What is the main function of baking soda in recipes?

The main function of baking soda in recipes is to act as a leavening agent when combined with an acid. When baking soda, which is sodium bicarbonate, is mixed with an acidic ingredient (such as vinegar, lemon juice, or yogurt), a chemical reaction occurs that produces carbon dioxide gas. This gas gets trapped in the batter or dough, causing it to rise and creating a light, airy texture in baked goods. This leavening process is essential for recipes like cakes and cookies, where a soft, fluffy texture is desired.

Other options do not accurately represent the primary role of baking soda. While it can impact flavor slightly, its primary function is not flavor enhancement. Baking soda is not a preservative; its role is supportive rather than preservative in nature. Additionally, it does not serve as a thickening agent for liquids, as that function is typically fulfilled by ingredients like cornstarch or flour. Thus, the correct answer emphasizes the importance of baking soda in producing the desired texture in baked goods through the leavening process.