English Reference
noun

fermentation

n.
US /ˌfɝmənˈteɪʃən/ UK /fɜːmɪntˈeɪʃən/ fer·men·ta·tion UK spelling fermentation's, fermentation's

  1. 01 B2 Upper Intermediate Technical Science

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

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

    Simple

    The fermentation of the grapes takes several weeks before the wine is ready.

    In context

    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.

    Teacher's tip

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

    chemical changezymosis
  2. 02 C2 Proficiency LiteraryFormal

    a state of social or political excitement and change.

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

    Simple

    The country was in a state of political fermentation before the revolution.

    In context

    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.

    Teacher's tip

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

In industrial production, bacteria are grown inside large fermentation tanks and given carbon-rich materials such as sugars, starch, or plant oils.

ScienceDaily· 17 Aug 2026

From Middle English fermentacioun, from Latin fermentātiō, fermentātiōnem. By surface analysis, ferment + -ation.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin fermentātiō
Level B2 · Upper Intermediate
Frequency Frequent
Updated