This key lime pie comes together quickly and makes for the best pie! Key lime juice, sweetened condensed milk, sour cream, and lime zest all come together in a graham cracker crust for a simple dessert that has everything you love. It has the perfect flavor of lime, is creamy and delicious, and sits on the best crust.
If you love Key Lime Pie as much as I do, you’ll love how easy this recipe is to make. It comes together with just a few simple ingredients and a couple of easy steps. This pie is the perfect balance of tart and sweet and is fantastic to take to a party.
Why this Recipe Works
- Thick filling without eggs: The key reason this recipe works so well is that the acidity of the lime juice causes the proteins in the sweetened condensed milk to change shape, bind together, and create the thick custard filling. This process is called acid denaturation.
- The addition of sour cream: While the key lime juice and sweetened condensed milk react together to create the thickness we are looking for, it’s the sour cream that provides the perfect smooth texture.
- Short bake time: Because there are no eggs, this pie doesn’t need a long bake time to make it food safe. Rather, the short 10-minute bake helps to activate the chemical reaction.
- Watching for bubbles: The small bubbles at the end of the bake time are the signal that the chemical reaction has taken place and the pie will be the perfect consistency.
Key Lime Pie Ingredients
- Sweetened condensed milk: This, with the sour cream, forms the base of the pie. It is essential that you use sweetened condensed milk and not evaporated milk.
- Key limes and limes: In this recipe, we are using both key lime juice and the zest of limes. Both are key to getting the depth of flavor you want here. Key lime juice can be found with the lemon and lime juices in your grocery store. You can also purchase it on Amazon. I do not recommend using lime juice in place of key lime juice; regular lime juice is much too tart for this recipe.
- Sour cream: By using sour cream in this recipe, we are able to get a nice creamy texture without using eggs. It helps develop the custard filling while keeping the baking time short.
- Graham cracker crust: Part of what makes this the best key lime pie recipe is the crust. It calls for just graham crackers, sugar, and butter, and makes for the perfect sweet crust to balance the tartness of the filling.
How to Make Key Lime Pie
Here is a step-by-step overview of how this easy key lime pie recipe comes together. For the full recipe, including all measurements, scroll to the recipe card at the bottom of the post.
Make the Crust
Combine crust ingredients, which should resemble a wet sand mixture. Press the crumb mixture into a pie pan and bake it. You can read more about making a graham cracker pie crust here: Graham Cracker Crust.
Make the Filling
Whisk together the sweetened condensed milk, key lime juice, sour cream, and lime zest to make the filling while the crust is baking.
Build the Pie and Bake
Pour the key lime pie filling into the warm crust and bake just until bubbles start to form.
Chill and Serve
Allow to cool for 10 minutes, then refrigerate before serving. Garnish with whipped cream and lime slices if desired.
Tips and Tricks
- Remove the pie from the oven as soon as bubbles start to form. Watch it closely so it doesn’t overcook.
- Using sweetened condensed milk: Make sure to use sweetened condensed milk and NOT evaporated milk. Usually, when someone says their recipe didn’t set up, it is because they used the wrong ingredient. I would recommend sticking with Eagle brand; some of the off-brand products produce unsatisfactory results.
- Use key lime juice and not regular lime juice. Regular lime juice cannot replace the key lime juice here; it is too tart.
- Zesting limes: Lime zest is key to deepening the lime flavor in this pie. If you have never zested a lime, you want to use a zester and zest just the green skin, moving on to a different part of the lime when you hit the white rind.
Serving
This pie is best enjoyed the day it is made. Keep it in the refrigerator and top it with the most delicious whipped cream. I also have a stabilized homemade whipped cream if you prefer a version similar to Cool Whip.
Be sure the pie has completely cooled first; otherwise, the whipped cream will melt.
Storing and Freezing Key Lime Pie
Store your key lime pie in the refrigerator for up to three days. You can freeze the pie after it has set in the refrigerator. Store in the freezer for up to three months. When ready to eat, let thaw slightly in the refrigerator.
Other Key Lime Treats
If you can’t get enough of key lime, make sure to try these recipes:
- Key Lime Cake: A layer cake that is bursting with key lime flavor.
- Key Lime Cheesecake: Everything you love about this key lime pie in a cheesecake.
- Key Lime Martini: One of my very favorite martinis!
If you try this easy Key Lime Pie recipe or any of my other recipes, please leave a comment telling me what you think. I love hearing from you!
Recipe Video
Key Lime Pie
Ingredients
For Pie
- 2 1/3 cups sweetened condensed milk (two 14-ounce by weight cans, read more about sweetened condensed milk here)
- 3/4 cup key lime juice (do not use regular lime juice)
- 1/2 cup sour cream
- 2 tablespoons lime zest (about 3 limes)
For Crust
- 2 cups graham cracker crumbs 21 grams (about 14 sheets)
- 1/3 cup granulated sugar
- 8 tablespoons melted butter
Instructions
- Preheat your oven to 375 degrees Fahrenheit.
- While the oven is preheating, combine the ingredients for the pie crust. It should resemble a wet sand mixture. Press the crumb mixture into a 9-inch deep pie pan. Bake the crust for 8-10 minutes or until golden brown.2 cups graham cracker crumbs, 8 tablespoons melted butter, 1/3 cup granulated sugar
- Once the crust is done baking, lower the oven temperature to 350 degrees Fahrenheit.
- While the pie crust is baking, whisk together the ingredients for the filling. Pour the filling into the warm pie crust. Bake the pie for 10 minutes or until bubbles just begin to form at the top.2 1/3 cups sweetened condensed milk, 3/4 cup key lime juice, 1/2 cup sour cream, 2 tablespoons lime zest
- Remove the pie from the oven and transfer to a cooling rack. Allow the pie to cool for 10 minutes. Then chill it in the refrigerator for one hour before slicing.
Iris Saxon UK says
Hi Lisa, can’t get Key Limes in the UK. Only ordinary limes. Is there much difference? Iris
Hi Iris! There is a section within the post that describes the difference between the two. I also give my recommendation for a key lime juice in that section. I’m not sure if it is available in the UK but probably more likely than actual key limes.
Stephanie says
Could you use cinnamon graham crackers?
You certainly can, I’m not sure that is a flavor I would enjoy in this recipe.
Judith says
Do you zest the key limes, or zest Persian limes? I know you use the key limes for juice, but how about the zest? Thanks!
I use regular limes for the zest.