In 1935 Highway Traveler magazine mentioned “icebox lime pie” as a specialty of the Florida Keys. The first key lime pies were made over 100 years ago in Key West with whole pelican eggs- without a meringue top. Later, Key West homemakers switched to chicken eggs and discovered that the whites ruined their pies. Since nothing was wasted, the homemakers added meringues to the pies to make use of the egg whites. Condensed milk (invented in 1856) was used because of the lack of fresh milk and refrigeration until the arrival of tank trucks with the opening of the Overseas Highway in 1930. But condensed milk turned out to be a successful necessity because it makes the pies really smooth.
Key lime pie has been traced back to the early 20th century in the Key West, Florida area. Its exact origins are unknown, but the first formal mention of Key lime pie as a recipe may have been made by William Curry, a ship salvager, and Key West’s first millionaire when his cook, “Aunt Sally”, made the pie for him. If such is the case, however, it is also possible and maybe even probable that Sally adapted the recipe already created by local sponge fishermen. Sponge fishermen spent many consecutive days on their boats, and stored their food on board, including nutritional basics such as canned milk (which would not spoil without refrigeration), limes and eggs. Fresh milk was not a common commodity in the Florida Keys before modern refrigerated distribution methods. Sponge fishermen at sea would presumably not have access to an oven, and, similarly, the original recipe for Key lime pie did not call for cooking the mixture of lime, milk, and eggs.
Today, Key lime pie is an American dessert made of Key lime juice, egg yolks, and sweetened condensed milk in a pie crust. The traditional Conch version uses the egg whites to make a meringue topping. The dish is named after the small Key limes (Citrus aurantifolia ‘Swingle’) that are naturalized throughout the Florida Keys. While their thorns make them less attractive, and their thin, yellow rinds more perishable, Key limes are tarter and more aromatic than the common Persian limes seen year-round at grocery stores in the United States. Key lime juice, unlike regular lime juice, is a pale yellow. The filling in a Key lime pie is also yellow, largely because of the egg yolks.
During mixing, a chemical reaction between the proteins of the egg yolks and condensed milk with the acidic lime juice occurs that causes the filling to thicken on its own without requiring a thickening agent. Early recipes for Key lime pie were not baked but relied on this reaction to produce the proper consistency of the filling. Today, because consuming raw eggs can be dangerous, pies of this nature are usually baked for a short time. The baking also thickens the texture more than the reaction alone.
On July 1, 2006, the Florida House of Representatives and the Florida Senate both passed legislation {HB 453} and {SB 676} selecting “Key Lime Pie” as the official pie of the state of Florida.
Key Lime Pie
Crust:
1 ½ cups almond flour or graham cracker crumbs
1/4 cup powdered sugar or powdered sugar alternative (such as Lakanto monk fruit)
1/4 cup salted butter, melted
Filling:
4 egg yolks
2 teaspoons lime zest
1 (14-ounce) can of sweetened condensed milk or sugar alternative sweetened condensed milk
2/3 cup freshly squeezed Key lime juice or store-bought
Meringue Topping:
4 egg whites
¼ teaspoon, cream of tartar
2 tablespoons powdered sugar or powdered sugar alternative (Lakanto)
Whipped Cream Topping:
1 cup heavy or whipping cream chilled
2 tablespoons confectioners’ sugar
Directions
For the crust
Preheat the oven to 325 degrees F.
In a medium bowl, whisk together the almond flour, sweetener, and salt. Stir in melted butter until the dough comes together and resembles coarse crumbs. Turn out into a glass or ceramic 9-inch pie plate. Press firmly with fingers onto the bottom and up the sides of the pan. Use a flat bottomed glass or measuring cup to even out the bottom.
Bake until the edges are golden brown, about 10-12 minutes.
Set aside on a wire rack; leave the oven on and turn the oven temperature to 350 degrees F.
For the filling
In an electric mixer with the wire whisk attachment, beat the egg yolks and lime zest at high speed until very fluffy, about 5 minutes. Gradually add the condensed milk and continue to beat until thick, 3 or 4 minutes longer. Lower the mixer speed and slowly add the lime juice, mixing just until combined, no longer. Pour the mixture into the baked crust. Bake for 10 minutes, or until the filling has just set.
Turn the oven temperature to 400 degrees F.
For the meringue topping
With a mixer, beat egg whites with cream of tartar until soft peaks form. Gradually beat in the sugar until stiff peaks form. Spread the topping over the filling and seal to the edge of crust. Bake for 5-8 minutes or until meringue is golden brown.
Note: Watch the oven and don’t take your eyes off the meringue, it could brown quickly. Place in the refrigerator and let it chill for 2-3 hours.
For the whipped cream topping
Whip the cream and the confectioners’ sugar until nearly stiff. Cut the pie into wedges and serve very cold, topping each wedge with a large dollop of whipped cream.
