Why is yeast used in the baking industry?

Yeast, particularly Saccharomyces cerevisiae (baker's yeast), is essential in baking because it produces carbon dioxide gas through fermentation, which makes dough rise and creates the light, fluffy texture we enjoy in bread, cakes, and pastries. When yeast is mixed with flour, water, and sugar, it ferments the sugars, releasing CO₂ bubbles that get trapped in the dough's gluten network, causing it to expand. This process also produces small amounts of alcohol, which evaporates during baking, and contributes to the bread's flavor and aroma. The rising process improves the texture, volume, and digestibility of baked goods. Yeast also produces enzymes and organic compounds that enhance flavor complexity. Bakers control fermentation by adjusting temperature, time, and ingredient ratios. Without yeast, bread would be dense, flat, and less palatable.