Ironically, despite the immense popularity of beer in Quebec and in Canada generally, the non-alcoholic "soda" version has maintained a more widespread appeal. The commercial versions are alcohol-free but spruce beer is often home-brewed in bathtubs and bottled on rooftops in order to allow the sunlight to aid with natural fermentation. Although commercial production of this non-alcoholic style has grown in recent years, the main provider is still famed casse-croute restaurant Paul Patates in Montreal - using a recipe dating from 1896. Notwithstanding its relative obscurity, spruce beer is an authentic Canadian style of beer, as well as one of the oldest forms of beer in North America.