Skip to content
KETOFOCUS.

Spooky treats, zero sugar — keto Halloween recipes. Trick or Treat →

Keto Key Lime Pie

Annie Lampella, Pharm.D. Recipe developer and pharmacist

Published Updated

21 ratings

Silky, tart keto key lime pie on a flaky, buttery crust that holds up perfectly, with 5.4g net carbs per slice. I use homemade sweetened condensed milk instead of cream cheese in the filling, and the difference is night and day.
  • 5.4gnet carbs
  • 7gprotein
  • 95minutes
  • 8servings
a whole lime pie in a white pie plate
a slice of silky cream pie on a small white plate with green lime zest sprinkled around
a slice of pie cut out of the whole pie with dollops of whipped cream around and limes tossed around
1 of 3
Jump to recipe

This post may contain affiliate links. See my disclosure policy.

I always have a few desserts ready for holidays, summer potlucks, and those nights when someone says "what's for dessert" and I want to hand them something that ends the conversation. This is that dessert. Just like my peanut butter pie or my chocolate cream pie, it disappears fast and nobody asks if it's keto.

Most low carb key lime pie recipes use cream cheese to thicken the filling. I get why (it's easier), but it doesn't taste right. You end up with something closer to a cheesecake than the real thing. I chose to make my own sugar free sweetened condensed milk instead, and that one decision changes everything. The filling comes out smooth, tart, and silky, exactly like the version I grew up eating.

close up of the flaky pie crust on a key lime pie

The condensed milk takes about 30 minutes to simmer, plus a couple hours to chill, but I make it a day or two ahead so the actual pie assembly is fast. Three ingredients: butter, powdered sweetener, and heavy cream. If you use allulose instead of an erythritol-based sweetener, it won't crystallize, which I learned after testing both side by side. Allulose stays smooth. Erythritol works but can get a slight crunch if it doesn't fully dissolve.

For the crust, I use my flaky keto pie crust. It's almond flour-based with a little coconut flour and xanthan gum, and it holds up under a wet filling without getting soggy. I blind bake it at 350 for 8 minutes, then drop the temp to 325 before the filling goes in.

The filling itself is three steps: whisk yolks with lime zest for a couple minutes (this pulls out more color and flavor), fold in the condensed milk, then slowly drizzle in the lime juice. And I mean slowly. If you pour the juice in too fast, it curdles. I drizzle it in while whisking and then let the whole thing sit for 30 minutes before it goes into the crust. By that point it's already starting to thicken from the acid reacting with the egg yolks.

The recipe card calls for 2-3 hours in the refrigerator, or until set. Start checking at 2 hours and give it closer to 3 if the center is still soft. Overnight is fine if you make the pie ahead.

I bring this to every summer gathering and it works alongside my coconut cream pie, strawberry pie, or banana cream pie when I want a full dessert spread. The tart-sweet balance is the kind of thing that makes people go quiet mid-bite, which is always a good sign.

Key limes vs. regular limes

Key limes are smaller than the regular Persian limes you see at every grocery store. They tend to taste more tart and aromatic, have more seeds, and can look slightly yellow. I’ve made this with both, and the flavor difference is subtle enough that I reach for regular limes most of the time. They’re easier to juice, easier to find, and the filling tastes great either way. If you can get your hands on the real ones, go for it, but don’t let that stop you from making this recipe.

Low-carb graham cracker crust option

I used my flaky pastry crust for this pie, but a keto graham cracker crust works well too. The texture is close to real graham crackers, especially if you add graham cracker flavoring drops. I use the same crust base from my mini cheesecakes. Either crust pairs well with the tart filling.

a slice of key lime pie on a white plate with a dollop of whipped cream and lime slice on top

How to make a meringue topping

I went with whipped cream on top, but you can do a meringue instead. For a sugar free meringue topping, I’d follow the method from this lemon meringue pie. I haven’t perfected my own meringue recipe yet, but that one works well on this filling.

close up of the flaky pie crust on a key lime pie

Make ahead tips

  • Sugar free sweetened condensed milk: I make this days ahead. It keeps in the fridge for 2-3 weeks, so I usually have a jar ready to go. It stays fresh as long as the heavy cream you used.
  • Pie crust: The dough can sit in the fridge unbaked for 3-4 days, or I freeze it for up to a month. If I bake it ahead, the baked crust holds for 1-2 days covered in the fridge.
  • Assembled pie: Once baked, I keep it in the fridge for up to 3 days before topping and serving. I always wait to add the whipped cream until the day I’m serving it.

