What genus includes baker's yeast and many other budding yeasts?

The genus that includes baker’s yeast and many other budding yeasts is Saccharomyces.

The best-known member is Saccharomyces cerevisiae, used for bread, beer, wine, nutritional yeast, and laboratory research. Saccharomyces cells reproduce mainly by multilateral budding: a smaller daughter cell grows from the parent before separating. The genus name comes from Greek words meaning “sugar fungus.”

Saccharomyces is broader than baker’s yeast alone. Saccharomyces paradoxus is a close wild relative of S. cerevisiae, while S. bayanus has been associated with wine fermentation. Lager brewing yeasts are also linked to this group; modern taxonomy recognizes Saccharomyces pastorianus as a hybrid involving S. cerevisiae and S. eubayanus.

A common mix-up is treating “baker’s yeast” as the genus name. It is usually a strain or preparation of S. cerevisiae, whereas Saccharomyces is the genus containing that species and its relatives. Yeast’s role in fermentation was clarified scientifically in the nineteenth century: the genus was named in 1837, Pasteur demonstrated living organisms’ role in fermentation in 1876, and Emil Hansen isolated and propagated brewing yeast in 1883.