yeast

Any of various unicellular fungi of the genus Saccharomyces, especially S. cerevisiae, reproducing asexually by budding or sexually through the production of ascospores and capable of fermenting carbohydrates.

Any of numerous fungi that exhibit a one-celled growth form and reproduce by budding, including certain candidas that can cause infections in humans.

Froth consisting of yeast cells together with the carbon dioxide they produce in the process of fermentation, present in or added to fruit juices and other substances in the production of alcoholic beverages.

A powdered or compressed commercial preparation of yeast cells, used chiefly as a leavening agent or as a dietary supplement.

An agent of ferment or activity.

To ferment.

A yellowish substance, having an acid reaction, produced during the alcoholic fermentation of saccharine fluids, rising partly to the surface in the form of a frothy, flocculent, viscid matter (top or surface yeast), and partly falling to the bottom (bottom or sediment yeast).

Spumc or foam of water; froth.

The foam, or troth (top yeast), or the sediment (bottom yeast), of beer or other in fermentation, which contains the yeast plant or its spores, and under certain conditions produces fermentation in saccharine or farinaceous substances; a preparation used for raising dough for bread or cakes, and making it light and puffy; barm; ferment.