Forms: 1 beorma, 3 beorme, berrme, 4–5 berm(e, 5–7 barme, (7 birme), 7– barm. [OE. beorma; prob. common Teut. (:—*bermon-), though early cognates are wanting; cf. Da. bärme, Sw. barma, Fris. berme, barm, LG. borme, barme, barm, mod.G. bärme.]
1. The froth that forms on the top of fermenting malt liquors, which is used to leaven bread, and to cause fermentation in other liquors; yeast, leaven.
c. 1000. Ags. Gosp., Matt. xiii. 33. Heofena rice is ʓelic beor.
c. 1200. Ormin, 996. Bræd All þeorrf wiþþutenn berrme.
c. 1386. Chaucer, Chan. Yem. Prol. & T., 260. Alum, glas, berme, wort.
c. 1420. Liber Cocorum, 39. With egges and floure in batere þou make, Put berme þer to.
1601. Holland, Pliny, II. 145. The froth or barme … [has] a property to keep the skin faire and cleare in womens faces.
1688. in Phil. Trans., XVIII. 130. His Brains worked like Birme in an Ale-Fat.
1816. Scott, Antiq., xi. The sea was working like barm.
b. transf. or fig. Ferment, fermenting agent.
c. 1580. Montgomerie, To R. Hudson. This barme and blaidry buists up all my bees.
1666. G. Harvey, Morb. Angl., iv. 48. I assert the gall to be the barm or ferment of the venal blood.
1828. Landor, Imag. Conv. (1846), II. 174. Milton’s dough … is never the lighter for the barm he kneads up with it.
† 2. The froth or ‘head’ of beer when poured out.
c. 1275. Sermun, in O. E. Misc., 188. Loȝe heo holdet hore galun, mid berme [v.r. beorme] heo hine fulleþ.
c. 1440. Promp. Parv., 32. Berme of ale or other lyke, spuma.
1483. Cath. Angl., 22/1. Barme, spuma.
3. attrib., as in barm-froth, barm-fly.
1606. Wily Beguiled, Prol. in Hazl., Dodsl., IX. 223. That barm-froth poet.
1676. Cotton, Angler, II. 335. Another Dun called the Barm-fly from its yeasty colour.
