Key West locals adhere to a few universals for Key lime pie. First, Key lime pie is never green, but rather a natural creamy yellow. It’s always made with small, round key limes (or authentic bottled key lime juice), not the large Persian limes found in grocery stores.
And any Key lime pie worth its weight—and taste—is made with sweetened condensed milk. Never milk. That’s because milk was unavailable in the Florida Keys until the 1930s with the opening of the overseas highway when tank trunks carrying ice could get to the islands.
Although tales of local Key Westers being the inventors of the original key lime pie, many historians credit local sponge divers as the first to combine the locally abundant limes with the condensed milk and eggs they had on their boats.
1 1/4 Cups Graham Cracker Crumbs from 9 (2 1/4-inch by 4 3/4-inch) crackers
2 Tbl. Sugar
5 Tbl. Unsalted Butter, melted
1 (14-oz) Can Sweetened Condensed Milk
4 Large Egg Yolks
1/2 Cup plus 2 Tbl. Fresh or Bottled Key Lime Juice
3/4 cup chilled heavy cream
Preheat oven to 350°F. Stir together graham cracker crumbs, sugar and butter in a bowl with a fork. Combine well. Press mixture evenly
onto bottom and up side of a 9-inch (4-cup) glass pie plate. Bake crust in middle of oven 10 minutes and cool in pie plate on a rack. Leave oven on. Make filling and bake pie:
Whisk together condensed milk and yolks in a bowl. Combine well. Add juice and whisk. Combine well (mixture will thicken slightly). Pour filling into crust and bake in middle of oven 15 minutes. Cool pie completely on rack (filling will set as it cools), then chill, covered, at least 8 hours.
Just before serving, beat cream in a bowl with an electric mixer until it just holds stiff peaks. Serve pie topped with cream.
Cooks’ note: Pie (without topping) can be chilled up to one day.