Yeast is used in making bread …

This is the reasonCarbon dioxide is what gives alcoholic beverages such as beer and champagne their characteristic bubbles and is also responsible for rising bread. As yeast begins to metabolize sugars in bread dough, the carbon dioxide gas is trapped within the gluten strands, creating bubbles and causing a leavening action. In beverages, the carbon dioxide is trapped within the liquid by the pressure of the sealed container. When the container is opened, the pressure is released and the carbon dioxide begins to release via a bubble. Alcohol, the other byproduct of yeast fermentation, is also produced during the bread making process but evaporates as the bread bakes. When making alcoholic beverages, yeast is allowed to ferment for a much longer period of time, causing it to produce more alcohol.