Tulloch, who works at the Wray & Nephew headquarters in Kingston, has been "nosing" rum for the firm for more than 50 years. He invites me to sniff eight different types of rum myself, ranging from a light, unaged, low-ester rum to a heavy, aged, high-ester sample. Each, I notice, has its own distinctive bouquet. The less fragrant, more neutral rums, Tulloch explains, are produced in modern column stills; the others are distilled in traditional copper pot stills. In the latter, he adds, more aromatic compounds are retained, so the resulting rum tends to be more robust. But pot stills are costly and time-consuming to operate, and many of the rum-producing islands of the Caribbean have abandoned them. Not Jamaica—which claims to use more pot stills for rum production today than any other country. "To operate a pot still is a skill that is handed down," says Tulloch. "It's a secret."