This drink gets a bad rap, and it’s understandable. When you order it in a typical bar, you’ll get a sickly-sweet rum and coke with a sad-looking wedge of lime on the side. The real one, though, is miles away. The difference is in the proportions; a real Cubra Libre needs one full part of lime juice to balance the sweetness of a mere 3 parts of cola.
Build in the order given in an ice-filled glass. Twist a lime wedge into the drink hard enough to release essential oils, and plunk the wedge right on top of the drink, so your drinker can smell those oils while they sip.