\ 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 Fluconazole inhibits the growth of yeast by decreasing the production of ergosterol. Joshua Cohen, Forbes, 7 June 2021 Camellia yeast extract, an ingredient that was specially created for Chanel, boosts skin’s natural hyaluronic acid production. Celia Shatzman, Forbes, 29 May 2021 In the finished beer, Kolsch yeast accentuates the fruity flavors of the fruit as well as the hops, leaving drinkers with a light-bodied but fruit-forward brew., 25 May 2021 Brews like hefeweizens need yeast for their signature haze. Claire Porter, Popular Mechanics, 25 May 2021 The live cultures of the yeast convert sugar into alcohol and then the brew is infused with real fruits or natural or artificial flavors. Kathy Stephenson, The Salt Lake Tribune, 25 May 2021 Sitting behind his sushi counter is a special bottle of Ken Hirata’s Hawaiian shochu, an exclusive small batch of the Japanese liquor made using cacao yeast. WSJ, 25 May 2021 Dad will have the best time experimenting with all things yeast—thanks to this home brewing kit. Rachel Dube, USA TODAY, 21 May 2021 Introduced into the body by a cut or scratch, this fungus transforms into a budding form resembling a yeast. Maryn Mckenna, Scientific American, 19 May 2021 Recent Examples on the Web: Verb Another issue is that the drug is not suitable for one group of people particularly prone to yeast infections: pregnant people. Carolyn L. Todd, SELF, 3 June 2021 But the operation still feels kind of smalltown, punctuated by the fact that a Yuengling family member followed the recipes and yeast down to Texas to begin a historic expansion for the company. Sarah Blaskovich, Dallas News, 11 May 2021 Supply shortages have made flour, beans, pasta, and yeast hot commodities. Amanda Mull, The Atlantic, 5 Mar. 2021 Witness the disappearing flour and yeast off grocery store shelves, the uptick in sourdough. Washington Post, 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, 28 Apr. 2020 Focaccia is a flat, yeasted Italian bread similar in taste and texture to pizza dough. Katlyn Moncada, Better Homes & Gardens, 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, 4 Feb. 2020 Same for dozens of styles of fish stew, yeasted rolls, cakes, and pies found around the world. National Geographic, 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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Last Updated

14 Jun 2021

Cite this Entry

“Yeast.” Dictionary, Merriam-Webster, Accessed 19 Jun. 2021.

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More Definitions for yeast



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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