Lemon Pie

A compact lemon meringue pie built on a cornstarch custard rather than a flour paste. The order of operations matters more than anything else here: the shell is baked empty, the filling cooked separately on the stove, and the meringue given only enough oven time to colour.

• The hinge: cook the starch outIn a double boiler the mixture thickens slowly and can taste chalky if pulled too early. Whisk the cornstarch and sugar with the boiling water until it thickens and turns glossy, then hold it another 3-4 minutes before adding the yolks, or the starch flavour will persist under the lemon.
• Temper the yolksBeat a few spoonfuls of the hot starch mixture into the yolks first, then return everything to the pan. Adding cold yolks straight to hot custard gives you threads of scrambled egg. Cook 2-3 minutes more after the yolks go in, and stir in the lemon juice off the heat so the acid does not thin the starch.
• Blind-baking the shell"Bake under-crust" means the shell goes into the oven empty, which the recipe requires since the filling is already cooked and the pie only returns to the oven to colour the meringue. The recipe gives no temperature or time; a modern working equivalent is a hot oven, around 400F, with the pastry lined and weighted until set, then unweighted until the base is dry. A pale, damp shell will go soggy the moment the warm filling meets it.
• "Powdered sugar"In books of this period powdered sugar often meant finely ground granulated sugar, closer to today's caster sugar than to modern confectioners' sugar with its cornstarch. Either works for the meringue; caster dissolves cleanly and gives a less soft set.
• Meringue proportionsThree tablespoons of sugar to two whites is a lean, old-style meringue. It will brown quickly and is more prone to weeping. Two tablespoons of sugar per white gives a more stable foam if you want one.
• Browning temperature"Set in oven to brown" implies a hot oven and a short stay, though the recipe specifies neither; watch it rather than trusting a clock. Spread the meringue over filling that is still warm and seal it to the pastry rim all the way round, which helps prevent shrinkage and a watery layer underneath.
• YieldThe recipe names no pan size; this quantity of filling suits about an 8-inch shell, and a 9-inch pan needs roughly a quarter to a third more. It cuts into six modest wedges.
• CoolingCool at room temperature for at least two hours before cutting. Refrigerating a meringue pie while warm draws beads of moisture onto the surface.