Browned butter & allspice rum

Fat-washing rum gives a deep, buttery flavour with no greasiness. Melt 100g (3½oz) unsalted butter over a medium heat. Cook, stirring often, until the milk solids turn nut brown. Towards the end, add ½ teaspoon of crushed allspice berries. Remove from the heat and add 250ml (1 cup) rum. Cool, transfer to a container and refrigerate for 2 days. Skim off the solidified butter and strain the rum through a coffee filter. Use within 2 weeks in the following Barbadian cocktail formula: one of sour, two of sweet, three of strong, four of weak (perhaps 1 lime, 2 sugar syrup, 3 butter & allspice rum, 4 water).