South Side – IBA

The South Side is a gin sour built with lemon juice, sugar, and mint, and its early history is genuinely contested rather than settled. The oldest known trace is a 1913 magazine mention of a "Gordon's South Side," a gin-and-lemon frappé served over crushed ice. The first printed recipe under the name "South Side Fizz" appeared in Hugo Ensslin's Recipes for Mixed Drinks, a 1916 New York bartending manual, as a mint-flecked variant of a Gin Fizz.

Three rival origin stories persist. One traces the drink to the South Side Sportsmen's Club, a private Long Island hunting and fishing club of the 1890s, where a Mint Julep is said to have evolved into the new cocktail. Another credits Manhattan's speakeasy the 21 Club, which popularized the drink during Prohibition and is often called its house cocktail, though it more likely spread it than invented it. The most famous story ties the drink to Chicago's South Side and gangster Al Capone, holding that his gang doctored harsh bootleg gin with citrus, sugar, and mint while North Side rivals simply mixed theirs with ginger ale. This version is widely repeated but is undercut by the fact that the recipe was already in print while Capone was still a teenager living outside Chicago.

The drink's name is generally read as pointing either to the Chicago neighborhood or to the Long Island club, without a documented consensus on which. The International Bartenders Association first added the South Side to its official list in a 2020 revision, and it sits today in the New Era category.