This keto key lime pie is sweet and creamy, with a tender crust and a rich lime custard filling. It’s just as delicious as the real deal, and will have your tastebuds dancing for joy.
Whip up a batch of my sugar free condensed milk and get baking today!
Keto pie lovers, rejoice! And add this sweet and tangy keto key lime pie to your baking list right away. It’s a classic and now it’s completely sugar free and grain free.
One might wonder what took me so long to create a low carb key lime pie recipe. After all, I have several recipes that use those tangy flavors, like keto key lime bars and key lime pound cake.
Let’s just say that I don’t like to release recipes into the world until they meet my standards. My late father adored key lime pie, and it was important to me to perfect a low carb version before I posted it.
Classic style recipe
This sugar free pie is made in the classic style, with a custard filling made with egg yolks, sweetened condensed milk, and lime juice. I very much wanted to stay true to the original.
This was tricky to get right, since sugar is one of the ingredients that helps traditional key lime pie set properly.
That’s why so many keto recipes rely on cream cheese to help set the filling. As tasty as that is, it’s more cheesecake than custard.
To get true keto key lime pie with my homemade condensed milk, I found that I needed to use another egg yolk to help it set.
Keto Graham Cracker Crust
Traditional key lime pie features a graham cracker crust, and many readers as me if they can use my keto graham crackers for this. And you certainly can do that, but it’s a lot of wasted effort, if you ask me.
Think about it: first you have to make the graham crackers, then crumble them in a food processor, measure them out, mix them into a crust, and bake them again.
Whereas you can simply take all the ingredients that make up the graham crackers, whisk them together, press them into a pan, and bake once. It’s so much easier and tastes exactly the same.
I shared some of this keto key lime pie with a neighbour and received a text later that said the pie was great and the crust was out of this world!
Tips for keto key lime pie
Once you have the sugar free condensed milk and crust ready to go, this pie is a snap to make. Here are my best tips for getting it right:
- Make the condensed milk. It needs to cool completely so make this in advance of the crust. You can even make it the day before and refrigerate it overnight. It will thicken a lot in the fridge but you can simply let it come to room temperature and it will loosen up again.
- Prep the crust. This is a modified version of my easy keto pie crust, with Swerve Brown and a touch of cinnamon to make it taste more like a graham cracker crust.
- Par-bake the crust. About 12 minutes in the oven will help the crust set nicely before you add the key lime filling.
- Beat the egg yolks. I gathered some great tips from this recipe on King Arthur Baking. Beating the yolks until they thicken helps set the pie and make the filling super creamy.
- Beat in the condensed milk. You want to beat this until the mixture increases in volume, which again makes the filling lusciously smooth and creamy.
- Bake the pie. I recommend covering it in foil for the first 30 minutes to keep the crust from over-browning.
- Chill the pie. Patience, friend! A good keto key lime pie needs to chill and set for at least 3 hours.
Frequently Asked Questions
Absolutely. Key limes are tiny and hard to squeeze for juice, so regular Persian limes will work just as well.
You can use different sweeteners in the crust and the filling but please bear in mind that only erythritol-based sweeteners will produce a crisp crust. And using some BochaSweet or allulose in the condensed milk is best to avoid recrystallization.
Read more about different sweeteners work in my Guide to Keto Sweeteners.
Yes, you can make this recipe without dairy. For the condensed milk, use coconut cream to replace the heavy whipping cream. And use coconut oil or other non-dairy butter in the crust.
Because it’s custard based, the keto key lime pie should be refrigerated at all times. It will last up to 5 days in the fridge.
This is not a great recipe for freezing, as the filling may change consistency.
More delicious keto pie recipes
- Keto Peanut Butter Pie
- Sugar Free Pecan Pie
- Keto Pumpkin Cream Pie
- Lemon Sour Cream Pie
- Keto Coconut Cream Pie
- Sky High Chocolate Mousse Pie
Keto Key Lime Pie Recipe
- Preheat the oven to 325F.
- In a large bowl, whisk together the almond flour, brown sugar substitute, cinnamon, and salt, breaking up the clumps. Stir in the butter until well combined.
- Press firmly into the bottom and up the sides of a glass or ceramic pie plate. Crimp the edges decoratively.
- Bake 12 minutes, until just beginning to brown around the edges. Remove and let cool completely.
- In a large bowl, beat the egg yolks with the lime zest for 3 to 4 minutes, until thickened and paler in color.
- Add the condensed milk and beat for another 4 minutes, until the mixture has increased in volume. Beat in the lime juice and powdered sweetener.
- Pour the mixture into the cooled pie crust. Cover the pie with foil (shiny side up) and return the pie to the oven at 325F.
- Bake 30 minutes, then remove the foil and bake uncovered for another 10 minutes or so. The filling should be set around the edges but still a little jiggly in the center.
- Remove and let cool completely, then refrigerate 2 to 3 hours to set.