The Dark 'n Stormy has only two main ingredients: ginger beer and dark rum. The ginger beer goes in first, in a tall glass filled with ice, and the rum is poured slowly on top. It floats and forms a dark layer over the lighter drink, like a storm cloud. The drink is then stirred, creating the cloud-like appearance. A slice of lime may accompany it.
The story is told by the Gosling family, who blend and sell rum in Bermuda. According to them, the drink originated after World War I at a ginger-beer factory linked to the Royal Navy officers’ club, whose members discovered that the local rum paired well with the beverage. The name, again according to the family, came from an old fisherman who compared the drink’s color to a cloud under which only a fool or a dead man would go to sea.
The rum is Gosling’s Black Seal. The family’s history on the islands begins in 1806, when James Gosling, son of a London wine merchant, was bound for America and, after 91 days of calm at sea, landed at St. George’s. The family later opened a shop on Front Street in Hamilton and began blending their own rum in the 19th century. The name Black Seal comes from the black wax used to seal the bottles.
The Gosling family registered Dark 'n Stormy as a trademark and maintains that only the drink made with Black Seal may use that name. The cocktail name is trademarked; that protection does not extend to any rum-and-ginger-beer mix. In Bermuda it is served in bars, restaurants, and parties and is called the national drink, a title it shares with the Rum Swizzle.