fermentation

American  

[fur-men-tey-shuhn] / ˌfɜr mɛnˈteɪ ʃən /

noun

1. the act or process of fermenting.

2. a change brought about by a ferment, as yeast enzymes, which convert grape sugar into ethyl alcohol.

3. agitation; excitement.

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fermentation British  

/ ˌfɜːmɛnˈteɪʃən /

noun

1. Also called: ferment.  a chemical reaction in which a ferment causes an organic molecule to split into simpler substances, esp the anaerobic conversion of sugar to ethyl alcohol by yeast

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fermentation Scientific  

/ fûr′mĕn-tā′shən /

1. The process by which complex organic compounds, such as glucose, are broken down by the action of enzymes into simpler compounds without the use of oxygen. Fermentation results in the production of energy in the form of two ATP molecules, and produces less energy than the aerobic process of cellular respiration. The other end products of fermentation differ depending on the organism. In many bacteria, fungi, protists, and animals cells (notably muscle cells in the body), fermentation produces lactic acid and lactate, carbon dioxide, and water. In yeast and most plant cells, fermentation produces ethyl alcohol, carbon dioxide, and water.

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fermentation Cultural  

1. A chemical reaction in which sugars are broken down into smaller molecules that can be used in living systems. Alcoholic beverages, such as beer, wine, and whiskey, are made from the controlled use of fermentation. Fermentation is an anaerobic process.

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Other Word Forms

• fermentative
  adjective
• fermentatively
  adverb
• fermentativeness
  noun
• nonfermentation
  noun
• prefermentation
  noun
• self-fermentation
  noun

Etymology

Origin of fermentation

First recorded in 1350–1400; Middle English fermentacioun, from Late Latin fermentātiōn-, stem of fermentātiō, from Latin fermentāt(us) “fermented” (past participle of fermentāre “to ferment”; see ferment) + -iō -ion

Explanation

Fermentation is the process in which a substance breaks down into a simpler substance. Microorganisms like yeast and bacteria usually play a role in the fermentation process, creating beer, wine, bread, kimchi, yogurt and other foods. Fermentation comes from the Latin word fermentare, meaning “to leaven.” To make bread rise, you use a leavening agent to “wake up” dry yeast by mixing it with water. The yeast then starts “eating” the sugar in the dough and off-gassing alcohol: that’s fermentation. Grape juice becomes wine as the fermentation process is complete.

Example Sentences

These enzymes become active as the dough grows more acidic during fermentation.

From Science Daily • Mar. 16, 2026

"The Human Flatus Atlas will establish objective baselines for gut microbial fermentation, which is essential groundwork for evaluating how dietary, probiotic or prebiotic interventions change microbiome activity."

From Science Daily • Mar. 14, 2026

Employees peeked through a wrought-iron gate as former Noma head of fermentation Jason Ignacio White read a letter decrying Redzepi.

From Los Angeles Times • Mar. 13, 2026

She points to the increase in accessibility of at-home fermentation, fermentation programs at culinary school and cabbage varieties available at the local farmer’s markets in New York City.

From Salon • Feb. 21, 2026

The rumen is like a twenty-five-gallon fermentation tank.

From "The Omnivore's Dilemma" by Michael Pollan