Why is yeast added to some breads and cheese?

Yeast is added to some breads and cheeses for a variety of reasons. Yeast is a type of fungus that is responsible for the process of fermentation, which converts sugar into alcohol and carbon dioxide. In breads, yeast is responsible for the rising, giving it a light and fluffy texture. In cheeses, yeast is used to produce flavor compounds and to help ripen the cheese.

In bread, yeast consumes the sugar in the flour and produces carbon dioxide gas as a byproduct. This gas causes the dough to rise, giving bread its characteristic light and airy texture. Yeast also produces ethanol and other flavor compounds that contribute to the taste and aroma of bread. Some types of bread, such as sourdough, rely on yeast for their characteristic sour flavor.

In cheese, yeast is used to produce flavor compounds and to help ripen the cheese. Different strains of yeast produce different flavor profiles, and some cheeses, such as brie and camembert, are known for their distinctive yeast-driven flavors. Yeast also produces enzymes that help break down the proteins and fats in cheese, which contributes to the cheese's texture and flavor.

Yeast is a versatile microorganism that plays a vital role in the production of many fermented foods. Its ability to produce carbon dioxide, ethanol, and other flavor compounds makes it an important ingredient in bread, cheese, and a variety of other foods.