Yeast

The microbes that give us bread, beer, and more!

Budding yeast under a microscope (colorized)

Yeast are single-cell eukaryotic organisms (meaning they have a nucleus). The yeast most commonly used in the kitchen is Saccharomyces cervisiae, or Baker's yeast. Yeast consume sugars in an anaerobic manner to produce ethanol and carbon dioxide, a process known as fermentation.

In bread, the carbon dioxide produces by fermentation leavens the bread. Yeast reproduce asexually through a process called budding.