Soft Caramel Custard

A one-line variation that assumes you have the book's Soft Custard in front of you. Everything hinges on the caramel and on not overheating the custard.

• The base it refers toSoft Custard in books of this period is a stirred pouring custard: milk, egg yolks (sometimes whole eggs or a mix), sugar, a pinch of salt, vanilla stirred in off the heat. Proportions vary from book to book, so work from the book's own Soft Custard rather than an assumed formula. It is a sauce, not a set baked custard.
• What "caramelized sugar" meantGranulated sugar melted dry in a heavy pan until it is deep amber, often let down with a little boiling water to make a pourable syrup. Cooked to amber and no further; past that it turns acrid and the custard tastes scorched rather than caramel.
• The half cup is ambiguousThe original does not say whether it means half a cup of sugar before melting or half a cup of finished caramel syrup. Half a cup of sugar caramelized and loosened with 2 tablespoons water is the reasonable reading, and it will sweeten the custard noticeably, so cut the sugar called for in the base recipe by roughly half.
• Adding caramel to milkHot caramel and cold milk spatter violently. Add the milk to the caramel a little at a time off the heat, or stir the caramel syrup into the milk in the pan before it goes on the burner, which is what "before scalding" directs.
• ScaldingBring the milk to about 180F, when it steams and shows a ring of small bubbles at the edge. It need not boil, and boiling after the eggs go in will curdle it.
• DonenessTemper the hot milk into the yolks, return to low heat, and stir constantly until the custard reaches 170-175F and coats the back of a spoon. A period double boiler makes this nearly foolproof; over direct heat it can go from thickened to scrambled in seconds.
• If it curdlesPull it off the heat at once, pour through a fine sieve, and whisk hard or blend briefly. Mildly broken custard usually comes back; fully scrambled does not.
• Yield and servingWhatever quantity the book's Soft Custard makes, filling small cups or sauced over cake, poached fruit or steamed pudding. Serve warm or well chilled.