This easy key lime pie recipe only calls for 3 ingredients for the filling and it can be made as an unbaked or baked version.

Overhead view of a classic key lime pie that is decorated with piped whipped cream and lime wedges

In 2014, my husband and I went to Florida to visit his parents for the first time since they moved there. While there, I had the best Key Lime Pie I had ever tasted. It was likely that this was the first time I had ever had it made with real, fresh, key lime juice. I was determined to recreate it when I returned home.

Ingredients in Key Lime Pie

The description on the menu stated that the filling only used 3 ingredients:

  1. sweetened condensed milk
  2. key lime juice
  3. pasteurized egg yolks

I also read through a lot of the history of key lime pie. Most people think that it originated in the Key’s around 1856 when fresh milk was not available and canned milk was new. This is why sweetened condensed milk is traditional.

Key Limes vs Persian Limes

The limes that were available in the area were also very tiny and a bit different from what you would traditionally find in the grocery stores these days. Typical limes are also known as Persian limes and are much larger and more tart than key limes. Key limes are very small and have a brighter lime flavor.

The extra effort it takes to extract the juice from key limes is absolutely worth it for this pie. That is if you can find key limes. They aren’t as readily available as Persian limes, and are typically only sean between June and September. If you can’t find key limes then use Persian limes instead! But I recommend staying away from bottled lime juice. Fres will always taste much better.

Bowl of limes and someone holding a key lime on the left and a persian lime on the right with text over the image indicated which is which

How to Make Key Lime Pie

Honestly, the most difficult part about making this pie is juicing the limes and waiting for it to solidify. Everything else comes together in a snap! This is a great pie to make with kids.

The Crust

While there are a few things that key lime purists agree about, including that the pie must be pale yellow in color to be authentic, there is some disagreement about what type of crust should be used. Graham cracker crust or shortcrust?

The original pie probably didn’t have a crust, but I prefer graham cracker with this kind of pie. It just feels right to me.

Slice of key lime pie on a white plate with a fork

Baked or Unbaked?

The second point of contention is if the pie should be baked or unbaked. The general consensus seems to be that the original Key Lime Pie was unbaked. I believe this is the kind of pie I ate in Florida because the menu made a point that the eggs were pasteurized.

Because lime juice is so acidic it works to denature the proteins in the egg yolks which helps it to gel and set. I have made this pie as an unbaked version several times. However, I find that baking it for a very short period of time helps to set the filling more firmly, which I prefer.

Note: Make sure that you purchase sweetened condensed milk and not evaporated milk, as the cans look very similar. If you do not have access to it, you can make homemade sweetened condensed milk with only milk and sugar.

The Topping

There is also a debate about meringue versus whipped cream versus nothing on top. The one I had in Florida didn’t have a topping and it was awesome as is. But I prefer just a tiny bit of lightly sweetened whipped cream to balance the tartness.

Overhead view of a classic key lime pie that is decorated with piped whipped cream and lime wedges

Chilling the Pie

The last point I’ll make before we dive into the recipe is that you need to make sure this pie is completely chilled before slicing it, otherwise it will not set. I actually really love to slice the pie once it is set and keep some pieces in the freezer to eat frozen. The pie doesn’t get completely rock solid in the freezer and it is such a lovely cold treat!

Overhead view of a classic key lime pie that is decorated with piped whipped cream and lime wedges
Yield: 1-9" Pie

Easy Key Lime Pie with Graham Cracker Crust

Prep Time 6 hours 30 minutes
Cook Time 12 minutes
Total Time 6 hours 42 minutes

This easy key lime pie recipe only calls for 3 ingredients for the filling and 3 ingredients for the graham cracker crust! The pie can also be made as a baked or unbaked version.


For the Crust

  • 200 grams (2 cups) graham cracker crumbs
  • 113 grams (1 stick, 8 tablespoons) unsalted butter, melted
  • 50 grams (1/4 cup) granulated sugar

For the filling

  • 788 grams (2-14 oz cans) sweetened condensed milk
  • 5 egg yolks
  • 227 grams (1 cup, 240 mililiters) key lime juice
  • 1 teaspoon lime zest (optional)


For the Crust

  1. Heat oven to 350°F/175°C.
  2. Pulse your cookies in a food processor or put them in a ziplock bag and roll a rolling pin over them until they become coarse crumbs.
  3. Combine the graham cracker crumbs, melted butter, and sugar in a bowl and mix until all of the cookie crumbs are coated in butter.
  4. Press the crumbs into a 9-inch (23 cm) deep-dish pie plate. Use medium pressure to press the crumbs evenly along the bottom and up the sides of the pie plate.
  5. Bake crust for about 12 minutes until lightly browned.

For the Filling

  1. Zest 1-2 of the limes (if using), and juice the limes.
  2. Combine the lime juice, lime zest (if using), egg yolks, and condensed milk in a bowl and whisk until combined.
  3. Pour the filling into the pie crust (it doesn't have to be completely cooled) and bake at 350°F/175°C for 12-14 minutes, until the filling is thickened but still slightly jiggly in the center.
  4. Allow the pie to cool at room temperature for 1 hour and then refrigerate for a minimum of 6 hours before slicing.
  5. The pie will hold under refrigeration for up to 4 days.
  6. Garnish with whipped cream, lime zest, and lime slices if desired.


Traditionally the filling for this pie remains unbaked. If you would like to leave it unbaked you can. The acidity from the lime juice will help the egg yolks to gel and allow the filling to set. However, it will not set quite as firm as it does when you bake it for a short period of time.

Recipe adapted from The Yearling Restaurant Key Lime Pie Recipe

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    Nutrition Information:

    Amount Per Serving: Calories: 0