Purity Brewing Company has launched Gnarly, a limited edition strong black beer featuring a champagne style bottle. Promoted as a “deeply indulgent, beautifully balanced beer”, Gnarly is brewed with a variety of Marris Otter, Crystal Rye, Smoked and Black Malts, hopped with Northern Brewer, Cascade, Chinook and conditioned for six months in traditional oak whisky casks. Paul Halsey, managing director of Purity, said: “Gnarly uses champagne yeast which gives the …