Firewine was a Klingon alcoholic beverage.
Worf once tried to order firewine from an holodeck's barmaid. (TNG: "A Fistful of Datas")
Relm commented that she drank a lot of firewine and was still able to pilot a Norexan-class dreadnought as though she didn't drink alcohol. (RIS Bouteina: "Bottle to Throttle")