Etymology : Middle English yest, from Old English gist; akin to Old High German jesen, gesen to ferment, Greek zein to boil
Pronunciation : 'yEst,
esp Southern & M
Function : noun
Date : before 12th century
1. leavening agent (used in bread and beer). yeast\yeast\ , n. [oe. &yogh;eest, &yogh;est, as. gist; akin to d. gest, gist, g. gischt, g?scht, ohg. jesan, jerian, to ferment, g. gischen, g?schen, g?hren, gr. boiled, zei^n to boil, skr. yas. ?111.].
2. 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.
3. spume, or foam, of water. they melt thy yeast of waves, which mar alike the armada's pride, or spoils of trafalgar.yeast cake, a mealy cake impregnated with the live germs of the yeast plant, and used as a conveniently transportable substitute for yeast.yeast plant (bot.), the vegetable organism, or fungus, of which beer yeast consists. the yeast plant is composed of simple cells, or granules, about one three-thousandth of an inch in diameter, often united into filaments which reproduce by budding, and under certain circumstances by the formation of spores. the name is extended to other ferments of the same genus. see:
saccharomyces.yeast powder, a baling powder, -- used instead of yeast in leavening bread.yeast n.
4. a commercial leavening agent containing yeast cells; used to raise the dough in making bread and for fermenting beer or whiskey [syn: barm].
5. any of various single-celled fungi that reproduce asexually by budding or division.
6. The foam, or troth , or the sediment , 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.
7. Spume, or foam, of water. any of various single-celled fungi that reproduce asexually by budding or division a commercial leavening agent containing yeast cells; used to raise the dough in making bread and for fermenting beer or whiskey.
8. Yeast is a kind of fungus which is used to make bread rise, and in making alcoholic drinks such as beer. a type of fungus used for producing alcohol in beer and wine, and for making bread rise. Any of certain economically important and usually single-celled fungi (see:
fungus), most of which are classified as ascomycetes. Found worldwide in soils and on plant surfaces, yeasts are especially abundant in sugary mediums such as flower nectar and fruits. The types commonly used in the production of bread, beer, and wine are selected strains of Saccharomyces cerevisiae; the small cakes and packets used contain billions of individual yeast cells, each of which can ferment approximately its own weight of glucose per hour. Dried yeast is 50% protein and is rich in B vitamins; brewer's yeast is sometimes taken as a vitamin supplement. Some yeasts are mild to dangerous pathogens of humans and other animals. Candida albicans, for example, irritates oral and vaginal linings, and Histoplasma and Blastomyces cause persistent lung infections.