How to store this pie

I keep this pie covered loosely with plastic wrap in the fridge for 3-4 days. The filling holds its texture well, but the whipped cream starts to deflate after a day, so I always add the whipped cream right before serving. If I’m bringing it somewhere, I transport it without the topping and whip the cream on site.

How to make this pie

I prep this in three stages, and the order matters. The condensed milk goes first because it needs at least 2 hours in the fridge (overnight is better). Then the filling, then the crust while the filling sits and thickens.

a slice of pie sits in the corner with a slice out of a pie in the pie plate with the rest of the pie

Key ingredients

  • Sugar free sweetened condensed milk: I make my own with just butter, powdered sweetener, and heavy cream. Thirty minutes of simmering, then it chills. I prep it days ahead because it keeps for 2-3 weeks in the fridge. This is what separates the filling from those cream cheese versions.
  • Egg yolks: The acid from the lime juice reacts with the egg yolks to thicken and set the filling as it bakes and cools. Chemistry, not gelatin.
  • Lime zest and lime juice: I add the zest first and whisk it with the yolks for 2 minutes to pull out extra flavor and color without adding carbs from extra juice. Then the juice goes in slowly, or it curdles.
  • Low carb pie crust: I use my flaky pie crust for this. It uses almond flour, coconut flour, xanthan gum, salt, cold butter, cream cheese, egg, and rice vinegar or apple cider vinegar. It blind bakes cleanly and holds up under a wet filling.
Discover more keto recipes on our channel Hundreds of keto recipe videos, with step by step instructions and the tips that make keto easy.
KetoFocus
The recipe

Keto Key Lime Pie

Print Pin
Prep 45 min Cook 50 min Total 95 min Serves 8

Ingredients

Servings 8

Keto Sweetened Condensed Milk Ingredients

Key Lime Pie Filling Ingredients

Keto Pie Crust Ingredients

Keto Whipped Cream Ingredients

Step by Step Instructions

  1. Make sugar free sweetened condensed milk

    To a medium saucepan, add butter, powdered sugar free sweetener and heavy cream. Bring to boil over medium heat. Reduce heat and let simmer for 30 minutes to thicken. Remove from heat and pour into a mason jar or similar container. Let cool at room temperature for about 30 minutes before transferring in the refrigerator for 2 hours.

    For this step

    • Butter
    • Powdered sugar free sweetener
    • Heavy whipping cream
    holding a spoon of thicken condensed milk above a sauce pan with more sweetened condensed milk

  2. Prepare key lime filling: whisk yolks with zest

    In a medium glass bowl, whisk together lime zest with egg yolks. Whisk for about 2 minutes. Add sweetened condensed milk prepared earlier and stir until smooth.

    For this step

    • Lime zest
    • Egg yolks
    • Keto sweetened condensed milk (prepared from step 1)
    a whisk sitting in a bowl of whisked egg yolks and lime zest

  3. Prepare key lime filling: add lime juice

    Stirring by hand with a whisk, very slowly stir lime juice into the filling mixture. Set aside for 30 minutes to thicken slightly. Move onto the pie crust.

    For this step

    • Fresh lime juice
    light green pie filling in a clear bowl with a whisk sitting above

  4. Prepare the pie crust

    To a food processor, pulse together almond flour, coconut flour, xanthan gum and salt. Add in cubed butter, cream cheese, egg and vinegar. Pulse until just combined.

