Refreshingly cool and silky, Key lime pie is welcome on all summer picnic tables—and all holiday tables, dinner tables, or birthday tables, for that matter.
The combination of Key lime juice, zest, condensed milk, and egg yolks yields a pie filling that is rich and tart without being cloyingly sweet. The perfect crust companion—graham cracker crust—lends sweetness and a bit of nutty flavor, but it really is a vessel to hold the unforgettable filling.
We call this Key lime pie recipe heavenly because it's precisely where you'll think you've been transported after one bite. We've perfected this recipe over decades of making Key lime-flavored recipes, so we've really got the balance of the sweet-tart Key lime juice and the sweetened condensed milk just right.
Here, learn how to make key lime pie step by step. Plus, find out where this favorite citrus pie really originated.
Where Did Key Lime Pie Originate?
You're thinking Florida, right? There's hardly a restaurant menu in the Sunshine State without this dessert.
Turns out, the origins of the Key lime pie are a little murky. Some Florida historians believe the pie was invented in the Florida Keys in the late 1800s, but what can be proven is another story: A researcher found that the pie likely originated with a condensed milk manufacturer in New York City—except it was a lemon and condensed milk pie in this earliest iteration. Then, savvy Florida bakers swapped lemons for local Key limes, and Florida's favorite pie was born.
Still, if you're transported to a tiny island with a tropical drink in hand after one bite, you're not alone. Let them fight over the origins. We'll have another slice of pie, please.
Key Lime Pie Ingredients
This Key lime pie really is simple. We've kept the ingredient list short and sweet so it's ultimately an easy key lime pie. Here, the things you'll need to gather to make this pie:
- A graham cracker crust: We prefer a homemade one if you have the time, but a store-bought shortcut is always appreciated.
- Sweetened condensed milk: This ingredient creates the base of the rich, luscious pie filling. It's sweet and creamy, which is precisely what this pie needs.
- Key lime juice and zest: Key limes can be hard to find when they're not in season (which is June through September in Florida but year-round in other places). But bottled Key lime juice is usually always available.
- Egg yolks: This helps set the filling so it doesn't run when you slice into the pie.
- Whipped cream: Here's another place where we think homemade is so much better that we encourage you to do it if you have time (it's part of the recipe below). But store-bought whipped topping is also acceptable in a pinch.
How To Make Key Lime Pie
Full instructions for making a Key lime pie are below, but here's a brief recap:
- Step 1: Make the filling. Once you have your crust prepared, it's time to make the filling, which includes the sweetened condensed milk, lime juice, lime zest, and egg yolks. Pour the filling into the graham cracker crust.
- Step 2: Bake the pie. Even though this pie is ultimately served chilled, you need to bake the pie to set the filling. This takes about 15 minutes. Then, let the pie cool for an hour before putting it in the refrigerator to chill for an hour.
- Step 3: Top with whipped cream. Get out your stand mixer or hand mixer, and whip up the cream and powdered sugar. Dollop it onto the chilled pie, and add Key lime slices for garnish if you want.
How To Store Key Lime Pie
The pie needs to be served chilled, so keep it in the fridge until you're ready to slice and serve. Whipped cream will hold for a while, but if you're making this pie ahead of time, wait to whip the cream and top the pie until you're ready to present it.
Have leftovers? Cover the pie plate in plastic wrap, and keep it in the fridge up to 3 days.
Can you freeze Key lime pie?
Yes, you can freeze Key lime pie. But if you're planning to do that, bake it in a foil pan instead of your glass or metal one. And don't add the whipped cream. It won't make it through the freeze and thaw cycles.
Once baked, let the freezer-bound pie cool completely. Wrap the entire pan in plastic wrap, then aluminum foil. Label the pie with the food's name and the date you're putting it in the freezer. It can stay in the freezer up to 3 months.
When you're ready to enjoy it, take the pie out of the freezer, and let it thaw overnight in the fridge. Make the whipped cream topping just before serving.
Editorial contributions by Kimberly Holland.
Ingredients
1 (14-oz.) can sweetened condensed milk
3 egg yolks
2 teaspoons Key lime zest*
1/2 cup Key lime juice
1 (9-inch) graham cracker piecrust
1 cup whipping cream
3 tablespoons powdered sugar
Garnish: fresh Key lime slices*
Directions
Make filling:
Preheat oven to 350°F. Whisk together condensed milk and next 3 ingredients until well blended.
Pour mixture into piecrust.
Bake pie, then chill:
Bake at 350°F for 15 minutes or until pie is set. Cool completely on a wire rack (about 1 hour). Chill 1 hour before serving.
Top with whipped cream and garnishes:
Beat whipping cream at high speed with an electric mixer 2 to 3 minutes or until soft peaks form, gradually adding powdered sugar.
Top pie with whipped cream. Garnish, if desired.
Test Kitchen Tips
*Regular lime zest and slices may be substituted.
Chef's Note: We tested with Nellie & Joe's Famous Key West Lime Juice.