For thousands of years, bakers have been using the single-celled organism yeast to create the soft and chewy food staple bread. Yeast not only helps bread dough rise, but it also aids in developing and strengthening proteins in the dough and adds to its flavor.
Yeast may be best known as the agent in bread that makes it rise. When you add yeast to your flour and water mixture, it breaks down the large starch molecules into simple sugars. During this process, the yeast creates carbon dioxide and ethyl alcohol, which make the air bubbles that causes the bread dough to grow.
To grow yeast and get your bread to rise, it needs to be at the right temperature, which is 77 to 86 degrees Fahrenheit, according to a 2012 article published in the Pakistan Journal of Food Science.
When it comes to bread baking, gluten is an important element. It helps strengthen the bread dough so it can hold more gas created by the yeast, says Fine Cooking. The more you knead the dough, the more gluten you form. Yeasts assists in the kneading, or mixing process, by creating the bubbles, which allows for more proteins to connect to make more gluten.
Yeast fermentation not only adds air bubbles, but also flavor as it breaks down the tasteless, large starchy molecules into the smaller sweet sugars. The creating of the ethyl alcohol also adds to the flavor of the bread. Additionally, as the fermentation process continues, the yeast also adds an acidic element to the bread.