Which cooking technique involves incorporating air into a mixture?

The correct answer involves aeration, which is a critical cooking technique that introduces air into a mixture. This process is essential for various dishes, especially baked goods, as it helps create a light and fluffy texture. By incorporating air, aeration enhances the volume and improves the overall structure of mixtures like batters and doughs.

Aeration can be achieved through several methods, including whisking, beating, or folding ingredients, which effectively traps air bubbles within the mixture. This trapped air expands during baking, resulting in a desirable rise and airy texture, which is particularly important for cakes, soufflés, and meringues.

While the other options—fermentation, emulsification, and whipping—each play important roles in cooking and food preparation, they do not specifically focus on incorporating air in the same manner. Fermentation involves the conversion of sugars to alcohol and carbon dioxide by yeast or bacteria, emulsification is about combining liquids that typically do not mix (like oil and water), and whipping is actually a method that contributes to aeration through vigorous mixing, but its primary focus is more about the action rather than the concept of aeration itself. Thus, aeration is the most directly relevant technique related to the process of incorporating air into mixtures.