What is the role of yeast in bread-making?

The role of yeast in bread-making primarily involves the production of carbon dioxide through fermentation. When yeast, a type of fungus, consumes sugars present in the dough, it metabolizes them and releases carbon dioxide gas as a byproduct. This gas gets trapped in the dough's structure, creating air pockets that cause the bread to rise and achieve its light and airy texture.

While yeast may contribute a certain flavor profile to the bread and it can influence the color of the crust indirectly by interacting with sugars during baking, its primary and most crucial function is the leavening action facilitated by carbon dioxide production. This process is essential for achieving the desired volume and texture in bread, making it a foundational element in bread-making.