baking powder and baking soda

Baking soda and baking powder are common forms of chemical leavening used in bakeries for cakes, batters, cookies and biscuits. When combined with water, the sodium bicarbonate and acid salts react to produce gaseous carbon dioxide, thereby giving volume.

Baking soda or sodium bicarbonate must be used in a recipe that contains an acidic ingredient in order to be effective. Common baking ingredients that include an acidic component include buttermilk, brown sugar, chocolate, molasses, lemon juice and natural cocoa powder (Dutch processed cocoa powder is not acidic).

Baking powder contains baking soda combined with an acid, which means that when baking powder is hydrated it will immediately begin reacting because the acidic component is already present. Most commercial baking powders are dual-acting, meaning they contain two leavening acids (one slow and one fast) in order to control the rate of reaction.

These different leavening systems can also be used together to create new innovative products for your bakery.

Richard Charpentier is a classically trained French baker, CMB, holds a degree in baking science from Kansas State University, and is owner and chief executive officer of Baking Innovation. Connect with him on LinkedIn.