Frozen Tom and Jerry

This is a frozen custard — essentially a rich vanilla-less ice cream — flavored with the rum and brandy of the old Tom and Jerry punch. The one thing that matters is when the spirits go in.

• Add the liquor late, and for good reasonAdd the liquor late -- Alcohol depresses the freezing point, so spirits stirred in at the start slow the set and can leave the texture coarser. The instruction to freeze to a mush first, then add the rum and brandy and finish, follows that logic; follow it.
• Cooking the custardSix yolks with two cups milk and 3/4 cup sugar wants gentle heat in a heavy pan or double boiler, stirred constantly, until it coats a spoon — 170-175F. It will not thicken much further, and past about 180F the yolks curdle.
• Straining and chillingStrain while hot to catch any set egg, then chill thoroughly before adding the cream. A warm base freezes coarsely.
• "Cream" in this book"Cream" here -- Cream sold in this period was often thinner than today's heavy cream, closer to light cream or half-and-half, though grades varied. Heavy cream will give a denser, richer result; a mix of half heavy cream and half whole milk is likely nearer the original texture.
• Freezing equipmentPresumably written for a hand-cranked freezer packed with crushed ice and coarse salt; period directions commonly give something on the order of three parts ice to one of salt. A modern machine with a pre-frozen canister does the same job; churn to soft-serve stage, add the spirits, then churn a few minutes more.
• Firming upThe alcohol will keep this a little softer than a plain custard ice, so expect it to scoop easily rather than set hard.
• YieldAbout 1 1/2 quarts.