Leavening Agents and Baked Goods: Types of Raising Agents

Leavening agents are ingredients and techniques used in baking and cooking to produce light and airy foods. These methods, including yeast, baking powder, baking soda, and physical processes like whipping and creaming, work by releasing gases into a batter, dough, or standalone ingredient. The gases create pockets of air bubbles in the food, which can cause it to expand (or rise) and achieve a lighter texture.

Also referred to as leaveners and raising agents, leavening agents can be naturally occurring or chemically produced, and introduced as a supplemental ingredient or via a mechanical process. If you’re an avid baker or home cook, you’ve probably used some or all of these methods, maybe even in the same recipe.

Chemical leavening agents use chemical reactions to release gas into baked goods. If you’ve ever made a volcano out of baking soda and vinegar, you understand the basic principle behind chemical leavening: When an acid (such as vinegar, lemon juice, or cream of tartar) mixes with a base (such as baking soda or baking powder), the result is an explosion. Or, when it comes to baking, the reaction produces a controlled amount of bubbles that cause baked goods to rise. Chemical leavening agents are primarily used in cakes and quick breads.

1. 1. Baking soda: Baking soda, also known as sodium bicarbonate or bicarbonate of soda, is a salt containing hydrogen, sodium, carbon, and oxygen. When mixed with an acidic ingredient (like vinegar, lemon juice, yogurt, or buttermilk), it releases bubbles of carbon dioxide gas, which makes baked goods expand. Baking soda is used to produce baked goods like light, fluffy pancakes and irish soda bread.
2. 2. Cream of tartar: Potassium bitartrate, commonly known as cream of tartar, is a powdery substance left behind in barrels after the wine fermentation process. Cream of tartar is mostly acidic in makeup, which means it can act as a leavener in the presence of a base like baking soda. It can also act as a stabilizer, helping the bubbles in whipped egg whites maintain their shape when making meringue.
3. 3. Baking powder: Baking powder is an ingredient that combines baking soda with cream of tartar to create a one-stop-shop chemical leavener that doesn’t require an additional acid to activate. There are two types of baking powder. The more common double-acting powder works in two phases: first, when it’s introduced to wet ingredients, and next, when it’s exposed to heat over 170 degrees Fahrenheit. Single-acting baking powder is activated by heat alone.

Unlike chemical leavening agents, which are manufactured, biological leavening agents consist of naturally occurring microorganisms which facilitate the fermentation process during baking. Biological leavening agents, the most famous of which is yeast, are commonly used in the bread making process. During fermentation, biological leavening agents break down the sugars in bread dough and produce carbon dioxide gas and flavor compounds to lift and flavor your baked goods.

1. 1. Active dry yeast: Active dry yeast is probably the most common biological leavening agent used in baking. Typically sold in individually portioned packets, this yeast must be “activated” in warm water before being added to baked goods. Activation ensures that the dried yeast is still alive, since the yeast granules can die during the drying process or if the yeast has been sitting around for a while.
2. 2. Instant dry yeast: Instant yeast is distinguished from active dry yeast in that it doesn’t require any proofing and can be added as-is to a dough recipe. Instant yeast is sometimes sold as bread machine yeast and undergoes a gentler drying process which kills less of the yeast.
3. 3. Fresh yeast: Also known as cake yeast or baker’s yeast, fresh yeast is most commonly used in commercial bakeries, since it dies after a few days. Fresh yeast is sold in larger one-pound vacuum-packed portions, and can be dissolved before use or added directly to dough.
4. 4. Sourdough starter: Most commonly used in the production of sourdough bread, a starter is a piece of dough containing wild yeasts and lactobacillus bacteria. Sourdough starters can be incorporated into a bread dough for a slow, natural leavening effect in breads.

Mechanical leavening is a more labor-intensive variety of leavening, in which a baker forces air into a batter or dough by rapidly mixing or agitating the ingredients. This type of aeration typically requires plenty of arm strength (or specialized machinery) and occurs primarily through two common processes to create delicate desserts and garnishes like whipped cream, sponge cake, and meringue. Physical leavening is a naturally occurring process that happens when baked products are heated.

1. 1. Whisking: When you vigorously whisk or whip ingredients like egg whites or cream, the mechanical action creates a foaming effect. This is the result of rapidly introducing air into an ingredient stable enough to maintain those air bubbles.
2. 2. Creaming: Creaming is a type of mechanical leavening that occurs when you rapidly beat a solid fat (like butter) together with sugar or other ingredients, allowing air pockets to form throughout the mixture and build on the volume of the ingredients.
3. 3. Steam: This form of physical leavening occurs in all baked goods during the cooking process. When baked goods enter the oven, water evaporates from the dough or batter, changing from a liquid to gaseous state, lifting the baked goods in the process. This is how puff pastry can expand without the use of chemical or biological leaveners—the water in the dough is distributed so that it creates air pockets during baking.

Becoming a great baker involves effectively using each of these types of leavening agents to create the best possible texture in your baked goods.

1. 1. Don’t go overboard with chemical leaveners. While it can be tempting to add more chemical leavener than called for in a recipe in order to produce super-airy baked goods, overusing these sensitive leaveners can have the opposite effect. Using too much baking soda or baking powder in a recipe can result in your baked goods collapsing.
2. 2. Play around with acids. Always pair baking soda with an acidic ingredient. Experiment with different fermented additions, like ginger beer, wine, sour cream, Greek yogurt, and more, to create a leavening effect in your dishes.
3. 3. Appliances can be your friend. Mechanical leavening by hand can be an arduous process, resulting in arm pain and exhaustion. For the most pain-free method of mechanical leavening, use a hand mixer or stand mixer to introduce plenty of air into a dish without breaking a sweat.

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