\ 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 yeastlike (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 Remember the rule and the reason: put shallow containers with beer or yeast water right outside gardens and containers so as not to attract slugs and snails into the garden. Jeff Lowenfels, Anchorage Daily News, "Think rabbits are plaguing your garden? You’re off by a hare.," 18 June 2020 Plain yogurt fared better (B+), with kefir, milk fermented with bacteria and yeast, the runaway winner (A+). Becky Krystal, Washington Post, "The proof is in the pancakes: Adding lemon juice or vinegar to milk is a bad buttermilk substitute," 15 June 2020 Hands-on giving Flour and yeast have been tough to find, as a baking trend took off amid stay-at-home orders. Whitney Eulich, The Christian Science Monitor, "Eat well, do good: Bread for the People makes giving back delicious," 12 June 2020 Outages of ingredients such as yeast has proved to be motivational and inspired them to experiment and find innovative culinary solutions. Masada Siegel, CNN, "Pandemic blues: Crush it with creativity," 12 June 2020 Warm and soft and sweet, made with flour and oil and eggs and honey and, unlike sourdough: yeast. Rachel Levin,, "Challah giving sourdough some competition during coronavirus," 11 June 2020 The sourdough bread-making boom has caused yeast and flour sales to, um, rise. Jenni Avins, Quartz, "The “hipsteader” and other new consumer species in the age of coronavirus," 6 June 2020 Notable examples include multiple different species of yeast hybrids that cause the human diseases cryptococcosis and candidiasis. Antonis Rokas, The Conversation, "A new hybrid fungus is found in hospitals and linked to lung disease," 4 June 2020 At Urban Donut in Uptown Dallas, DYO-doughnutters start with a red velvet doughnut, blueberry cake, yeast, long john or others. Sarah Blaskovich, Dallas News, "8 delicious doughnut shops in Dallas-Fort Worth on National Donut Day, June 5," 4 June 2020 Recent Examples on the Web: Verb 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

Time Traveler

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

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Statistics for yeast

Last Updated

25 Jun 2020

Cite this Entry

“Yeast.” Dictionary, Merriam-Webster, Accessed 7 Jul. 2020.

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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 yeastlike (audio) \ adjective

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More from Merriam-Webster on yeast

Thesaurus: All synonyms and antonyms for yeast

Rhyming Dictionary: Words that rhyme with yeast

Spanish Central: Translation of yeast

Nglish: Translation of yeast for Spanish Speakers

Britannica English: Translation of yeast for Arabic Speakers Encyclopedia article about yeast

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