According to the Guinness website, "The story goes that Guinness Extra Stout and Champagne were first combined to mark Prince Albert's death in 1861, when the steward at Brook's Club in London ordered that even the Champagne should be in mourning, dressed all in black."
Strictly speaking, the black velvet is not a cocktail – it's a mixed drink. A cocktail has to include a spirit.
© Macclesfield Quiz League 2019