    For this step

    • Almond flour
    • Coconut flour
    • Xanthan gum
    • Salt
    • Butter (cubed & chilled)
    • Cream cheese (softened)
    • Egg
    • Vinegar
    pie dough mixed in a food processor

  5. Roll out pie crust and blind bake

    Roll out pie crust in between two sheets of parchment paper until the crust is a large circle about 1/8-1/4 inch thick. Refrigerate dough for 15 minutes. Remove the top layer of parchment paper and place pie plate upside down over the dough. Slide a hand under the bottom layer of parchment paper, place other hand on top of pie plate and flip over. Remove the parchment paper and press the pie dough into the pie pan. Bake at 350 degrees for 8 minutes. Lower heat to 325 degrees and let cool for about 20 minutes.

    an unbaked pie in a pie plate

  6. Assemble the pie

    Pour lime filling into the cooled pie crust. Bake at 325 degrees for 15-20 minutes, until edges are slightly set but the center still jiggles like jello. Refrigerate for 2-3 hours or until set.

    a baked but not set key lime pie on a towel

  7. Make sugar free whipped cream

    In a small bowl, add heavy cream and powdered sweetener. Beat with an electric mixer until stiff peaks form. Top on key lime pie. Top pie with additional lime zest if desired.

    For this step

    • Heavy cream
    • Powdered sugar free sweetener
    piping whipped cream on the edges of a lime pie

Nutrition

Per serving: 1 slice

Calories
578
Fat
55g
Protein
7g
Total carbs
7.9g
Net carbs
5.4g

Nutrition is an estimate calculated from the ingredients listed. Brands vary, so check labels if you track closely.

Frequently Asked Questions

Can I make the condensed milk dairy-free with coconut cream?

I've tested coconut cream as a swap and it works, but it's more finicky. Keep the heat lower than you would with heavy cream and don't rush it, or it separates on you. It takes an extra 5-10 minutes to reduce properly. The coconut flavor does come through, and it actually pairs well with the lime. I make it this way for my husband when he's avoiding dairy.

Why does the filling look wobbly when it comes out of the oven?

It's supposed to look wobbly. I pull mine when the edges are slightly set but the center still jiggles like jello. If you bake it until the center is firm, the texture will be off once it chills. The filling continues to set in the refrigerator, so trust the jiggle.

How long does this pie need to chill before serving?

The recipe card calls for 2-3 hours in the refrigerator, or until set. Start checking at 2 hours and give it the full 3 hours if the center still feels soft. Overnight is fine if you make the pie ahead.

Can I freeze this pie?

I haven't had great results freezing it. The filling texture changes once it thaws, and it loses that silky quality that makes this version different. I make it 2-3 days ahead and keep it in the fridge instead. If you need a freezer-friendly keto dessert, my peanut butter pie holds up better in the freezer.

Which sweetener works best in the condensed milk, allulose or erythritol?

I've made it with both. Allulose stays smooth and doesn't crystallize, so the condensed milk has a better texture overall. Erythritol works but can leave a slight crunch if it doesn't fully dissolve during the simmer. My go-to is powdered allulose. If you only have erythritol, make sure it's powdered (not granular) and give it the full 30 minutes to simmer.

Can I use a no-bake method instead?

I've seen no-bake versions that use gelatin or extra cream cheese to set the filling. I haven't gone that route with this recipe because the baking step is what gives the filling its signature texture. The egg yolks and lime juice react with heat to create that silky set. Without baking, you're relying on gelatin, and in my experience it ends up tasting more like a mousse than a pie.

Will lime juice concentrate work instead of fresh limes?

I've only tested this with fresh-squeezed juice. Concentrate tends to taste flat and overly sweet compared to fresh, and since the lime flavor is the whole point here, I wouldn't cut corners. Four regular limes give you the 1/2 cup of juice you need. It takes me about 5 minutes to juice them.

Is there a keto-friendly version of key lime pie?

Yes, this recipe is exactly that. One slice has 5.4g net carbs and 7.9g total carbs. I make a sugar free sweetened condensed milk from butter, powdered sweetener, and heavy cream, so the filling stays silky without added sugar. The crust uses almond and coconut flour instead of graham crackers, and it bakes up flaky enough that nobody asks if it's keto.

