Sorbet of Rum

A rum-and-lemon water ice built on a base given earlier in the chapter — a sugar syrup and fruit ice churned until slushy. The two things that decide whether it works are the timing of the alcohol and the softness of the final texture.

• Add the rum at the end, and no more than statedAlcohol depresses the freezing point, so rum stirred into the base will keep it slack and grainy. The recipe's three tablespoons go into an already-frozen sorbet, which keeps the alcohol from interfering with the set.
• A quarter of a pintIn an American book of this period that is half a cup, 4 fluid ounces; in British measure, 5 fluid ounces. Either way it is roughly the juice of three or four lemons, strained free of pulp and seeds.
• "Fine old Jamaica rum"A dark, heavy pot-still rum with pronounced molasses and ester character. A modern aged Jamaican rum is the closest match; a light white rum will read as sweetened alcohol and nothing more.
• Sweetness matters more when frozenCold blunts sugar perception, so the syrup base should taste faintly too sweet at room temperature. Adding the lemon juice before churning will also thin the base, which is why the sugar cannot be cut back much.
• ChurningAn ice-cream machine gives the right texture in 20 to 30 minutes. Worked by hand in a freezer, scrape and beat the mixture every 30 minutes for two to three hours; the aim is a soft, spoonable slush, not a solid block.
• "Serve it with the roasts"This is a mid-meal palate cleanser, served in glasses between the heavier courses rather than as dessert. At 2 to 3 ounces a portion, a quart serves ten to sixteen.
• Holding itWith the rum in, the sorbet will set softer than it otherwise would and will slump fairly quickly out of the freezer. Chill the glasses and scoop at the last moment.