What is the main purpose of yeast in baking?

• A. To sweeten the dough
• B. To add flavor to bread
• C. To cause dough to rise by producing carbon dioxide
• D. To prevent spoilage of the dough

Answer: (C)

The main purpose of yeast in baking is to cause dough to rise by producing carbon dioxide. When yeast ferments, it converts sugars present in the dough into alcohol and gases, predominantly carbon dioxide. This gas gets trapped within the dough's structure, causing it to expand and rise. This leavening process is essential, as it creates the light and airy texture that is characteristic of many baked goods such as bread, rolls, and pastries.

Understanding this function of yeast is crucial, as it directly relates to the science behind baking; without the carbon dioxide produced by yeast, bread would remain dense and flat, lacking the desired volume and crumb structure. While yeast can impart a certain flavor and aroma to the bread, its primary role is indeed focused on leavening through gas production.