Ron Zacapa of Guatemala and Flor de Caña of Nicaragua have both developed something of a following in the United States in recent years, but the most important brand of Costa Rican rum, Ron Centenario, remains relatively unknown. Indeed, even in Costa Rica, the rum isn’t famous. One valet at Hacienda AltaGracia tried to convince me that Centenario was Guatemalan, much to his embarrassment when he looked up the brand on his smartphone.