yeast

1 of 2

noun

ˈyēst 

 especially Southern and Midland US  ˈēst

1

a

: 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

yeast-like adjective

or less commonly yeastlike

ˈyēst-ˌlīk 

 especially Southern and Midland US  ˈēst-

yeast

2 of 2

verb

yeasted; yeasting; yeasts

intransitive verb

: ferment, froth

Synonyms

Noun

• boost
• encouragement
• goad
• impetus
• impulse
• incentive
• incitation
• incitement
• instigation
• momentum
• motivation
• provocation
• spur
• stimulant
• stimulus

Examples of yeast in a Sentence

Noun

taxation without representation proved to be the yeast of rebellion

Recent Examples on the Web

Noun

These shampoos contain active ingredients that specifically target the yeast, helping to eradicate it from your dog's body. —Amber Smith, Discover Magazine, 3 Apr. 2024

Dandruff, also known as seborrheic dermatitis, is caused by the overgrowth of malassezia, a yeast that lives on the scalp, according to Mayo Clinic. —Caroline C. Boyle, USA TODAY, 31 Mar. 2024

The findings of one study, published last fall, suggest that the last common ancestor of yeast and humans — the first eukaryote, or cell bearing a nucleus and mitochondria — already had the tools necessary to end itself some 2 billion years ago. —Quanta Magazine, 6 Mar. 2024

Sugar helps ferment yeast and contributes to flavor, color and a tender crust. —Rita Nader Heikenfeld, The Enquirer, 17 Feb. 2024

Fermented Foods & Beverages The process of fermentation involves the break down of carbohydrates, including sugar and starch by bacteria and yeast to produce acids or alcohol. —Daphne Ewing-Chow, Forbes, 14 Feb. 2024

When made properly, yeast grown on rice produces various compounds, including lovastatin, which is known to lower cholesterol, the physician said. —Kate Gibson, CBS News, 29 Mar. 2024

In 2022, for example, one of the Colorado Marijuana Enforcement Division’s recalls were aimed at products wrapped in palm leaves and featuring corn husk filters, noting that the total yeast and mold levels found in the products were unsafe. —Harrison Bard, Rolling Stone, 1 Mar. 2024

That’s the scoby, Bledsoe explained — a bacteria and yeast culture to help ferment the black and green tea. —Jenna Thompson, Kansas City Star, 27 Feb. 2024

Verb

Making wine is as simple as crushing the grapes and waiting—the juice is so high in sugar that yeasts on the skin will ferment the juice, creating alcohol. —Alex Mayyasi, Smithsonian Magazine, 28 Nov. 2023

Make dough: Add eggs, shortening, sugar, salt, 2 cups of the flour, and remaining 1 cup warm water to yeast mixture. —Southern Living Test Kitchen, Southern Living, 15 Oct. 2023

Add shortening mixture to yeast mixture along with 4 cups bread flour. —Micah A Leal, Southern Living, 20 July 2023

To create tiny morphine factories, scientists added to yeast genetic components from poppy, sugar beets, and a soil bacterium. —Carl Engelking, Discover Magazine, 20 May 2015

Spring Valley Apple Cider Vinegar Capsules are preservative-free, artificial coloring and flavoring-free, and also yeast, wheat, milk, lactose, and sugar-free. —Amber Smith, Discover Magazine, 14 Oct. 2022

Lichens are symbiotic organisms of fungi, algae and possibly yeast that live off each other, not your tree. —Jessica Damiano, Chicago Tribune, 17 Jan. 2023

Some dogs, on the other hand, are allergic to yeast. —Amber Smith, Discover Magazine, 18 Oct. 2022

Here, the liquid becomes wine thanks to yeast that transforms the grape juice into alcohol and carbon dioxide. —Karla Walsh, Better Homes & Gardens, 29 Aug. 2022

Word History

Etymology

Noun

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

First Known Use

Noun

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

Verb

1819, in the meaning defined above

Phrases Containing yeast

• yeast infection
• nutritional yeast
• baker's yeast
• brewer's yeast

Kids Definition

yeast

noun

ˈyēst,

ˈēst

1

a

: a one-celled fungus that produces alcohol during the process of fermentation

also : any of various similar fungi

b

: a yellowish foamy material that may occur on the surface of sweet liquids (as fruit juices) undergoing fermentation and that consists chiefly of yeast cells and carbon dioxide

c

: a commercial product containing living yeast cells that is used mostly in the making of alcoholic beverages and as a leaven especially in baking bread

2

: something that causes motion or activity

yeasty

ˈyē-stē

ˈē-stē

adjective

Medical Definition

yeast

noun

ˈyēst 

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

yeastlike

-ˌlīk 

adjective