Apple Pie Filling Recipe

Apple pie filling is six sliced Granny Smith apples simmered for ten minutes in a syrup of brown sugar, cinnamon and cornstarch, then finished with butter and vanilla. It takes 30 minutes, fills one 9-inch pie and keeps five days in the fridge. The cornstarch only sets once the syrup reaches a full boil — below that it stays thin and tastes chalky.

Which apples to use

The filling stands or falls on the apple. Granny Smith is firm and tart, so the slices stay whole through ten minutes on the stove and another forty in the oven, and the tartness keeps three-quarters of a cup of sugar from tasting like candy. Honeycrisp and Braeburn hold their shape almost as well and bring more sweetness of their own.

McIntosh and Red Delicious go the other way: they collapse into sauce. When King Arthur Baking baked six varieties side by side, Granny Smith slices held their shape and McIntosh turned to chunky applesauce at a touch. That is not a flaw if you want it — a half-and-half mix of Granny Smith and McIntosh gives whole slices suspended in a softer, spoonable base.

Slice to a quarter inch. Thinner slices turn to mush before the syrup has thickened; thicker ones stay crunchy in the middle.

How to make apple pie filling

Cooking the filling before it goes into the crust solves the two problems of a raw-apple pie. Raw slices shrink as they bake and leave a hollow under the top crust; cooked slices have already shrunk. And raw apples release their juice into the pastry while it bakes, which is why so many bottom crusts come out pale and soft. Here the juice is bound into the syrup before the crust ever meets it.

A few notes on the ingredients:

• Two sugars. Brown sugar gives the syrup its colour and a molasses depth; granulated sugar keeps that depth from turning into toffee. All brown and the filling tastes like caramel apples — pleasant, but not pie.
• Cornstarch, not flour. Both leave the syrup a little cloudy, but flour turns it opaque and pasty and you need noticeably more of it for the same thickness. Three tablespoons of cornstarch for six cups of apples and three-quarters of a cup of water gives a filling that holds a clean edge when the pie is cut without turning to jelly.
• Lemon juice does two jobs: the acid slows the browning of cut apples, and it sharpens a syrup that would otherwise be one-note sweet.
• Water can be swapped for apple cider one-to-one. Cider adds a rounder apple flavour and a little more sugar, so the filling will taste sweeter with the same amount of sugar.

Ingredients

• 6 medium Granny Smith apples (about 2 1/2 pounds), peeled, cored and sliced 1/4 inch thick
• 1/2 cup granulated sugar
• 1/4 cup packed light brown sugar
• 3 tablespoons cornstarch
• 1 teaspoon ground cinnamon
• 1/4 teaspoon ground nutmeg
• 1/4 teaspoon salt
• 3/4 cup water
• 1 tablespoon lemon juice
• 2 tablespoons unsalted butter
• 1 teaspoon vanilla extract

Instructions

1. Whisk the granulated sugar, brown sugar, cornstarch, cinnamon, nutmeg and salt together in a wide saucepan, then whisk in the water until no lumps remain. Cornstarch only disperses cleanly in cold liquid; added to hot syrup it seizes into clumps.
2. Bring the syrup to a boil over medium-high heat, stirring, and let it bubble for 1 minute until it turns glossy and thick enough to coat the spoon.
3. Add the apple slices and lemon juice, stir to coat and reduce the heat to medium. Cook for 8 to 10 minutes, stirring often, until the apples are tender at the edges but still hold their shape.
4. Take the pan off the heat and stir in the butter and vanilla until the butter has melted into the syrup.
5. Cool completely before spooning into a pie crust — about 1 hour at room temperature, or refrigerate. Warm filling softens the raw pastry underneath it.

Getting the thickness right

Cornstarch does nothing until the liquid boils. A syrup that has merely simmered will look fine in the pan and run out of the pie — which is why King Arthur's thickener guide tells you to leave a fruit pie in the oven until the filling bubbles up through the crust. Here the boil happens on the stove instead: the syrup is boiled for a minute before the apples go in, so the thickening is done and visible, and the apples then only need to soften.

The reverse failure is boiling too long. Cornstarch begins to break down under prolonged heat, and a filling that was thick at ten minutes can be thin again at twenty-five. Eight to ten minutes with the apples is enough; if the slices are still hard at that point, the problem is the variety or the slice thickness, not the time.

Two fixes, if it comes to that:

• Too thin after cooling: stir 1 teaspoon cornstarch into 1 tablespoon cold water, add it to the filling and bring it back to a boil for 30 seconds.
• Too thick to spoon: a tablespoon of water or cider, stirred in over low heat.

Storage and freezing

In an airtight container the filling keeps five days in the fridge. It freezes for up to three months; four cups is one 9-inch pie, so freeze it in that portion. Thaw in the fridge overnight. A cornstarch syrup loosens a little after freezing — if it looks wet, a minute at a boil brings it back before it goes into a crust.

Ways to use it

One batch is exactly one double-crust pie, but it is worth making two. The second one goes warm over Golden Diner pancakes or French toast in place of syrup, or cold over vanilla ice cream with a spoon of caramel sauce. It fills hand pies and turnovers, and it sits under a crumble topping with no changes at all. On a Thanksgiving table it makes a lighter counterpart to sweet potato pies.