How Bread Rises

Have you ever wondered how bread goes from a flat lump of dough to a big, fluffy loaf? The secret is yeast, a tiny living organism that you cannot see without a microscope. When yeast eats sugar in the dough, it makes carbon dioxide gas. Those tiny gas bubbles get trapped in the dough and make it puff up and rise.

What Is Yeast?

Yeast is a tiny, single-celled fungus. It is so small that millions of yeast cells fit in one teaspoon. When yeast is mixed with warm water and flour, it wakes up and starts eating the sugars in the flour. As it eats, it produces carbon dioxide gas and alcohol. The gas makes bubbles in the dough, and the alcohol evaporates when the bread bakes.

The Rising Process

After mixing the dough, bakers let it sit in a warm place. This is called proofing. The warm temperature helps the yeast work faster. The dough slowly gets bigger as more gas bubbles form inside it. Most breads need to rise at least once before baking. Some breads rise two or three times for an even fluffier texture.

Fun Facts

• Yeast has been used to make bread rise for over 5,000 years.
• Baking soda and baking powder can also make bread rise, but they work differently than yeast.
• Sourdough bread uses wild yeast from the air instead of store-bought yeast.

Did You Know?

Ancient Egyptians were some of the first people to discover that yeast could make bread rise, probably by accident!