Club soda is carbonated water to which minerals have been added to enhance the flavor. Potassium bicarbonate and potassium citrate are the minerals that are usually added. Sodium is another, but not all club sodas contain sodium. Because of its high carbonation level and elevated flavor profile, club soda has long been the bartender's choice for cocktails, however many people enjoy club soda on it's own as a lively alternative to alcoholic beverages in a social setting.