What is yeast

What is yeast

Yeast really is, in fact, a living organism. It is a member of the fungus family. While there are about 500 species of yeast, Saccharomyces cerevisiae, commonly known as baker's yeast, is the one most often used in the kitchen. Yeast is tiny: just one gram holds about 25 billion cells.

Yeast is a single celled microscopic organism, ranging in size 3 – 8um. Cells of the baker’s yeast strain are typically oval in shape. A thin cell wall and inner membrane enclose the inner cytoplasm, where the nucleus, vacuoles, and cellular material are contained. The semi-permeable cell wall permits the passage of carbohydrates and other nutrients into the cell, while metabolic by-products such as alcohol and carbon dioxide are released.

The purpose of yeast in baking is to make bread rise. Yeast does this by feeding on the sugars and releasing carbon dioxide in the process. Yeast is also responsible for the wonderful aroma and flavour and naturally makes bread more nutritious.