Yeast is a single-celled fungi used to leaven bread. To grow, yeast digests its favorite food, sugar, in its various forms, granulated or brown sugar (sucrose); honey, molasses, maple syrup, fruit (fructose and glucose); and maltose in flour. As the yeast digests the sugar, it ferments to produce carbon dioxide (gas) and ethyl alcohol. The gas is trapped in the stretchy dough network and expands. The ethyl alcohol gives flavor and aroma to the bread.
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