Keto Key Lime Pie

Did You Know Most “Healthy” Pies Are Still Hiding Sugar?

Here’s a fact that might surprise you: the average slice of traditional key lime pie contains over 35 grams of sugar and nearly 50 grams of carbs. For anyone following a ketogenic diet, that’s practically a full day’s carb budget in a single dessert. So the question is, does that mean you have to give up one of the most beloved pies in American cuisine? Absolutely not.

This keto key lime pie recipe gives you everything you love about the classic: that bright, citrusy tang, the luscious creamy filling, and a buttery, crunchy crust without the sugar spike. Whether you’re a seasoned keto follower or just looking for a low-carb dessert that doesn’t taste like a compromise, this is the recipe you’ve been waiting for.

Let’s dive in.

Ingredients

Below is everything you need to make the best keto key lime pie from scratch. Each ingredient was chosen to keep the net carbs low while preserving authentic flavor and texture.

For the Almond Flour Crust:

• 1 ½ cups blanched almond flour
• 3 tablespoons unsalted butter, melted
• 2 tablespoons powdered erythritol (or monk fruit sweetener)
• ½ teaspoon vanilla extract
• Pinch of salt

For the Creamy Key Lime Filling:

• 3 large egg yolks
• 1 tablespoon key lime zest (about 6–8 key limes)
• ½ cup fresh key lime juice (bottled works too)
• 2 cans (14 oz each) full-fat coconut cream or heavy cream
• ⅓ cup powdered erythritol
• 1 teaspoon vanilla extract
• 2 teaspoons unflavored gelatin (for a firmer set)

For the Topping (Optional):

• 1 cup heavy whipping cream
• 2 tablespoons powdered sweetener
• ½ teaspoon vanilla extract
• Key lime slices for garnish

Substitution Notes:

• No almond flour? Use finely crushed pecans or sunflower seed flour for a nut-free version.
• Prefer a different sweetener? Allulose works beautifully and has zero cooling effect.
• Can’t find key limes? Regular Persian limes are a perfectly acceptable swap, just use slightly less juice as they’re more tart.

Timing

• Prep time: 20 minutes
• Cook time: 15 minutes (crust only)
• Chill time: 4 hours (or overnight for best results)
• Total time: approximately 4 hours 35 minutes

That’s roughly 20% less active hands-on time than the average traditional key lime pie recipe, which typically requires more steps for its condensed milk-based filling.

Step by Step Instructions

Step 1: Preheat and Prepare Your Pan

Preheat your oven to 350°F (175°C). Lightly grease a 9-inch pie dish with butter or coconut oil. If you want clean slices later, line the bottom with a round of parchment paper.

Pro tip: A glass pie dish distributes heat more evenly than metal, giving your crust a beautifully golden, even bake.

Step 2: Make the Almond Flour Crust

In a medium bowl, combine the almond flour, melted butter, powdered sweetener, vanilla, and salt. Mix until the texture resembles wet sand; it should hold together when pressed between your fingers.

Press the mixture firmly and evenly into the bottom and up the sides of your prepared dish. Use the flat bottom of a measuring cup to smooth it out. Bake for 12–15 minutes until the edges are golden. Let it cool completely before adding the filling.

Pro tip: Don’t rush the cooling. Adding warm filling to a warm crust is the number one reason keto pie crusts turn soggy.

Step 3: Zest and Juice Your Key Limes

Roll each lime firmly on the counter before cutting; this breaks down the cells and releases more juice. Zest first, then juice. You’ll need about 6–8 key limes for ½ cup of juice.

Pro tip: Strain your juice through a fine mesh sieve to catch seeds and pulp. This gives your easy keto key lime pie a silky-smooth filling.

Step 4: Bloom the Gelatin

Sprinkle the unflavored gelatin over 2 tablespoons of cold water in a small bowl. Let it sit for 5 minutes to bloom. This is what gives your best keto key lime pie a sliceable, firm texture without using condensed milk.

