Apple Custard Pie

A terse nineteenth-century filling formula that assumes you already know how to line a pie plate and judge a custard. The proportions are given per pie and per three pies at once, so read them carefully before scaling.

• What the proportions actually meanThree eggs per pie, but one cup butter and one cup sugar spread across three pies — so roughly 1/3 cup each of butter and sugar per pie, with 3 eggs. Reading "one cup butter" as per-pie will give you something closer to a pudding of fat.
• Apple quantity is not givenThe original leaves it to judgment, and no figure can be reconstructed from the text. Stew and sieve enough apple to fill your shells once the eggs and butter are stirred in, and adjust to your plates.
• "Sour apples"Period shorthand for a tart cooking apple, not a cider or crab apple. Bramley, Granny Smith or Rhode Island Greening all work; a sweet modern eating apple will make the pie cloying at this sugar level.
• Rub through a colanderThis is the step that makes it a custard rather than an apple pie — you want a smooth purée, not pieces. A food mill or a fine sieve does it faster; a blender also works but gives a slacker texture.
• Dry the purée"Not much water left in them" is the hinge. A wet purée will weep and the custard will not set cleanly, so keep the pan uncovered and stir until the apple mounds on the spoon.
• No milk or creamUnlike most custard pies, the liquid here is entirely apple. Do not add dairy to loosen it; if it seems stiff, that is correct, and it will slacken once the butter melts in.
• Crust and bakingThe original gives no oven instruction. Pour into unbaked pastry shells; as a modern working equivalent, bake at 400F for 15 minutes, then reduce to 350F for 25 to 30 minutes, until the centre is set with only a slight wobble. Use a plain lard or butter pastry.
• YieldAs written, the proportions cover three pies; the size and whether they are single-crust are not stated. To make one, use 3 eggs with 1/3 cup each butter and sugar.