Definition

1. Noun:
   • A commercial leavening agent containing yeast cells: A substance, typically a frothy foam, consisting of live yeast used to ferment sugars and cause dough to rise in baking or in the production of alcoholic beverages like beer or whiskey.

Usage

• Noun:
  • The baker added barm to the bread dough to make it rise.
  • Traditional brewers often skim barm from the top of fermenting beer to use in other batches.

Advanced Usage

• Historical/Culinary Context: In historical and artisanal contexts, "barm" refers specifically to the frothy, yeast-rich foam formed on the top of fermenting malt liquors, which was traditionally used as a leavening agent before the commercial production of standardized yeast.
  • The recipe called for a spoonful of barm from the ale vat to start the bread.

Variants and Related Words

• Barmy (adj): An informal British English term meaning foolish or crazy. (Note: This is a distinct, idiomatic usage not directly related to the noun 'barm').
  • That's a barmy idea!

Synonyms

• Yeast: A more common general term for the microorganism used as a leavening agent.
• Leaven: A substance used to produce fermentation in dough.
• Ferment: An agent causing fermentation.

Notes on Different Meanings

• The primary meaning of "barm" is the yeast-based leavening agent. The adjective "barmy" (meaning crazy) is considered a separate lexical item derived from an old slang term, not a direct variant of the noun's core meaning.

Noun

1. a commercial leavening agent containing yeast cells; used to raise the dough in making bread and for fermenting beer or whiskey