Step 5: Make the Filling

In a medium saucepan over medium-low heat, whisk together the egg yolks, lime zest, lime juice, coconut cream (or heavy cream), and powdered sweetener. Heat gently, don’t boil, stirring constantly for about 8–10 minutes until slightly thickened.

Remove from heat and whisk in the bloomed gelatin and vanilla extract until fully dissolved and smooth.

Pro tip: Keep the heat low and patient. Rushing this step on high heat can cause the eggs to scramble.

Step 6: Fill and Chill

Pour the filling through a fine mesh strainer into the cooled crust. Tap the dish gently on the counter to release any air bubbles. Cover loosely with plastic wrap (don’t let it touch the surface) and refrigerate for a minimum of 4 hours, or overnight.

Step 7: Whip the Topping and Serve

When ready to serve, beat the heavy whipping cream, powdered sweetener, and vanilla with a hand mixer until stiff peaks form. Pipe or spoon onto your chilled keto key lime pie and garnish with thin key lime slices.

Nutritional Information

The following values are per serving, based on 10 slices per pie (filling and crust, no whipped topping):

Note: Values are estimates and may vary based on specific brands and substitutions used.

Compared to a traditional slice of key lime pie, which averages 350–400 calories and 45–50g net carbs, this keto key lime pie recipe cuts net carbs by approximately 90% while keeping you firmly in ketosis. If you’re tracking macros, this guide to carbohydrates on keto is a handy reference.

Healthier Alternatives for the Recipe

This recipe is already low-carb and sugar-free, but here are a few tweaks to fit specific dietary needs:

Dairy-Free Version: Replace heavy cream with full-fat coconut cream and use coconut oil instead of butter in the crust. The coconut notes actually pair beautifully with the lime.

Higher Protein Version: Add 2 tablespoons of unflavored collagen peptides to the filling. It dissolves invisibly and adds roughly 9g of protein per tablespoon.

Nut-Free Version: Swap almond flour for sunflower seed flour in a 1:1 ratio. Add ½ teaspoon of baking soda to neutralize the natural green tint sunflower seeds develop when baked.

Lower Calorie Version: Use a lighter hand with the crust and skip the whipped topping. You can shave about 80 calories per slice without losing the core dessert experience.

Egg-Free Version: Skip the egg yolks and increase the gelatin to 3 teaspoons. The result is slightly less custardy but still delicious.

Serving Suggestions

This best keto key lime pie is impressive enough for a dinner party and easy enough for a weeknight treat. Here are a few ways to serve it:

Classic Slice: A clean wedge topped with piped whipped cream and a thin lime wheel. Simple, elegant, crowd-pleasing.

Mason Jar Style: Layer crumbled crust, filling, and whipped cream in small jars for individual no-bake parfaits, great for meal prep.

Frozen Pie: Freeze the finished pie for 2–3 hours for a semi-frozen, ice cream-like experience. Slice straight from the freezer with a warm knife.

Keto Dessert Board: Pair slices alongside keto chocolate truffles, berries, and dark chocolate for an impressive low-carb dessert spread for guests. Need more ideas? Browse our full collection of keto dessert recipes for inspiration.

Garnish Ideas: Toasted coconut flakes, a dusting of lime zest, or a few crushed macadamia nuts on top all add texture and visual appeal.

Common Mistakes to Avoid

1. Skipping the bloom step for gelatin. Sprinkling dry gelatin directly into warm liquid causes clumping. Always bloom it in cold water first for a smooth, lump-free filling.

2. Over-baking the almond flour crust. Almond flour burns faster than wheat flour. Pull the crust at golden, not brown, and remember it will continue to firm up as it cools.

3. Not chilling long enough. Many failed attempts at easy keto key lime pie come down to impatience. Four hours is the minimum; overnight is ideal. The filling needs time to fully set.

