yeast vs barm

yeast and barm both are nouns.

Word	Noun	Adjective	Verb	Adverb
yeast	Yes	No	No	No
barm	Yes	No	No	No

As nouns, yeast and barm are synonyms defined as:

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

yeast (noun)	barm (noun)
any of various single-celled fungi that reproduce asexually by budding or division	a commercial leavening agent containing yeast cells; used to raise the dough in making bread and for fermenting beer or whiskey
a commercial leavening agent containing yeast cells; used to raise the dough in making bread and for fermenting beer or whiskey