The Secrets to Making a Key Lime Pie That Tastes Like Summer

While there's a lot of lore surrounding Key lime pie, this classic American dessert couldn't be easier. No special equipment or hard-to-find ingredients are required; in fact, a Key lime pie filling requires just a handful of ingredients, all of which can be found at just about any supermarket in the country. And yes, you can go ahead and skip the hassle of sourcing those elusive Key limes (unless you really want to go that route). Here, you'll learn how to make Key lime pie the easy way; you'll also find all the answers to frequently asked questions, like how long to bake Key lime pie and how long you can store it.

What Is Key Lime Pie?

Key lime pie is a custard-style pie that's flavored with limes and gets extra richness from sweetened condensed milk. It's made with either a graham cracker crust or pie pastry and can be topped with whipped cream or meringue.

So, where did Key lime pie originate? The Florida Keys, of course! According to Jeanne A. Voltz, author of The Flavor of the South, Key lime pie's origin dates to 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. It wasn't long before some genius cook paired the newfangled product with eggs and locally grown Key limes and made a wonderful filling for a pie.

Key Lime Pie Ingredients

While cooks don't always agree on which kind of crust (pastry or graham cracker) to use or whether to top the pie with meringue or whipped cream, the ingredients in Key lime pie filling are generally quite straightforward: You'll need limes, egg yolks, heavy cream, and sweetened condensed milk. Food coloring is optional, but it adds an eye-catching light green color that hints at the burst of lime flavor to come.

So, how many Key limes to make a pie? To get the ½ cup of lime juice needed to make our Traditional Key Lime Pie recipe, you'll need 36 of those little walnut- to golfball-size yellow-green limes. However, 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.

For the topper and crust, you'll need just a handful of other ingredients. To top your pie with meringue, use egg whites—you'll have some leftover when you separate the eggs for the egg yolks in the filling. You'll also need cornstarch, vanilla, and cream of tartar. For an easier topping, opt for sweetened whipped cream. All you'll need for that is heavy cream, sugar, and vanilla.

How to Make a Key Lime Pie

Key lime pie is one of the easiest desserts you can make, especially if you start with a purchased crust and finish with whipped cream instead of meringue. The first step, of course, is finding a good recipe. Our tried-and-true recipe for Traditional Key Lime Pie, tested and perfected in our Better Homes & Gardens Test Kitchen, is as classic as it gets. Follow the recipe to make the crust, stir together the 5-ingredient filling, bake, cool, chill, and top with your chosen topper.

If you're looking for a Key lime pie filling that goes a little easier on the fat and calories, try our Lightened Key Lime Pie.

How Long to Bake Key Lime Pie

You might find an old recipe for Key lime pie that uses raw egg yolks without baking the filling. Toss that recipe! For food safety's sake, a Key lime pie filling containing raw eggs must be baked to a safe internal temperature (160°F). How long to bake Key lime pie depends on the recipe. Our recipe specifies 35 minutes in a preheated 350°F oven.

Wondering how to tell if Key lime pie is done? The best test is to use an instant-read food thermometer. The filling is done when it reaches 160°F.

How Long Does Key Lime Pie Last?

After baking, you should cool the pie on a wire rack for 1 hour; then, cover the pie and chill it in the refrigerator for 8 to 24 hours. After a day, the crust can start getting a little soggy, so enjoy it at its freshly made best—within a day of baking it.

So, can you freeze Key lime pie? Sadly, because it's a custard-style pie, we don't recommend it. However, if you're looking for a Key lime pie that's great for freezing, try our wonderful Whipped Key Lime Pie.

Now that you know how to make Key lime pie, you'll always have a tart, tingly, sweet, rich, and refreshing dessert to serve after a robust meal. But don't stop there. Enjoy the Key lime pie concept in a variety of other desserts. For example, try our Key Lime Cheesecake Bars—think of this recipe as an easy Key lime pie with cream cheese filling. For serving a crowd, bake some Key Lime Pie Cupcakes or Key Lime Pie Tassies. You can even start the morning in a Key Lime-luscious way with our Key Lime Danish Pastries.