Green’s Dictionary of Slang

inferior, insignificant, worthless.

1641		T. Heywood Vertue of Sack 4: That would preach down thy worth in small-beer prose.
a.1666		A. Brome ‘To his Friend that had Vowed Small-Beer’ in Chalmers Eng. Poets II (1810) 648/ I: Dost thou think by turning anchorite, Or a dull small-beer sinner, Thy cold embraces can invite, Or sprightless courtship win her?
1680		M. Stevenson Wits Paraphras’d 76: Ye Gods, that such a smal-beer Trooper, / Not worthy scarce to kiss thy Crupper.
1797		‘Peter Pindar’ ‘Ode To the Livery of London’ Works (1801) V 49: Those fellows talk to me – the small-beer dregs!
1840		E. Howard Jack Ashore II 124: ‘Perhaps, sir,’ said Mr. Dwindlebink, in a small-beer voice.
1865		G.A. Sala My Diary in America I 275: English chroniclers of small-beer tours.
1877		J. Greenwood Dick Temple I 24: A pair of small-beer roysterers.