Caramel Ice Cream

A caramel custard base for a hand-cranked freezer, written as a variation on the book's Vanilla Ice Cream II. The whole dish turns on how the caramel meets the hot custard.

• Caramelize the second half of the sugar dryMelt about two-thirds of a cup of sugar in a heavy pan over medium heat until it is deep amber, then pour it into the hot custard in a thin stream while stirring. Adding it fast, or adding cold custard to hot caramel, makes it seize into a hard lump that then takes patient stirring over heat to dissolve again.
• Expect it to spatterMolten sugar is well above 300F and the custard is wet; the mixture will hiss and steam violently at the moment of contact. Use a deep pan, a long spoon, and keep your hand clear of the rising steam.
• Cook the custard to a temperature, not a lookOne egg and a tablespoon of flour thickening two cups of milk gives a thin, flour-stabilized custard typical of the period. Cook it over low heat or a double boiler to 175F, until it coats a spoon, then strain.
• Vanilla goes in coldA tablespoon and a half of extract is a generous amount by modern standards and much of it will flash off if it is stirred into a hot pan. Add it once the base has cooled, and taste before churning.
• Chill hard before freezingCombine the strained caramel custard with the quart of cream and refrigerate the base to 40F or below, ideally overnight. A warm base overruns badly in a modern machine and freezes coarse in an old ice-and-salt freezer.
• Freezer equivalentsCrank freezers of the period were commonly packed around three parts crushed ice to one part rock salt, though this recipe does not say. In a domestic machine, churn in batches of about a quart of base at a time, roughly 20 to 25 minutes, then ripen in the freezer for four hours before serving.
• YieldThree pints of dairy plus the sugar gives close to two quarts finished, or twelve to sixteen servings.