Used to describe cold weather, this saying derives from the traditional Navy phrase "cold enough to freeze the balls off a brass monkey". This references the brass structure or 'monkey' where cannon balls were stacked. 'Mad as a hatter'

There's no denying that the Beastie Boys were responsible for popularizing the Brass Monkey, but the origins of the drink are much more mysterious. In fact, the Brass Monkey they were rapping about was not orange juice and beer (or malt liquor), but a canned precursor to Smirnoff Ice.

"Cold enough to freeze the balls off (or on) a brass monkey" is a colloquial expression used by some English speakers to describe extremely cold weather.

The Brass Monkey is a cocktail made with dark rum, vodka and orange juice, sold as a premixed cocktail in the 1970's and 80's. It was sold by the Heublein Company, which later dissolved in 1998.