Yeast is a type of fungus that is so tiny you need a microscope to see even one! A single drop of bread dough can have millions of yeast living in it. Even though yeast is super small, it is a giant helper in the kitchen and people have been using it for thousands and thousands of years. Yeast is actually all around us, floating in the air and sitting on the skin of fruits like grapes and apples. There are over 1,500 different kinds of yeast in the world, but the one we use for baking is called baker’s yeast.
When you mix yeast into bread dough, something magical happens. The yeast starts eating the sugar in the dough, and as it munches away, it burps out tiny bubbles of a gas called carbon dioxide! Those little bubbles get trapped inside the dough and make it puff up bigger and bigger. That is why bread dough rises and gets so soft and fluffy when it bakes. Without yeast, our bread would be flat and hard like a cracker. Yeast also helps make other yummy foods like pizza dough, cinnamon rolls, and soft pretzels, so it is one of the most important tiny helpers in the whole world!
