\ ˈyēst How to pronounce yeast (audio) , especially Southern and Midland US ˈēst \

Definition of yeast

 (Entry 1 of 2)

1a : a yellowish surface froth or sediment that occurs especially in saccharine liquids (such as fruit juices) in which it promotes alcoholic fermentation, consists largely of cells of a fungus (such as the saccharomyces, Saccharomyces cerevisiae), and is used especially in the making of alcoholic liquors and as a leaven in baking
b : a commercial product containing yeast fungi in a moist or dry medium
c(1) : a unicellular fungus that is present and functionally active in yeast, usually has little or no mycelium, and reproduces by budding
(2) : any of various similar fungi
2 archaic : the foam or spume of waves
3 : something that causes ferment or activity were all seething with the yeast of revolt— J. F. Dobie


yeasted; yeasting; yeasts

Definition of yeast (Entry 2 of 2)

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Other Words from yeast


yeast-like or less commonly yeastlike \ ˈyēst-​ˌlīk How to pronounce yeast (audio) , especially Southern and Midland US  ˈēst-​ \ adjective

Examples of yeast in a Sentence

Noun taxation without representation proved to be the yeast of rebellion
Recent Examples on the Web: Noun With a couple of teaspoons of instant yeast, there will be no suspense over whether the dough will rise. Washington Post, "Warm-from-the-oven sticky pecan rolls will make Christmas, or any special morning, memorable," 23 Dec. 2020 Joseph saw a lot of parallels between the two jobs, including the base material of grain and the importance of yeast. Lou Bustamante,, "Is there such a thing as a California-style whiskey? Finally, the answer is yes," 17 Dec. 2020 Often mistaken as a symptom of dry scalp, dandruff — the shedding of skin cells from the scalp at an unusually high rate — is typically coupled with excessive oil production and the presence of a yeast-like fungus. Julie Ricevuto, Allure, "The Science of Beauty: The Complete Guide to Scalp Care," 17 Dec. 2020 The heirloom recipe is yeast bread, swirled with poppy seeds, currants and walnuts. Dallas News, "Our 13 favorite baking cookbooks of 2020," 3 Dec. 2020 Even its yeast roll package has shrunk from 36 each to a dozen. John Ewoldt, Star Tribune, "Little sign of major shortages at Twin Cities grocery stores," 22 Nov. 2020 Meuer said many of his customers plan a long fermentation period for yeast bread. Jennifer Rude Klett, Milwaukee Journal Sentinel, "Not all flour is alike; here's how to work with fresh flours from whole grains," 17 Nov. 2020 Stanford graduate student Shi-An Anderson Chen and his colleagues to efficiently make tens of thousands of yeast mutants, each different by just one base. Elizabeth Pennisi, Science | AAAS, "Microbes’ mystery DNA helps defeat viruses—and has genome-editing potential," 11 Nov. 2020 In some versions, yeast is left out of the dough, which results in a more pasta-like dough that gets layered into a thinner, free-form rectangular pie, served cut into squares. Saveur Editors, Saveur, "Our Best Classic Italian Recipes for Red-Sauced, Olive-Oiled Glory," 30 May 2017 Recent Examples on the Web: Verb Witness the disappearing flour and yeast off grocery store shelves, the uptick in sourdough. Washington Post, "Warm-from-the-oven sticky pecan rolls will make Christmas, or any special morning, memorable," 23 Dec. 2020 For recipes with drier doughs and longer mix times like pasta, tortilla or yeasted doughs, add the discard directly to the other ingredients during mixing. Erin Jeanne Mcdowell, New York Times, "8 Delicious Ways to Use Your Sourdough Discard," 28 Apr. 2020 Focaccia is a flat, yeasted Italian bread similar in taste and texture to pizza dough. Katlyn Moncada, Better Homes & Gardens, "Focaccia Art Is the Prettiest (and Tastiest) Food Trend Taking Over Social Media," 15 Apr. 2020 This comes in handy when baking yeasted breads because of the strong gluten content required to make the bread rise properly. Carmen Collins, Country Living, "10 Different Flour Types to Use in Your Baking," 4 Feb. 2020 Same for dozens of styles of fish stew, yeasted rolls, cakes, and pies found around the world. National Geographic, "The Secret History of the World's Priciest Spice," 3 May 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'yeast.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of yeast


before the 12th century, in the meaning defined at sense 1a


1819, in the meaning defined above

History and Etymology for yeast


Middle English yest, from Old English gist; akin to Old High German jesen, gesen to ferment, Greek zein to boil

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Time Traveler for yeast

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The first known use of yeast was before the 12th century

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Statistics for yeast

Last Updated

9 Jan 2021

Cite this Entry

“Yeast.” Dictionary, Merriam-Webster, Accessed 16 Jan. 2021.

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More Definitions for yeast


How to pronounce yeast (audio)

English Language Learners Definition of yeast

: a type of fungus that is used in making alcoholic drinks (such as beer and wine) and in baking to help make dough rise


\ ˈyēst How to pronounce yeast (audio) \

Kids Definition of yeast

1 : a single-celled fungus that ferments sugar to produce alcohol and carbon dioxide
2 : a commercial product containing living yeast cells that is used in baking to make dough rise and in the making of alcoholic beverages (as wine)


\ ˈyēst How to pronounce yeast (audio) \

Medical Definition of yeast

1 : a unicellular chiefly ascomycetous fungus (as of the family Saccharomycetaceae) that has usually little or no mycelium, that typically reproduces asexually by budding, and that includes forms (as Saccharomyces cerevisiae) which cause alcoholic fermentation and are used especially in the making of alcoholic beverages and leavened bread
2 : a yellowish surface froth or sediment that occurs especially in sugary fermenting liquids (as fruit juices) and consists chiefly of yeast cells and carbon dioxide
3 : a commercial product containing yeast cells in a moist or dry medium

Other Words from yeast

yeastlike \ -​ˌlīk How to pronounce yeast (audio) \ adjective

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