Arthur Guinness began brewing his famous Irish stout in a brewery at St. James's Gate in Dublin, Ireland in 1759. The beer is based on the porter style that originated in London in the early 18th century. It is one of the most successful beer brands in the world, and is exported worldwide. Guinness Stout is also brewed under license internationally in several other countries. The unfermented hopped Guinness wort extract (essence) is shipped from Dublin and is used in brewing beer locally outside Ireland. The distinctive feature in the flavour is the roasted barley which remains unfermented. A thick creamy head is produced by the use of nitrogen when being served. This drink is extremely popular with the Irish and, in spite of a decline in consumption over recent years, is the best-selling alcoholic drink of all time in Ireland. Drinking a pint of this brew is an experience which should not be missed.