Key Lime Pie
By Janet Homme · Updated April 1, 2026
Key lime pie is the rare dessert that is both effortless and unforgettable, a study in the perfect balance of tart and sweet. The filling comes together in one bowl with just a few ingredients, no fussy custard cooking on the stove required, and it sets up silky and luscious in the oven. Against a buttery graham crust and a cloud of whipped cream, that bright lime tang is pure sunshine.
The classic filling is a small miracle of chemistry. Sweetened condensed milk, egg yolks, and lime juice combine and thicken simply from the acid in the limes, then a short bake sets them into a smooth, sliceable custard. It is one of the easiest pies you will ever make, which is part of why it has been a diner staple for generations.
While true Key limes give the most authentic flavor, regular Persian limes from the grocery store make an excellent pie and are far easier to juice. What matters most is using fresh juice rather than the harsh, slightly bitter bottled kind. The difference in brightness is night and day.
Do not be intimidated by the custard, either, because there is no tempering or careful stovetop work involved. You simply whisk the filling together, pour it into the crust, and let a short bake and a long chill do the rest. It is genuinely one of the most beginner friendly pies in any baker’s repertoire.
Below you will find the full method, from pressing a crust that holds together to knowing exactly when the filling is set. The only real test of patience is the chill time, which lets the pie firm up for clean, beautiful slices.
This is a wonderful make ahead dessert for exactly that reason, since it needs to chill anyway and only improves after a night in the fridge. Whether you finish it with billows of whipped cream or a toasted meringue, it is the kind of pie that disappears fast at any summer table.
Why you will love this
- One bowl filling: The custard thickens from the acid in the lime juice, so there is no stovetop cooking or tempering and almost no chance of curdling.
- Fresh lime juice: Real juice gives a bright, clean tang that bottled juice simply cannot match, and it is the heart of the whole pie.
- Egg yolks: The yolks enrich the filling and help it set into a smooth, sliceable custard with a luscious mouthfeel.
- Buttery graham crust: A baked crumb crust adds toasty crunch and a sturdy base that holds clean slices instead of crumbling.
- Whipped cream top: Lightly sweetened cream balances the tart filling and makes every bite feel luxurious and cool.
What you will need
This is a short list where freshness is everything. Buy plenty of limes for both juice and zest, and use a full fat can of sweetened condensed milk, which is the heart of the filling.
- Limes (about 4 to 6): You need both zest and a full half cup of juice, so buy extra; fresh juice is essential for the bright, clean flavor that defines this pie.
- Sweetened condensed milk (14 oz): This sweetens and thickens the filling, so use full fat for the proper silky set; low fat versions will not firm up the same way.
- Egg yolks (4): The yolks enrich the custard and help it firm up into a smooth, sliceable filling; save the whites for meringue or another use.
- Graham cracker crumbs (1.5 cups): Crush them fine so the crust presses together neatly and holds its shape under the fork.
- Unsalted butter (6 tablespoons): Melted butter binds the crust; a little extra makes it crisp and cohesive rather than dry and crumbly.
- Heavy cream (1 cup): Cold cream whips into the soft, billowy topping that balances the tart filling and makes each bite feel luxurious.
Equipment: You will need a 9 inch pie plate, a mixing bowl, a fork or food processor for the crumbs, a whisk, a fine zester, and a hand mixer or whisk for the cream.
How to make it, step by step
Step 1: Make the graham crust
Heat the oven to 350F. In a bowl, stir together the graham cracker crumbs, sugar, salt, and melted butter until the mixture looks like wet sand and clumps when pressed.
If the crumbs still seem dry and loose, add another tablespoon of melted butter. The right consistency holds together when you pinch it, which is what keeps the baked crust from crumbling under the fork.
You can crush the graham crackers in a food processor for the finest, most even crumbs, or seal them in a bag and roll over them with a rolling pin. Either way, aim for a sandy texture with no large shards that would create weak spots in the crust.
