Just as certain cocktails call for a particular style of rum, there are times—when making the Petit Punch Vieux, for one—when you simply must have sirop de canne. That's French for cane syrup; it's a richer alternative to simple syrup made by many of the same distilleries in the French-speaking Caribbean that make rhum agricole. Both products are made from fresh sugarcane juice; in the case of sirop de canne, it's a matter of slowly reducing the sweet liquid until it thickens and takes on a deep golden hue.
Some distillers embellish their sirops with spices and other flavorings; vanilla, a popular addition, makes a delicious complement to a floral or woody rum. Not every liquor store carries the stuff, however, and if you find yourself shaker in hand and without the time to mail order, you can make a respectable approximation in your own kitchen. Here's how:
Heat 1 1/2 cups Demerara sugar, 3 whole cloves, 3 whole allspice berries, 1 cinnamon stick, 1 vanilla bean with its seeds scraped and reserved, and 1 cup water in a 2-qt. saucepan over medium-high heat.
Cook, stirring occasionally, until the sugar is dissolved. Remove from heat and cool. Your homemade sirop de canne will keep in the refrigerator for up to a month and make quite a few tasty tropical drinks.