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a. An agent, such as an enzyme, bacterium, or fungus, that brings about fermentation.
b. Fermentation.
a. A state of agitation or of turbulent change or development.
b. An agent that precipitates or is capable of precipitating such a state; a catalyst.
v. (fər-mĕnt′) fer·ment·ed, fer·ment·ing, fer·ments
1. To undergo fermentation: cabbage that has fermented.
2. To develop in a turbulent or agitated way; seethe: an idea that was fermenting in his mind for months.
1. To cause to undergo fermentation: Yeasts ferment sugars.
2. To produce by or as if by fermentation: ferment the wine in oak barrels; hostility that was fermented by envy.
3. To make turbulent; excite or agitate: a fiery speech that fermented the crowd.

[Middle English, from Old French, from Latin fermentum; see bhreu- in Indo-European roots.]

fer·ment′a·bil′i·ty n.
fer·ment′a·ble adj.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.fermenting - a process in which an agent causes an organic substance to break down into simpler substancesfermenting - a process in which an agent causes an organic substance to break down into simpler substances; especially, the anaerobic breakdown of sugar into alcohol
bottom fermentation - a slow kind of alcoholic fermentation at a temperature low enough that the yeast cells can sink to the bottom of the fermenting liquid; used in the production of lager
chemical action, chemical change, chemical process - (chemistry) any process determined by the atomic and molecular composition and structure of the substances involved
top fermentation - a violent kind of alcoholic fermentation at a temperature high enough to carry the yeast cells to the top of the fermenting liquid; used in the production of ale; "top fermentation uses a yeast that ferments at higher temperatures than that used for bottom fermentation"
vinification - the process whereby fermentation changes grape juice into wine
References in classic literature ?
Romanticism, which has helped to fill some dull blanks with love and knowledge, had not yet penetrated the times with its leaven and entered into everybody's food; it was fermenting still as a distinguishable vigorous enthusiasm in certain long-haired German artists at Rome, and the youth of other nations who worked or idled near them were sometimes caught in the spreading movement.
My nephew Nicholas, hot from school, with everything he learnt there, fermenting in his head, and nothing fermenting in his pocket, is just the man you want.
It could readily be guessed, though, that some great thought was fermenting in his brain.
if I dared own to any human creatu re what was at that very moment secretly fermenting in my mind.
If you have any experience with basic fermenting --like making and flavoring kombucha--making apple cider vinegar will be simple for you to pick up and a great way to use apple scraps.
These products are considered safe for consumption because of the low pH and the production of antimicrobial substances by fermenting organisms [4].
Though it's common to ferment Chardonnay in oak barrels to impart texture and flavor--and fermenting reds in large, upright wood casks was once standard--fermenting red wines in small oak barrels is a fairly new practice.
The origin of fermenting foods in Japan can be traced to China, circa 300 B.
Before refrigeration, people used fermenting to preserve foods.
During the process of fermentation, the leading fermenting bodies are microorganisms, but their population varies with fermentation conditions.