This authentic key lime pie starts with a homemade graham cracker crust, then a creamy sweet and tart filling, and fluffy toasted meringue. This is a cool and refreshing dessert, and perfect for summer!
Jump straight to the recipe!
🥧A bright, citrusy dessert
Key lime pie is traditionally made with key limes, which are tropically grown and yellow when ripe. They also have more seeds than a regular lime. Here is a a description of how key lime vs lime, if you want more info.
If you can get your hands on key limes, then for sure, use them in this recipe. For anyone that can only find the regular green limes, then use those. That's all I could find, and this pie turned out with the perfect balance of lime flavour.
For more citrus desserts, try Italian Lemon Cream Cake, Lemon Meringue Cheesecake, or Lemon Pound Cake Loaf.
🥘Ingredients
Ingredient notes
- Limes - Key limes or regular limes both work in this recipe.
- Whole milk - 2% milk can be substituted. I don't suggest a lighter fat milk than that though.
- Unsalted butter - Salted butter can be used instead. Just omit the extra added salt.
🔪Instructions
Graham cracker crust
The crust is a graham cracker crust, which I think goes so well with this pie. To make it, preheat oven to 350°F (180°C). Grease a 9" pie dish (I like to use butter), and set it aside.
In a medium bowl, combine graham cracker crumbs, brown sugar, and melted butter. Stir together until the butter has been mixed into the other ingredients fully. Pour crust ingredients into the pie dish, and push the crust into the bottom and up the sides of the dish. Bake for 10 minutes and let cool on a wire rack while you make the filling.
You could stop here and refrigerate the crust until the next day, or carry on making the pie.
Key lime filling
To make the filling, combine sugar, cornstarch, and salt in a medium saucepan. Stir to combine and then mix in heavy whipping cream, milk, egg yolks, and lime juice. Over medium heat, whisk to combine.
Bring the mixture to a boil, whisking constantly. Whisk for another couple of minutes until mixture thickens and coats the back of a spoon.
Remove from heat and immediately add cold butter, lime zest, and vanilla. Whisk until combined and mixture has cooled. Allow filling to cool slightly at room temperature for about 15 minutes, and then pour it into the crust and smooth into an even layer.
Meringue topping
To make the meringue topping, preheat oven to 425°F (220°C). Beat egg whites in a large bowl until frothy. Add cream of tartar and continue beating until stiff peaks form.
Add sugar in, a tablespoon at a time, until meringue is stiff and glossy. Spoon the meringue over the filling and spread it out so it touches the pie dish. This will prevent the meringue from shrinking. Rough it up a little so there are a lot of ridges that will brown nicely when toasting it.
Bake for 5-7 minutes, or until meringue is golden brown. You could also use a blow torch to toast the topping. Store in the refrigerator for up to 4 days, covered.
For more step by step pictures, view the web story for this key lime pie recipe!
✔️Expert tips
- Instead of a meringue topping, use a whipped cream topping instead.
- Use freshly squeezed lemons for best taste. Plus, you need the fresh zest for this recipe.
- Zest the lemons before squeezing their juices out. It is not easy to zest a lemon afterwards.
- Feel free to use store bought graham cracker crust if you want.
💭FAQ's
The crust can be made a day ahead and refrigerated. The rest of the pie should be made the same day, because the crust will get soggy as it sits. It still tastes good though!
Meringue topping is simply egg whites beaten with sugar and cream of tartar.
You can toast your meringue in the oven, or use a blow torch. Both work very well.
🔖Related recipes
📋 Recipe
Authentic Key Lime Pie {without condensed milk}
Equipment
- One 9 inch pie dish
Ingredients
Crust
- 1 ½ cups graham cracker crumbs
- 2 tablespoons brown sugar packed
- 4 tablespoons unsalted butter melted
Key Lime Filling
- 1 cup granulated sugar
- 6 tablespoons cornstarch
- ¼ teaspoon salt
- 1 cup heavy whipping cream
- 1 cup whole milk
- 4 large egg yolks
- ¼ cup lime juice
- 3 tablespoons unsalted butter cold
- ½ teaspoon vanilla extract
- 1 tablespoon lime zest
Meringue Topping
- 4 large egg whites
- 5 tablespoons granulated sugar
- ¼ teaspoon cream of tartar
Instructions
Crust
- Preheat the oven to 350°F (180°C). Grease a 9" pie dish.
- In a medium bowl, combine graham cracker crumbs, brown sugar, and melted butter. Stir together until the butter has been mixed into the other ingredients fully.
- Pour crust ingredients into prepared pie dish, and push the crust into the bottom and up the sides of the dish. Bake for 10 minutes and let cool on a wire rack.
Key Lime Filling
- Combine sugar, cornstarch, and salt in a medium saucepan. Stir to combine and then mix in heavy whipping cream, milk, egg yolks, and lime juice. Over medium heat, whisk to combine.
- Bring the mixture to a boil, whisking constantly. Whisk for another couple of minutes until mixture thickens and coats the back of a spoon.
- Remove from heat and immediately add cold butter, lime zest, and vanilla. Whisk until combined. Allow filling to cool slightly at room temperature for about 15 minutes, and then pour it into the crust and smooth into an even layer.
Meringue Topping
- Preheat oven to 425°F (220°C). Beat egg whites in a large bowl until frothy. Add cream of tartar and continue beating until stiff peaks form.
- Add sugar in, a tablespoon at a time, until meringue is stiff and glossy. Spoon the meringue over the filling and spread it out so it touches the pie dish. This will prevent the meringue from shrinking.
- Bake for 5-7 minutes, or until meringue is golden brown. Store in the refrigerator for up to 4 days.
Notes
- Instead of a meringue topping, use a whipped cream topping instead.
- Key limes or regular limes both work in this recipe.
- Use freshly squeezed lemons for best taste. Plus, you need the fresh zest for this recipe.
- Zest the lemons before squeezing their juices out. It is not easy to zest a lemon afterwards.
- 2% milk can be substituted for whole milk. I don't suggest a lighter fat milk than that though.
- Feel free to use store bought graham cracker crust if you want.
- Salted butter can be substituted for unsalted butter in the recipe. Just omit the extra added salt.
Evangelina
If I use whipped topping instead of meringue, does it need to be baked?
Nina
Hi Evangelina! Yes the filling still needs to be baked. You can put the whipped topping on it after baking and cooling the pie.
Lorraine M Carolan
DDoes the filling only need 5-7 minutes top bake?
Seems like not very much
Nina
Hi Lorraine! The filling gets cooked in a saucepan over medium heat until boiling. Then it takes a few more minutes to thicken. The filling gets spooned into the pie crust, and topped with meringue.
AmyR
Add this one to the list of things I'm amazed that I could actually make, like when I made french onion soup. I thought I had sweetened condensed milk. I didn't even have the cream, so I had to use all whole milk and still it came out great. Right now I was just making the filling part of this recipe. I used over a quarter of a cup of green lime juice to begin with and I think I would have preferred more of a lime flavor. I squeezed another green lime in after I tasted it. Do you think it will work as a lime curd as is? or should I still bake it? Thank you.
Nina
Hi Amy, sorry for the late reply. I hope it worked out for you! Adding extra juice may make the curd more runny. The pie goes into the oven to toast the meringue only, so make sure it has thickened before continuing with the recipe.