I don’t remember the first time I had key lime pie, but I do remember exactly where I got this recipe: from an in-flight magazine at least 20 years ago. It was at the end of a two-page article in which author Ellen Kanner describes savoring real key lime pie as she was growing up. I taped the two pages together, punched holes on the side, and have kept it in my binder ever since.
Kanner described how key lime pie should be “tangy and sweet, bracing and cool, the crunch of the crust a perfect foil for the creamy filling.” And, of course, it must be yellow. Key limes are light yellow when they’re ripe — not green — so their juice is, too.
Some people garnish their pies with strips of green rind from regular limes, which I find OK, but I’d rather just have just a dollop of whipped cream. There is way too much flavor going on with the pie for me to want much more than that. I just want to dig in!
I do recommend making the graham cracker crust yourself. Although you can certainly use a prepared one, a homemade crust looks and tastes better, and is a lot easier to make than you might think. In just a few steps, you’ll have a buttery, crisp, delicious pie crust. (If you do use a store-bought crust, make sure it’s for a 9-inch pie — some are 10 inches and that’s too large.)
The ingredients here are the same as those in the magazine article from so many years ago, though I recently tweaked it to make the pie hold up better.
Graham cracker crust:
1 1/2 cups graham cracker crumbs
1/4 cup sugar
1/3 cup butter, melted
Combine all ingredients in a large bowl and press firmly into a 9-inch pie plate. Bake at 350F degrees for 10 minutes. Remove and let cool while you prepare the filling. Keep oven on.
Key lime pie filling:
4 egg yolks
1 14-oz. can sweetened condensed milk
1/2 cup + 1 Tbsp. key lime juice
With an electric mixer (not by hand!), beat the egg yolks until lemony*. Add the condensed milk and continue beating for about 3 minutes. Add the key lime juice and beat until slightly thickened, about 2 minutes. Pour into prepared pie crust and bake at 350F for 10 minutes. Remove, let cool, and refrigerate at least 6 hours before serving.
*What does “lemony” mean when beating egg yolks? It refers to the way the color of the yolks changes slightly and becomes yellower when they’re beaten. Egg yolks — along with whole eggs and egg whites — hold air bubbles well; the air that’s incorporated when you beat yolks makes them lighter in color.