Classic key lime pie pours a tart, silky filling of key lime juice, sweetened condensed milk, and egg yolks into a buttery graham cracker crust, bakes it briefly, then chills it until cool, firm, and ready for a cloud of whipped cream.
Only a handful of ingredients and one mixing bowl are needed. The filling is whisked, not cooked on the stove, and a short bake sets it into a smooth custard that balances sharp citrus with creamy sweetness in every slice.
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Why This Classic Key Lime Pie Recipe Works
Condensed milk makes the filling effortless. Its thick sweetness balances the sharp lime juice, and it sets with the egg yolks into a dense custard without any starch or thickener.
Real lime juice gives the right bite. Fresh juice tastes bright and floral, while regular limes work with a slightly different flavor that is a bit sharper and less aromatic.
A toasted crust adds crunch. Baking the graham crumbs with butter for a few minutes makes them firm and fragrant, so the crust stays crisp under the creamy filling.
Ingredients for Classic Key Lime Pie
- For the crust you need one and a half cups of graham cracker crumbs and six tablespoons of melted butter, pressed into a nine inch pie pan.
- For the filling use one fourteen ounce can of sweetened condensed milk, half a cup of key lime juice, and four egg yolks, with one cup of whipped cream for the top.
Graham cracker crumbs: Crush them finely and mix with the butter until the crumbs look like damp sand, so the crust holds together.
Sweetened condensed milk: Use sweetened condensed milk, not evaporated milk, which lacks the sugar and thickness the filling needs.
Key lime juice: Bottled key lime juice is convenient and consistent. Regular lime juice works, though the flavor is a little less floral.
Egg yolks: Beat them until thick and pale so they blend smoothly and help the filling set.
Whipped cream: Whip it just before serving for a light, cool topping that balances the tart filling.
How to Make Classic Key Lime Pie
1. Heat the oven. Heat the oven to 350 degrees F and lightly grease a nine inch pie pan.
2. Make the crust. Mix the graham crumbs with the melted butter, press the mixture firmly into the pan, and bake for five to seven minutes until fragrant.
3. Beat the yolks. Beat the egg yolks in a bowl until thick and light yellow.
4. Add the milk and lime. Stir in the sweetened condensed milk, then the lime juice and a little zest if you like, until smooth.
5. Fill and bake. Pour the filling into the warm crust and bake for ten to fifteen minutes, until the center jiggles slightly and reaches 160 F.
6. Cool and chill. Cool the pie at room temperature, then chill it for at least three hours before topping with whipped cream and slicing.
How to Serve Classic Key Lime Pie
Top slices with whipped cream and a little lime zest. Fresh fruit pavlova and New York cheesecake suit a dessert table, fresh strawberry pie adds a berry option, and buttermilk lemon pound cake offers another citrus treat.
How to Store and Reheat Classic Key Lime Pie
Cover the pie and refrigerate it for up to three days. Do not leave it out for more than two hours, and do not freeze it, because the filling can turn watery after thawing. Add whipped cream just before serving for a cleaner look.
Tips and Variations for Classic Key Lime Pie
Flag the allergens. This pie contains milk, egg, and wheat, so label it clearly for guests with allergies.
Do not taste raw filling. Do not taste the filling before baking, because it contains raw egg yolks.
Check the set. The filling should jiggle slightly in the center and reach 160 F, then finish setting in the refrigerator.
Bake the crust first. A short bake keeps it from turning soggy under the wet filling.
Zest first. Zest the limes before squeezing them, which is much easier than zesting squeezed fruit.
Chill overnight. The pie slices more cleanly after a full night in the refrigerator.
Use a hot knife. Dip the knife in hot water and wipe it between slices for clean edges.
Check trusted guidance. Read the University of Wisconsin Extension leftovers guidance for safe handling of egg desserts.
Frequently Asked Questions About Classic Key Lime Pie
How long should classic key lime pie bake?
Ten to fifteen minutes at 350 degrees F, until the center jiggles slightly and the filling reaches 160 F.
Can I use regular limes in classic key lime pie?
Yes. The flavor is a little sharper and less floral, but the texture is the same.
Can I make classic key lime pie ahead of time?
Yes. Bake it a day ahead, chill it overnight, and top it with whipped cream just before serving.
Why is my filling runny?
It may have been underbaked or not chilled long enough. Bake until the center barely jiggles and chill at least three hours.
Can I use a store bought crust?
Yes. Bake it briefly first to keep it crisp under the filling.
Classic Key Lime Pie
Equipment
- Nine inch pie pan
- Mixing bowl
- Whisk
- Instant read thermometer
Ingredients
Main Ingredients
- 1 cup graham cracker crumbs plus 1/2 cup more
- 6 tbsp unsalted butter melted
- 14 oz sweetened condensed milk one can
- ½ cup key lime juice fresh or bottled
- 4 large egg yolks
- 1 cup whipped cream for topping
Instructions
Cooking
- Crust. Mix the crumbs and butter, press into a pan, and bake at 350 degrees F for five to seven minutes.
- Beat. Beat the yolks until thick and light.
- Mix. Stir in the condensed milk and lime juice.
- Bake. Pour into the crust and bake ten to fifteen minutes until 160 F.
- Chill. Cool, then chill at least three hours and top with whipped cream.
