Green’s Dictionary of Slang

red steer n.

(US) beer.

1944		Maurer & Baker ‘“Aus.” Rhyming Argot’ in AS XIX:3.
1981		P. Wright Cockney Dialect and Sl. 99: Beer can also be [...] red steer.
2001		J. Burkardt ‘Rhyming Sl.’ Wordplay 🌐 red steer beer.