# fermentation

/ˌfɝmənˈteɪʃən/ (US) · /fɜːmɪntˈeɪʃən/ (UK)

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

## Senses

### 1. chemical process

noun · CEFR B2 · Technical

a process where yeast or bacteria break down sugar into alcohol or acid.

For teachers: the anaerobic breakdown of organic substances by microorganisms, such as the conversion of sugars into ethanol or lactic acid.

- The fermentation of the grapes takes several weeks before the wine is ready.
- Industrial fermentation requires precise temperature control to ensure that the yeast cultures remain active throughout the conversion process.

Usage: Often used as an uncountable noun when discussing the general process.

Teaching tip: While technical, this is a high-frequency word for learners interested in cooking, brewing, or biology.

### 2. social agitation

noun · CEFR C2 · Literary · Formal

a state of social or political excitement and change.

For teachers: a state of agitation, unrest, or intense activity, often preceding significant social or political change.

- The country was in a state of political fermentation before the revolution.
- The intellectual fermentation of the late eighteenth century provided the necessary groundwork for the radical shifts in governance that followed.

Usage: Usually used in the singular or as an uncountable noun.

Teaching tip: This sense is metaphorical; it compares the 'bubbling' of a chemical reaction to the 'bubbling' of social unrest.

## Examples

- The fermentation of the dough takes several hours.
- Traditional kimchi relies on the natural fermentation of cabbage and spices to develop its signature sour flavor.
- Industrial fermentation processes are now used to produce not only food and beverages but also biofuels and pharmaceutical compounds like insulin on a massive scale.

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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.