Name: Authentic Key Lime Pie with Graham Cracker Crust
Prep time: 20 min
Cook time: 25 min
Total time: 3 h 45 min
Yield: 8 slices
Cuisine: American
Ingredients: 1.5 cups graham cracker crumbs (about 12 full crackers crushed fine); 3 tbsp granulated sugar; 6 tbsp unsalted butter (melted); 4 egg yolks (room temperature); 2 tsp lime zest (from Key limes or regular limes); 0.5 cup fresh Key lime juice (bottled works in a pinch, about 15 to 20 Key limes); 14 oz sweetened condensed milk (one standard can); 1 cup heavy whipping cream (cold); 2 tbsp powdered sugar; 0.5 tsp vanilla extract

Jump to Recipe

Key lime pie holds a special place in my kitchen. My mom made it every summer without a recipe card in sight, and learning to recreate that tangy, custardy filling was one of the first times cooking felt like something I could actually master.

This recipe keeps everything simple and honest. You'll find no fancy equipment, no hard-to-source ingredients, just real flavor from fresh lime juice, a press-in crust, and a filling that sets up beautifully every time.

Authentic Key Lime Pie with Graham Cracker Crust

A bright, creamy, perfectly tart Key lime pie built on a buttery homemade graham cracker crust that comes together with just a handful of pantry staples.

4.9 (120 reviews)

Prep20 min

Cook25 min

Chill time3 hr

Total3 hr 45 min

Serves8 slices

Ingredients

Graham Cracker Crust

1.5 cups graham cracker crumbs , about 12 full crackers crushed fine
3 tbsp granulated sugar
6 tbsp unsalted butter , melted

Key Lime Filling

4 egg yolks , room temperature
2 tsp lime zest , from Key limes or regular limes
0.5 cup fresh Key lime juice , bottled works in a pinch, about 15 to 20 Key limes
14 oz sweetened condensed milk , one standard can

Whipped Cream Topping

1 cup heavy whipping cream , cold
2 tbsp powdered sugar
0.5 tsp vanilla extract

Instructions

Make the Crust

Preheat your oven to 350 degrees F. Grab a 9-inch pie dish and set it nearby.

Combine the graham cracker crumbs, sugar, and melted butter in a medium bowl. Stir until the mixture looks like wet sand and holds together when you press it between your fingers.

Press the crumb mixture firmly and evenly into the bottom and up the sides of your pie dish. Use the flat bottom of a measuring cup to pack it down tight.

Bake the crust for 8 minutes until it smells toasty and feels set. Let it cool for 10 minutes while you make the filling.

Make the Filling

Beat the egg yolks and lime zest together in a large bowl for about 2 minutes. The mixture will turn a pale, creamy yellow and that is exactly what you want.

Pour in the sweetened condensed milk and mix on medium speed for another 3 minutes until thick and smooth.

Add the lime juice and stir gently by hand until fully combined. The filling will look thin at first but it sets up in the oven.

Pour the filling into your cooled crust and spread it evenly to the edges.

Bake for 15 minutes. The center should have just a slight jiggle when you nudge the pan. It firms up as it cools.

Let the pie cool completely on a wire rack, about 30 minutes at room temperature, then transfer it to the fridge for at least 3 hours before slicing.

Finish with Whipped Cream

When you are ready to serve, pour the cold heavy cream into a large bowl. Add the powdered sugar and vanilla.

Beat with a hand mixer on medium-high speed until soft peaks form. This takes about 2 to 3 minutes. Do not over-beat.

Dollop or pipe the whipped cream onto each slice right before serving and add a thin lime round on top if you like.

Tips & Notes

Fresh juice makes a real difference here. Bottled Key lime juice works but fresh juice gives you that brighter, more floral flavor that makes this pie memorable.
Press your crust firmly. A loose crust crumbles when you cut the pie. Really pack it in with the back of a spoon or measuring cup.
Do not skip the chilling time. Three hours is the minimum, but overnight is even better. The filling needs that cold rest to slice cleanly.
Room temperature egg yolks blend more smoothly into the condensed milk. Pull them from the fridge about 20 minutes before you start.
If you can only find regular limes at the store, use those. The flavor is slightly less floral but still genuinely delicious.

Storage: Cover the pie tightly with plastic wrap or store slices in an airtight container in the refrigerator for up to 4 days. Add whipped cream only to individual slices right before serving, not to the whole pie ahead of time. The pie can also be frozen without the topping for up to one month. Thaw overnight in the fridge before serving.

Nutrition per serving · estimated

480 Cal

26g Fat

57g Carbs

7g Protein

1g Fiber

44g Sugar

210mg Sodium

Authentic Key Lime Pie with Graham Cracker Crust step-by-step

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Why Key Lime Pie Works Every Time

The magic of this pie is in the chemistry. Acid from the lime juice reacts with the proteins in the egg yolks and the condensed milk, which means the filling actually begins to set before it even hits the oven. That is why just 15 minutes of baking is all you need.

Sweetened condensed milk pulls double duty here. It adds both sweetness and a thick, creamy body to the filling without requiring any extra thickening agents. This is one of those recipes where keeping it simple is the right call every single time.

Getting the Most Juice from Key Limes

Key limes are small and a little fussy to juice, but the payoff is worth it. Roll each lime firmly on the counter with the palm of your hand before cutting it. That breaks down the interior and you will get noticeably more juice from each one.

If Key limes are not available at your grocery store, Persian limes work well as a substitute. The flavor is a bit bolder and less delicate, but we are still talking about a genuinely excellent pie. Use the same amount of juice and zest and you will be in great shape.