How does yeast make bread rise and beer ferment?

Yeast is like tiny bubbles inside bread and beer that help them get big and bubbly.

Yeast is a teeny, tiny living creature, so small you can’t see it with your eyes, but it has a job: making things grow and bubble up.

When you mix flour, water, and yeast together in dough, the yeast starts to eat the sugar in the flour. As it eats, it produces carbon dioxide gas, which is like invisible bubbles. These bubbles get trapped inside the dough, making it swell up, just like when you blow up a balloon! When you bake the bread, the heat makes those bubbles stay big and fluffy, giving the bread its soft, risen shape.

In beer, yeast also eats sugar, but instead of being in dough, it's in liquid. As the yeast eats, it still produces carbon dioxide gas, which gives beer its fizzy bubbles. But it also makes alcohol, turning sweet liquid into something bubbly and tasty to drink.

So whether you're eating bread or drinking beer, yeast is working hard behind the scenes, like a tiny bubble chef!