4. Using bottled lime juice exclusively. Fresh zest is non-negotiable for the best keto key lime pie flavor. The essential oils in the zest deliver the signature aromatic punch that juice alone cannot.

5. Adding hot filling to a warm crust. Both must be at room temperature or cooler before combining. This ensures the crust stays firm and the filling sets properly.

6. Skipping the strain. Straining your filling before pouring removes stray bits of zest and egg, resulting in a beautifully clean, professional texture.

Storing Tips for the Recipe

Refrigerator: Store leftover slices in an airtight container in the fridge for up to 5 days. Keep the whipped topping separate if possible, as it can weep and soften the filling.

Freezer: This keto key lime pie freezes exceptionally well. Wrap individual slices in plastic wrap, then place in a freezer-safe container. Frozen slices keep well for up to 2 months. Thaw overnight in the fridge.

Make-Ahead Tips: The crust can be baked up to 3 days ahead and stored at room temperature in the pie dish, covered loosely. The filling can be made a day in advance and poured into the chilled crust when ready.

Avoid: Storing whipped cream topping already applied if you plan to freeze, it doesn’t freeze well and will separate upon thawing.

Conclusion

This keto key lime pie delivers everything the classic does: tangy, creamy, and utterly satisfying with just 5g net carbs per slice. With an almond flour crust, a gelatin-set lime filling, and a fluffy whipped topping, it’s a show-stopping low-carb dessert anyone can make. Give this keto key lime pie recipe a try and make it your own.

Loved this recipe? Leave a comment below telling me how it turned out. I read every single one! You can also subscribe to Simply Keto Hub for new low carb recipes delivered straight to your inbox every week. And if you’re on a keto pie kick, don’t miss our equally irresistible keto pumpkin pie next.

Frequently Asked Questions

Keto Key Lime Pie

Recipe by LeeseCourse: DessertsCuisine: American

Servings

10

slices

Prep time

20

minutes

Cooking time

15

minutes

Total time

4

hours 

35

minutes

A creamy, tangy, sugar-free keto key lime pie with an almond flour crust and only 5g net carbs per slice. The best low carb dessert for any occasion.

Ingredients

• 1 1/2 cups blanched almond flour

• 3 tablespoons unsalted butter, melted

• 2 tablespoons powdered erythritol

• 1/2 teaspoon vanilla extract

• Pinch of salt

• 3 large egg yolks

• 1 tablespoon key lime zest

• 1/2 cup fresh key lime juice

• 2 cans (14 oz each) full-fat coconut cream or heavy cream

• 1/3 cup powdered erythritol

• 1 teaspoon vanilla extract

• 2 teaspoons unflavored gelatin

• 1 cup heavy whipping cream

• 2 tablespoons powdered sweetener

• Key lime slices for garnish

Directions

• Preheat and Prepare Your Pan:
  Preheat your oven to 350°F (175°C). Lightly grease a 9-inch pie dish with butter or coconut oil.
• Make the Almond Flour Crust:
  Combine almond flour, melted butter, powdered sweetener, vanilla, and salt. Press into a pie dish and bake for 12–15 minutes until golden. Cool completely.
• Zest and Juice Your Key Limes:
  Roll limes to release juice, then zest and juice 6–8 key limes for 1/2 cup of juice. Strain through a fine mesh sieve.
• Bloom the Gelatin:
  Sprinkle unflavored gelatin over 2 tablespoons of cold water. Let it sit for 5 minutes to bloom.
• Make the Filling:
  Whisk egg yolks, lime zest, lime juice, cream, and sweetener in a saucepan over medium-low heat for 8–10 minutes. Remove from heat and whisk in bloomed gelatin and vanilla.
• Fill and Chill:
  Strain filling into the cooled crust. Cover and refrigerate for at least 4 hours or overnight.
• Whip the Topping and Serve:
  Beat heavy cream, sweetener, and vanilla to stiff peaks. Pipe onto chilled pie and garnish with key lime slices.