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This cool and creamy keto key lime pie is the perfect treat for a hot day! I’ll show you how to make a sugar-free key lime pie with simple ingredients and just a few minutes of prep time.
If you like the flavor of keto lemon meringue pie, you’ll love this sweet and tart alternative. I also have a no bake version in the Wholesome Yum app.
A super smooth low carb key lime pie needs a sweetener that dissolves easily! That’s why I use Besti Powdered Monk Fruit Allulose Blend for this dessert. Since it measures and tastes like sugar, nobody can tell that this pie is keto friendly… and with a fine consistency that dissolves completely, every bite stays creamy. Pair it with a buttery crust using Wholesome Yum Almond Flour, and you’ll never miss conventional key lime pie again!
Is Key Lime Pie Keto?
Most key lime pie recipes are not keto friendly, since they contain refined sugar, conventional sweetened condensed milk, and a traditional graham cracker crust with gluten. However, it’s easy to swap these ingredients to make a recipe for sugar-free key lime pie that tastes just as delicious!
Why You’ll Love This Keto Key Lime Pie Recipe
- Sweet and tangy flavor
- Cool, creamy texture
- Uses basic keto ingredients
- Low carb and gluten-free
- Just 5 grams net carbohydrates per slice
- Mouthwatering summer dessert!
Ingredients You’ll Need
This section explains how to choose the best ingredients for sugar-free key lime pie, what each one does in the recipe, and substitution options. For measurements, see the recipe card below.
- Almond Flour Pie Crust – You can also use coconut flour pie crust for a nut-free variation.
- Sugar-Free Sweetened Condensed Milk – Helps make the creamy consistency, and it’s easy to make yourself! You may be able to make a dairy-free version if you need to by using coconut cream or full-fat coconut milk instead of heavy cream.
- Egg Yolks – Help the key lime pie filling “set” and adds to the rich and smooth mouthfeel.
- Besti Powdered Monk Fruit Allulose Blend – This one dissolves the best and tastes the most like sugar, all with 0g net carbs. You can use other powdered sugar substitutes, but many other brands have erythritol in them and have a tendency to crystallize when storing, so the texture may be gritty if not using Besti.
- Key Lime Juice – Get a bottled version like this for convenience, or squeeze your own limes. You can use regular or key limes for this juice.
- Lime Zest – Adds extra lime flavor with minimal extra carbs.
- Sea Salt – Balances the tart and tangy sweetness.
- Optional Garnishes – Thinly sliced fresh limes and sugar-free whipped cream.
How To Make Sugar-Free Key Lime Pie
This section shows how to make keto friendly key lime pie, with step-by-step photos and details about the technique, to help you visualize it. For full instructions, including amounts and temperatures, see the recipe card below.
- Make condensed milk. Prepare the sugar-free condensed milk (be sure to double the recipe) and set aside to cool.
- Make the crust. Prepare the almond flour pie crust and set aside to cool.
- Make filling base. In a medium bowl, use a mixer or whisk to combine condensed milk and egg yolks until smooth.
- Add lime. Add key lime juice and lime zest, whisking until smooth. Taste the filling and whisk in Besti, if desired, until it reaches your desired sweetness.
- Pour. Pour filling into the cooled crust. Smooth the top and cover edges with foil or a pie shield.
- Bake. Bake keto key lime pie for 15 minutes.
TIP: Pie will still look runny.
The filling will not completely set until it sits in the fridge for 3-4 hours.
- Chill. Cool for 30 minutes on the counter, then refrigerate until set.
- Garnish. Top with lime zest, keto whipped cream, and lime (or key lime) slices.
Tips For The Best Keto Key Lime Pie
Make and serve this pie easily with a few key tips:
- Don’t skip the chilling time. Otherwise the pie will be too runny and hard to cut.
- Make clean slices. Use a sharp knife to cut the pie, wiping it clean between slices.
- Serve it soon. For best results, serve the pie within 24 hours of making it. The crust can be made ahead, but once the filling is added, the crust has the best texture within the first 24 hours after it sets.
- Store: Keep leftovers covered in the fridge for 1-2 days.
- Freeze: To freeze pie, divide into slices and freeze individually until solid. Then wrap tightly for long term freezer storage for up to 1 month.
More Keto Pie Recipes
Try these cool and summery pies next — all with no sugar whatsoever.
