Organic Leavening

Yeast is used to produce carbon dioxide, which, in turn, causes the dough to rise. There are many types of yeast, but the most commonly used for leavening in baking (and brewing) is that known as Saccharomyces cerevisiae. Yeast requires food, moisture, oxygen, and a warm environment, and dough provides the best of all possible worlds for these organisms to thrive.