Step 2: Press and bake the crust
Tip the crumbs into a 9 inch pie plate and press them firmly and evenly across the bottom and up the sides. Use the flat bottom of a measuring cup to compact the base, which gives a sturdy, even crust.
Bake for 8 to 10 minutes, until the crust is fragrant and lightly golden at the edges. Leave the oven on and let the crust cool slightly while you make the filling; pouring filling into a warm crust helps it set evenly.
Baking the crust rather than just chilling it is worth the extra ten minutes, since it firms the butter and toasts the graham for a deeper, crisper base. A par baked crust also stands up far better to the moist filling without turning soggy.
Step 3: Zest and juice the limes
Zest the limes with a fine grater before juicing them, taking only the green layer and avoiding the bitter white pith. You want about a tablespoon of fragrant zest, which carries the brightest lime aroma.
Then juice the limes until you have a full half cup. Roll them firmly on the counter first and they will release far more juice; strain out any seeds as you go.
If you are using true Key limes, expect to squeeze quite a few, since they are small and contain little juice. Larger Persian limes give the same half cup from far fewer fruit and are perfectly delicious here. A handheld citrus press or reamer makes quick work of either kind and helps you extract every last drop of juice, which matters when you need a full, accurate half cup for the filling to set properly.
Step 4: Mix the filling
In a bowl, whisk the egg yolks with the lime zest for a minute or two until the mixture lightens slightly and looks pale. This brief whisking helps the yolks emulsify and tints the filling a soft green.
Whisk in the sweetened condensed milk until smooth, then add the lime juice and whisk gently to combine. The mixture will visibly thicken as the acid reacts with the milk, which is exactly what should happen.
Add the lime juice last and stir just until combined, since overmixing once the acid is in can thin the filling back out. The finished mixture should be smooth, pourable, and a pale, pretty green from the yolks and zest.
Step 5: Bake the filling
Pour the filling into the warm crust and smooth the top. Bake for 12 to 15 minutes, until the edges are set but the center still jiggles slightly when you nudge the pan.
Do not wait for the center to look firm; like any custard, it will continue to set as it cools. Overbaking causes cracks and a grainy texture, so pull it while the middle still has a gentle wobble.
The surface should look matte rather than wet and may have just begun to set into a soft skin.
Step 6: Cool and chill
Let the pie cool on a wire rack to room temperature, which takes about an hour. Cooling gradually prevents the filling from cracking as it sets.
Then refrigerate the pie, uncovered at first, for at least 3 hours and ideally overnight. The chill firms the custard into clean, sliceable wedges and lets the lime flavor settle and bloom.
Once the surface is cold to the touch, you can loosely cover the pie so it does not pick up other flavors from the fridge. Avoid pressing plastic wrap directly onto the filling, which can mar its smooth surface.
Step 7: Whip the cream
When you are ready to serve, pour the cold heavy cream into a chilled bowl with the powdered sugar and vanilla. Whip until it holds soft, billowy peaks that just hold their shape.
Stop while the cream still looks smooth and glossy, before it turns stiff or grainy. Soft peaks spread and dollop beautifully over the firm, tart filling.
Chilling the bowl and beaters first helps the cream whip faster and hold more air. If you want a topping that holds for longer at a party, whip it just slightly stiffer or add a teaspoon of powdered sugar more for stability.
Step 8: Top and serve
Spread or pipe the whipped cream over the chilled pie, either covering the whole surface or leaving a rim of green filling visible around the edge. Both look lovely, so go with whatever feels right.
Garnish with thin lime slices or a little extra zest for color and a hint of what is inside. Slice with a knife wiped clean between cuts for tidy wedges, and serve cold straight from the fridge. For the cleanest slices of all, dip the knife in hot water and wipe it dry between each cut so the filling does not drag.
A few fresh raspberries or a sprig of mint on each plate makes the pie feel special with almost no extra effort. The contrast of cool, tart filling against the buttery crust and soft cream is what keeps people coming back for a second slice.
