We've recently joined a dinner club. Each month we get together to have dinner with three other couples and, each month, there is a different theme. Last month the theme was "Florida Cuisine" and I was responsible for bringing a dessert. After some web searches, it became obvious that the only choice for dessert was a key lime pie.
Fortunately, living in Florida, fresh key limes were in my neighborhood grocery. If you can't find fresh key limes in your area, you may be able to find bottled key lime juice. Regardless, you can always buy it online. In a pinch, you could use regular limes. But as you can see below, they are not the same. Key limes are small little things. A bugger to juice, truth be told. But the flavor is distinct. This pie is not overly sweet. It is tart and has a slight bitter twist to it, kind of like what I associate with most grapefruit.
You start with the crust. This is a graham cracker crust. It has a little extra sugar in the crust, again to help balance that tart punch. I mix mine in a food processor and then dump it into a pie pan. Spread it out with your hands and then use a cup of some kind to press it down and make it even. Bake the pie crust while you prepare the limes.
Before you juice, you'll need to zest enough of them to obtain one loose tablespoon. Then you can cut the limes and juice away. Because they're so small, they can be tiring to juice. If you have one of those squeeze type juicers, you may be better off than I was. You need 2/3 cup of juice, which requires approximately one pound of key limes. Don't juice your limes too early, as the juice can develop additional bitterness when it sits too long.
Don't be dismayed if your crust comes out of the oven looking really funky. It tends to puff up when baking, but returns to normal dimensions as it cools. The first time I made this crust I thought I had ruined it when I first took it out of the oven Don't fret, it'll work itself out.
As the pie cools, you can mix up the filling. Start by mixing the egg yolks and zest together. Mix on medium-high for a few minutes until the mixture has increased slightly in volume and is thick and pale yellow (with green flecks in it, of course).
The next step is to add a can of sweetened condensed milk. This is some very thick, sweet stuff. So sweet, in fact, that it provides all the sweetness this pie needs. By the way, please note the proper color of this product. If you open your can and find that it is a caramel brown color, as I did when I first made this pie, perhaps you are not using sweetened condensed milk often enough, or, as in my case, not rotating your stock well. The date on my can of brown sweetened condensed milk? "Best by Nov 2004." Yikes! And, even more pressing, how many stinking military moves did that can of milk participate in, anyway, before I ended up throwing it away? Needless to say, I will be more vigilant.
Bake the pie at the same temperature as you baked the crust for 25 minutes. The pie filling will be set and maintain its shape upon gentle shaking, but will not be brown in any way. Remove from the oven and let cool to room temperature.
I think this pie requires a little sweet border to help balance it out. I like a whipped topping. You could make whipped cream right before serving, but I think piping a stabilized whipped cream border really looks like a million bucks. I like to then zest a little lime on the border for color. Be sure to thoroughly chill the pie before serving. This pie keeps well and can be made one to three days in advance.
Key Lime Pie
Yield: one 9" pie
Adapted from King Arthur Flour
1 1/2 cups graham cracker crumbs (one pouch plus two whole crackers)
1/4 cup powdered sugar
1 egg yolk
1/3 cup melted butter
1 TBS loosely packed key lime zest
3 large egg yolks
1 14-ounce can sweetened condensed milk
2/3 cup fresh (or bottled) key lime juice
whipped cream and additional lime zest for garnish (optional)
Mix together the crust ingredients. Pour into a 9" pie pan. Spread evenly and pack down with a measuring cup. Bake at 325° F for 15 minutes. Crust may look uneven and strange upon removal from the oven, but will return to a more normal shape upon cooling. Let crust cool while preparing filling. Leave oven on at 325° F.
Beat the zest and egg yolks together on medium-high speed for a few minutes, until the yolks have increased in volume and become thickened and a pale yellow. Add the sweetened condensed milk and beat on a fairly high speed for 2-3 minutes. Lastly, add the lime juice. Stir until well incorporated, but do not over mix. Pour into the baked crust and return to the oven to bake for 25 minutes. The filling will be set and no longer loose in the middle, but will not be browned in any way. Let cool to room temperature. Prepare and pipe a border of stabilized whipped cream, if desired. Refrigerate for at least four hours before serving.
This pie keeps well and can be made 2-3 days in advance.