How to Make Key Lime Pie

According to Jean A. Voltz, author of The Flavor of the South, Key lime pie originated when a newfangled canned food product arrived in Florida in the mid-19th century. During this time, there were few cows in the Florida Keys. In 1856, sweetened condensed milk—a new food invention—arrived on the scene, offering a ready source of milk for the area.

Fortunately for us, someone soon discovered that sweetened condensed milk, eggs, and lime juice made a wonderful filling for a pie. Not just any limes were used—the original recipes for Key lime pie filling called for locally harvested Key limes, which are about the size of large walnuts and yellow-green in color, both inside and out.

Good news for people who don't live in Florida: There's no need to chase all over town to find true Key limes for our easy Key lime pie filling. Regular (Persian) limes make a wonderful pie as well. The real secret is to use fresh lime juice, not bottled, for the best flavor.

What about the crust? Some Key lime pie recipes are made with a pastry crust, others with a graham cracker crust. There's no definitive answer as to which crust is the more authentic Key lime pie crust, and both make a great pie. Another small difference is that some cooks top their Key lime pie recipes with luscious dollops of sweetened whipped cream, while others top them with airy meringue.

Our easy recipe for Key lime pie calls on a graham cracker crust and whipped cream—features that make the dessert simple yet keep it true to its origins.

Get our Key Lime Pie recipe here

To make a homemade Key lime pie from scratch, you'll need:

• One 9-inch homemade graham cracker piecrust or 1 purchased deep-dish graham cracker piecrust
• 3 large egg yolks
• One 14-ounce can (1-1/4 cups) sweetened condensed milk
• 1 teaspoon grated lime peel
• 1/2 cup fresh lime juice (you'll need about 20 Key limes or 4 medium regular (Persian) limes
• 3 tablespoons water
• A few drops green food coloring, if desired
• 1 cup heavy whipping cream
• 2  tablespoons powdered sugar
• 1/2 teaspoon vanilla

While there may be some disagreement on the Key lime pie crust options (graham cracker versus pastry), most everyone agrees that a Key lime pie filling should be anchored by sweetened condensed milk, lime juice, and eggs. Here's how to make the filling for our easy Key lime pie recipe:

1. Preheat the oven to 325 degrees F.
2. In a medium bowl whisk together the egg yolks using a wire whisk or fork. Gradually whisk in the sweetened condensed milk until smooth. Add the grated lime peel, fresh lime juice, water, and if you like, a few drops green food coloring. Mix well. The mixture will thicken.
3. Spoon filling into the prepared crust.
4. Bake the pie in the preheated oven for 25 minutes. Transfer to a wire rack and cool for 1 hour. Cover loosely and chill for 3 to 4 hours.

Looking for a Key lime pie with cream cheese filling? Try this recipe!

Key Lime Cheesecake Bars

While some Key lime pie recipes call for meringue topping, we love the way whipped cream provides a sweet and cool contrast to a tart and tingly Key lime pie filling. Here's how to top your Key lime pie:

• Chill a medium mixing bowl and the beaters.
• In the chilled bowl beat 1 cup heavy whipping cream, 2 tablespoons powdered sugar, and 1/2 teaspoon vanilla with an electric mixer on medium speed until soft peaks form.
• Spoon or pipe whipped cream onto the cooled pie or individual pieces. If desired, garnish with lime slices or fresh berries.

Tip: Be sure to cover and chill any leftover pie within 2 hours of serving.

The irresistible sweet-tart flavors of Key lime pie work well in other desserts, too. Check out these recipes for Key lime pie. Also take a look at luscious recipes that are takeoffs on Key lime pie with cream cheese filling: Key Lime Tassies, Tropical Dream Tassies, and Key Lime Cheesecake Bars. We even have Key Lime Pie Cupcakes, topped with a wonderful Key lime frosting. 

Whipped Key Lime Pie

Key Lime Tart

Key Lime Pie Tassies

Tropical Dream Tassies

Key Lime Cheesecake Bars

Key Lime Pie Cupcakes