Tools To Make Sugar-Free Key Lime Pie
- Citrus Juicer – Helps squeeze limes super fast for the freshest flavor.
- 9-Inch Pie Pan – My go-to pan for this pie.
- Pie Shield – Keeps crust from browning too fast.
Low Carb Key Lime Pie Recipe
Keto Key Lime Pie
This keto key lime pie recipe has a sweet creamy filling and buttery crust, just like the real deal. Nobody can tell it's a sugar-free key lime pie!
Recipe VideoTap on the image below to watch the video.
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Tap underlined ingredients to see where to get them. Please turn Safari reader mode OFF to view ingredients.
Tap on the times in the instructions below to start a kitchen timer while you cook.
Make the sugar-free sweetened condensed milk according to the instructions here. Set aside to cool to room temperature.
Preheat the oven to 350 degrees F (176 degrees C).
Make the keto pie crust according to the instructions here. Set aside to cool. Leave the oven on at 350 degrees F (or preheat again before step 6).
Meanwhile, in a medium bowl, whisk together the condensed milk, egg yolks, and salt, until smooth.
Whisk in the lime juice and lime zest, until smooth.
Taste the filling to see if it’s sweet enough to your liking. If not, whisk in Besti Powdered, until dissolved, to achieve your desired sweetness.
Pour the filling mixture into the cooled crust and smooth the top. Cover the edges of the crust with foil or a pie shield.
Bake the keto key lime pie for 15 minutes. The filling will still be runny and will not set at this step – this is normal.
Remove the pie from the oven. Cool for 30 minutes on the counter, then refrigerate for at least 3-4 hours, until set. Serve cold or at room temperature.
Last Step: Leave A Rating!
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Serving size: 1 slice, or 1/12 entire recipe
Nutrition facts are provided as a courtesy. Have questions about calculations or why you got a different result? Please see our nutrition policy.
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When I took it out of the oven the pie had split and had a curdled texture. Any idea why it would have done that? I followed your recipe for both the condensed milk and the pie using your besti powedered sugar. My only thought was that the condensed milk was slightly over cooked. Any ideas?
Wholesome Yum D0
Hi Alyssa, Sorry this recipe didn’t turn out as expected. It does sound like the pie was over cooked. I would try cooking for a shorter amount of time next time.
This was absolutely the best! The flavor was incredible – you cannot tell it is low carb it tastes so rich. I followed the recipe completely – from the almond pie crust (totally yummy), the sugar-free sweetened condensed milk and the pie. OMG. I cannot say enough good about this one. Love love love it!
I made this on a Sunday & ate a slice today (Monday). I used the almond flour pie crust. The taste was really good, but the filling was more dense than I have had in the past for other (non-keto) pies. I’m not sure if I did something wrong to have this happen. It was nice to have an alternative to the high-carb/sugar pie recipe. I juiced about 24 key limes, and added 1/2 of a regular lime to get the full amount needed.
I am not certain I will make this again due to the time involved, but it is a good recipe (despite the heaviness of the filling).
I guess I cooked the condensed milk too long it tastes like caramel!! Will it ever thicken now??
Wholesome Yum D0
Hi Julia, It sounds like you probably cooked the sauce too long and it turned into keto caramel sauce.
I made this keto Key Lime pie for Fathers Day today and while the taste was great, the pie filling did not set properly and was instead more like a runny pudding. I followed the recipe to the letter, let it set in the refrigerator overnight but it never set in the middle. The condensed milk turned out perfect, I used fresh key lime juice and zest, pie crust was perfect, but the filling – not so… Any suggestions on why the filling didn’t set? Thank you.
Wholesome Yum D0
Hi Brenda, Did you use Besti Powdered Monkfruit Sweetener in your pie?
Brenda G. Rauscher0
No. I used a monk fruit & allulose blend (powder) from Impact Products that I had on hand.
Wholesome Yum D0
Hi Brenda, That may be one of the reasons, I only use Besti Sweeteners because I know they give the best results. You may also try baking a little bit longer to get the pie to set better.
What a great keto pie! YUM!
Come summer all I want, is all things tart! Lemon & lime desserts are the best!! This is perfect, creamy, & so darn good!
This is seriously an amazing sugar-free dessert!! So good and delicious!