The dividing line between a Cuba Libre and a Rum & Coke may be faint, but exploring the boundary is a worthwhile diversion. Havana bartenders typically use Cuban-made tuKola in place of Coca-Cola, and the amount of rum is sometimes left to the drinker’s discretion, with the server or bartender waiting with an expectant “just say when” expression as the rum pours. Read more about the drink's history here.