Tips for the best results
- Use fresh juice: Bottled lime juice tastes harsh and bitter, so squeeze fresh limes for the brightest flavor.
- Zest before juicing: It is far easier to zest a whole lime than a squeezed one, so always zest first.
- Do not overbake: Pull the pie while the center still jiggles; it sets fully as it chills.
- Press the crust firmly: A well compacted crust holds together and gives clean slices instead of a crumbly mess.
- Chill fully: At least three hours in the fridge is what gives the pie its sliceable, set texture.
Variations and substitutions
- Meringue top: Swap the whipped cream for a baked meringue made with the leftover egg whites.
- Coconut crust: Add a quarter cup of toasted shredded coconut to the graham crust for a tropical note.
- Lime and ginger: Add a teaspoon of grated fresh ginger to the filling for a warm, spicy edge.
- Mini pies: Press the crust into a muffin tin and bake individual key lime tartlets for a party.
How to store and reheat
Store the pie covered in the refrigerator for up to 4 days; the flavor only improves after a day. Add the whipped cream just before serving, or refrigerate the topped pie and use it within a day for the freshest cream.
To freeze, wrap the cooled, untopped pie tightly and freeze for up to a month. Thaw it overnight in the fridge, then add fresh whipped cream before serving for the best texture.
What to serve it with
- Serve cold straight from the refrigerator
- Garnish each slice with a thin twist of lime
- Add a few fresh raspberries on the side
- Pair with iced tea or a cold sparkling drink
Frequently asked questions
No. While true Key limes give the most authentic flavor, regular Persian limes from any grocery store make an excellent pie and are much easier to juice. What matters far more is using fresh juice rather than bottled.
It was likely underbaked or not chilled long enough. The filling should jiggle only slightly in the center when it leaves the oven, then needs at least three hours in the fridge to set fully into sliceable wedges.
It is strongly discouraged. Bottled lime juice has a harsh, slightly bitter and metallic taste that comes through clearly in such a simple filling. Fresh juice gives the bright, clean tang that makes this pie special.
Save them for a meringue topping in place of the whipped cream, or use them in an omelet, financiers, or macarons. They keep covered in the fridge for several days or freeze well for later baking.
Yes, it is an ideal make ahead dessert. Bake and chill the pie up to a day or two in advance, since the flavor deepens as it rests. Add the whipped cream topping just before serving for the freshest result.
Key Lime Pie
A tangy, creamy key lime custard set in a buttery graham cracker crust and topped with lightly sweetened whipped cream.
Ingredients
- 1.5 cups (150g) graham cracker crumbs, about 11 full sheets
- 0.25 cup (50g) granulated sugar
- 6 tablespoons (85g) unsalted butter, melted
- 0.25 teaspoon fine salt
- 4 large egg yolks
- 1 tablespoon lime zest, from about 4 limes
- 14 oz (1 can) sweetened condensed milk
- 0.5 cup (120ml) fresh lime juice
- 1 cup (240ml) cold heavy cream
- 2 tablespoons powdered sugar
- 0.5 teaspoon pure vanilla extract
- Thin lime slices for garnish, optional
Instructions
- Heat oven to 350F and stir crumbs, sugar, salt, and melted butter together.
- Press the mixture into a 9 inch pie plate and bake 8 to 10 minutes.
- Whisk egg yolks with lime zest, then whisk in condensed milk and lime juice.
- Pour the filling into the warm crust and bake 12 to 15 minutes until just set.
- Cool to room temperature, then chill at least 3 hours until firm.
- Whip the cold cream with powdered sugar and vanilla to soft peaks.
- Top the chilled pie with whipped cream and garnish with lime.
Notes
- Use fresh lime juice rather than bottled for the brightest flavor.
- The filling should still jiggle slightly in the center when you pull it from the oven.
- Chill the pie fully so it slices cleanly and the flavor settles.