For altitudes lower than 10,000 feet, this meringue is stabilized with a cooked cornstarch gel to ensure a smooth, stable foam. The yolks are cooked to sufficiently heat and kill the enzymes that could break down the filling and make it runny.
From “Pie in the Sky,” this recipe is for 5,000 feet, makes a 9-inch pie and serves 6-8.
Ingredients
Coconut-crumb crust:
- 1 1/3 cups graham or vanilla wafer cookie crumbs
- 2 tablespoons granulated sugar
- 1/2 cup shredded sweetened coconut (or replace with 1/2 cup more crumbs)
- 5 1/2 tablespoons unsalted butter, melted
Filling:
- 1 cup granulated sugar
- 1/3 cup cornstarch
- 1/4 teaspoon salt
- 1 1/2 cups water
- 4 large egg yolks, room temperature
- 2 tablespoons unsalted butter, room temperature
- 1 1/2 tablespoons grated lemon zest
- 1/2 cup fresh lemon juice
- 3 tablespoons graham or plain cracker crumbs
Meringue topping:
- 3/4 cup plus 2 tablespoons granulated sugar
- 1 tablespoon cornstarch
- 1/2 cup water
- 6 large egg whites, room temperature
- 1/8 teaspoon salt
- 1/2 teaspoon cream of tartar
- 1/2 teaspoon vanilla extract
Directions
Place rack in center of oven and preheat to 350 degrees.
Prepare crumb crust: Toss crumbs, sugar, coconut and melted butter in a medium bowl. Turn crumbs into pie plate and press into a solid layer on pan bottom and sides, using the back of a large spoon. Or cover crumbs with a sheet of plastic wrap, then press firmly with your hand.
Bake shell 7-8 minutes, until slightly darkened in color. Cool crust on a wire rack. Turn off oven, then reheat it shortly before browning meringue topping.
Prepare filling: In a heavy-bottomed 1 1/2- to 2-quart saucepan, whisk sugar, cornstarch and salt. Whisk in water, scraping whisk into corners of pan to incorporate all dry ingredients.
Set pan over medium-high heat and stir until it reaches a full, hard-bubbling boil. Then whisk constantly for 1 full minute, until filling thickens, looks clear, and generously coats the back of a spoon. This can take 6-7 minutes at 5,000 feet, longer at higher elevations.
In a medium bowl, whisk yolks, then whisk in about 1/2 cup of the hot lemon mixture to warm them. Scrape warmed yolks back into pan, whisking hard to blend mixture before yolks scramble. Return pan to stovetop over medium-high heat, and stir continuously while bringing mixture to a full, bubbling boil (with bubbles breaking on the surface), then boil, stirring, for a full 4 minutes (set a timer) to cook yolks so they will remain stable and not break down into a runny filling. Remove pan from heat and stir in butter until it melts, then stir in lemon zest and juice. Set filling aside to cool to room temperature.
To prepare meringue up to nearly 10,000 feet: (For 10,000 feet and above, go to denverpost.com/food). First make a stabilizer gel: In a small saucepan, stir 2 tablespoons sugar, cornstarch and water until cornstarch dissolves. Set over high heat and whisk 2-3 minutes (slightly longer at 5,000 feet and above) until mixture bubbles into a full bubbling boil, starts to thicken, and looks almost clear. (Note: At high altitudes, evaporation occurs quickly; don’t overcook gel, or too much water will evaporate, making it too thick.) Remove from heat and transfer gel to a small bowl.
Preheat oven to 350.
To whip egg whites, place them in the large bowl of an electric mixer, and check to make sure whites no longer feel cold. Add salt and cream of tartar and whip on medium-high speed just until foamy. Gradually whip in remaining 3/4 cup sugar; increasing mixer speed to high, but watch closely: As soon as you start to see beater tracks on top of whites, stop machine.
Stir gel to be sure it is still soft. While slowly whipping whites, add vanilla and, little by little, scrape in cooled cornstarch stabilizer (if it is too hot, it will collapse the meringue). Watch whites carefully, observing stiffness of the foam. You want almost stiff peaks with a tip that just begins to fall over slightly when beater is lifted. The whites should be thick, glossy, and smooth.
Once meringue is prepared, set it aside for a minute and return pot of lemon filling to stove. Stir it over very low heat just until it is almost too hot to touch; it needs to be hot to poach the bottom of the meringue that will cover it.
When it is hot, spoon it into prepared crumb crust, smooth top, and sprinkle on 3 tablespoons crumbs, to absorb any excess moisture from meringue. Add about half the meringue and spread it out onto edges of crust to seal it and prevent shrinking. Pile on remaining meringue and shape swirls with the back of a spoon.
Bake at 350 18-23 minutes, or until meringue looks a rich golden brown color. Cool pie on a wire rack and serve at room temperature or chilled. Refrigerate any leftovers.
