Key Lime Pie is a creamy and refreshing pie with just the right amount of tartness, all topped with a homemade whipped topping. For a slightly sweeter pie, try my Lemonade Pie!
Key Lime Pie
Key Lime Pie is considered the official pie of the Florida Keys, and everyone claims to have the authentic recipe! I stuck with the traditional ingredients of the key lime juice, egg yolks, and condensed milk for this recipe. I went with homemade whipped topping and a graham cracker crust, but some may argue that it needs a meringue topping with a pastry crust.
What is the Difference Between Key Limes and Limes?
After having tested it several times I can tell you that without a doubt, there is a difference between regular limes (Persian limes) and key limes. Those limes you buy at the grocery store a typically bigger and greener than the smaller, and often yellower, key lime.
Key Lime Pie Recipe
There are three important parts to this recipe–the crust, the pie filling, and the whipped topping. Since Key Lime Pie is named after key limes (smaller than golf balls with yellow-green skin), make sure to use key lime juice for the distinctive flavor.
Crust Ingredients (full recipe below)
- Graham cracker crumbs–Can’t find graham cracker crumbs? You can always make your own crumbs by adding graham crackers into a storage bag and crushing them with a rolling pin.
- Granulated sugar
Pie Filling Ingredients
- Sweetened condensed milk
- Egg yolks
- Key lime juice–You can find bottles of key lime juice next to lime juice at the grocery store. If you stick with regular lime juice, the pie will not turn out as flavorful.
- Lime zest
Whipped Topping Ingredients
- Heavy whipping cream
- Confectioners’ sugar
How to Make the Crust
You may have noticed, I have a LOT of crust in this pie. You could use less, of course, but over the years I have heard that it’s something people love about my key lime pie!
If possible, make your own crust. The store-bought crusts are okay, but they just aren’t up to par with the homemade ones. To make the graham cracker crust, you could buy the graham cracker crumbs or crush about 10 graham crackers.
If you have to crush your own crackers, add them to a food processor and process until you have a fine crumb. You could also use a rolling pin to roll over the cookies that are in sealed plastic baggies to get them into fine crumbs. A hammer also works, but just gentle taps!
Combine the crushed crackers, granulated sugar, and melted butter in a medium bowl until the mixture is combined. When mixing together the ingredients (with a fork), make sure every single graham cracker crumb is coated in butter. The butter acts as the binding agent, so when you see recipes that have piles of graham crackers left on the plate, it is usually because they were not coated with butter.
Press the crust into a prepared 8-inch pie dish using your hand or the bottom of a glass to get the crust flattened across the bottom of the pan. Bake for about 15 minutes while you prepare the key lime pie filling.
How to Make the Key Lime Pie Filling
This filling is where all that key lime flavor is. I even added a little zest of lime to give it a little boost. To make the filling, use a medium bowl to stir and combine the condensed milk, whipped egg yolks, key lime juice, and lime zest.
Pour the mixture into the baked pie crust, and put the pie back in the oven to bake for 20-25 minutes. The internal temperature of the filling should be 145°F when done baking. Chill the pie in the refrigerator for at least 30 minutes. When the pie is almost completely chilled, make the homemade whipped topping.
How to Make Homemade Whipped Cream
- Don’t aim for “stiff peaks”. You want the whipped cream to keep its shape and be soft, billowing peaks. If by chance you OVERBEAT the whipped cream (I have done this and cried!) fixing it is actually very easy. Simply add in more fresh heavy whipping cream and whisk by hand. My life was changed when I found that out!
- Wait until peaks start to form before adding in the confectioners’ sugar. I much prefer confectioners sugar in this recipe, as it dissolves entirely and leaves a smooth texture. If you choose to use granulated sugar be sure to add it immediately at the beginning and whip it with the cream.
- Homemade whipped cream is best used immediately, but it can be stored for up to 10 hours if needed. After that, it may start to separate.
Top the chilled Key Lime Pie with the whipped cream and serve! If you would rather top this pie with a meringue topping, just use the meringue recipe in my Lemon Meringue Pie. Store the pie in the refrigerator, loosely covered with aluminum foil, for up to three days.
To freeze Key Lime Pie, freeze it without the added whipped topping. Place the pie in the freezer for a couple of hours before double wrapping it tightly in plastic wrap. Keep it in a heavy-duty freezer bag. Remember to label and date the wrapping; the pie will last for up to a month in the freezer. Thaw the pie in the refrigerator.
Looking for More Pie Recipes?
GRAHAM CRACKER CRUST
- 1 1/2 cups (about 10 crackers) graham cracker crumbs
- 1/4 cup granulated sugar
- 6 tablespoons melted butter
KEY LIME PIE FILLING
- 1 can (14 ounces) sweetened condensed milk
- 3 large egg yolks, whipped
- ¾ cup key lime juice, fresh is best
- 1 teaspoon key lime zest
- 1 pint (454g) heavy whipping cream
- 1/4 cup (31g) confectioners' sugar
Preheat oven to 325°F and grease an 8-inch pie pan.
In a medium bowl combine the graham cracker crumbs, sugar, and 4 tablespoons of the butter.
Using a fork, mix well. You want every crumb coated in the butter as this will be the glue that holds it together.
Pour the graham cracker crumbs into the prepared 8-inch pie dish. Pat them flat with your hand and then use a kitchen glass to press flatter. Start at the center and work out to the sides. You can go as far up the sides as you would like.
Bake the crust for 15 minutes.
KEY LIME PIE FILLING
While the crust is baking, add the condensed milk, egg yolks, key lime juice, and zest to a medium bowl. Stir to combine.
Pour mixture into the baked crust.
Bake for 20-25 minutes. The pie is done when you see the tiny surface bubbles start to pop, or the internal temperature is 145°F.
As soon as the pie comes to room temperature, chill in the refrigerator for at least 30 minutes.
When the pie is almost done chilling, add heavy cream to a mixing bowl. Start mixing at the lowest speed, and then gradually increase speed to medium until the cream starts to get thicker. (The gradual progression prevents you from spraying yourself with cream.)
When the cream starts to thicken, stop the mixer. Slowly add in the confectioners’ sugar and then resume mixing again, starting with low speed and increasing to medium speed and eventually moving to a high speed.
The cream will thicken and start to peak. Mix on high until the cream is thick and stiff. This happens quickly, the stage between soft and stiff peaks, so watch it closely.
Top the pie with whipped topping and serve!