# ferment

/ˈfɝmɛnt/ (US)

Source: https://englishreference.com/word/ferment
Updated: 2026-08-27

## Senses

### 1. biochemical process

verb · CEFR B2 · Technical

to change a substance, like sugar, into alcohol or acid using yeast or bacteria.

For teachers: to undergo or cause fermentation, typically involving the anaerobic breakdown of organic substances by microorganisms.

- The grapes were left to ferment in large wooden barrels to make wine.
- If the mixture is kept at the correct temperature, the yeast will ferment the sugars into ethanol and carbon dioxide within a few days.

Usage: Can be used transitively (to ferment something) or intransitively (something ferments).

### 2. to stir up trouble

verb · CEFR C1 · Literary

to cause trouble, excitement, or social change.

For teachers: to incite or stir up trouble, disorder, or revolutionary sentiment.

- The new laws began to ferment a spirit of rebellion among the workers.
- Political activists worked tirelessly to ferment discontent among the rural population, hoping to trigger a widespread movement for reform.

### 3. social agitation

noun · CEFR C1 · Academic · Formal

a state of confusion, excitement, or change in a group of people.

For teachers: a state of agitation, unrest, or turbulent change within a society or organisation.

- The country was in a state of political ferment following the sudden election.
- The intellectual ferment of the late eighteenth century paved the way for radical shifts in scientific and philosophical thought.

## Examples

- The fermentation of the grapes takes several weeks.
- The local economy is currently in a state of ferment as new tech companies move into the area.
- The rapid fermentation of the sugar solution produced a significant amount of carbon dioxide, which the scientists monitored closely to ensure the reaction remained controlled.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.