DictionarymotherFermentation film
noun

mother

A slimy film formed in fermenting liquids.

A mother forms on the surface as the vinegar develops.

Etymology

Probably a figurative use of mother for a substance from which more vinegar develops. The historical connection is uncertain.

More examples

  • Keep the vinegar mother in clean liquid.
  • The jar contains a thick mother.
  • She uses the mother to start another batch.

Forms

mother