How to make a diabetic friendly key lime pie?

I make this pie without added sugar. The filling uses homemade sweetened condensed milk made with powdered sugar free sweetener, and the crust uses almond and coconut flour instead of graham crackers. One slice has 5.4g net carbs and 7.9g total carbs. The full nutrition breakdown is on the recipe card so you can decide whether it fits your own carb targets.

Browse by ingredient
Similar recipes

People who cooked Keto Key Lime Pie also made

1.5g NET CARBS
pretty fluted edges on a pie crust
Dessert Keto Pie Crust 77 min
2.1g NET CARBS
a slice of keto banana cream pie on a plate with a whole pie in the background
Dessert Keto Banana Cream Pie 45 min
5g NET CARBS
a slice of peanut butter cream pie on a white plate with chocolate and nuts on top
Dessert Keto Peanut Butter Pie 35 min
4.4g NET CARBS
sliding a fork into a cream pie
Dessert Keto Chocolate Cream Pie 40 min

Reviews

Tap to rate

4.8 from 21 ratings, 16 written

Made this recipe?

Replying to Jewelie Dee

Your rating

Tiffany Z.

The xanthan gum in the crust is doing something, mine held together clean under a fork instead of crumbling the way my almond flour crusts usually do. SO good, and it actually tastes like key lime pie!

Reply

Amber

Whisking the zest into the yolks before the juice goes in, the color shifts to this deep yellow that I didn’t expect. First pie I’ve made and it actually cut cleanly. Crust is a little bland on its own but doesn’t matter once you hit the filling.

Reply

Annie Lampella

Amber, that color shift is why I whisk the zest so long. Nice work getting a clean slice!

Reply

Elaine

Good tart-to-sweet ratio. Crust needed a few extra minutes but the filling set up perfectly.

Reply

Annie Lampella

I’m so glad the balance worked for you, Elaine! Crusts run different depending on how thin you roll them, so a few extra minutes is a fine call.

Reply

Nate

is it ok to use regular limes? I can never find key limes at my store.

Reply

Annie Lampella

Regular limes work. I reach for Persian limes whenever key limes aren’t around, and four of them get you that 1/2 cup. The flavor is slightly less tart but the filling sets up the same.

Reply

Jason

grabbing limes after work, trying this tonight

Reply

Annie Lampella

Jason, the recipe card calls for 2-3 hours in the fridge after it bakes, or until set. Start checking at 2 hours and give it closer to 3 if the center is still too soft to slice cleanly.

Reply

Lakshmi

ok the condensed milk filling is calling my name

Reply

Annie Lampella

Lakshmi, the condensed milk is the whole reason I rewrote this recipe. Use allulose if you can, it stays silky where erythritol can get a little grainy.

Reply

Morgan

The condensed milk filling really does change the texture. My sister brought a regular key lime pie the same week, so we ended up doing a side-by-side. Her take: more citrus punch, crust was the only tell. She doesn’t eat keto, so she had no reason to be nice about it.

Reply

Annie Lampella

Honest feedback from someone with no stake in the outcome is rare. I’ll own that the citrus punch is slightly different. Morgan, extra zest in the filling closes that gap.

Reply

Corinne

Making this for a Fourth of July cookout, so excited to finally try the sweetened condensed milk base instead of cream cheese. If I assemble the whole thing the night before, will the almond flour crust get soggy by the next day?

Reply

Annie Lampella

Night before is totally fine. I make mine 2-3 days ahead and it holds. Almond flour crust doesn’t go soggy the way regular pastry does, so you don’t have to rush anything.

Reply

Terri U.

Filling is as good as the comments say. Tart, sets up properly, not dense at all. The crust though. Almond flour just falls apart when you try to roll it, and mine went into the pan in about five pieces. Had to patch it back together. Still worth making, just don’t rush the crust.

Reply

Dani

Key lime pie was my summer thing for years, and I basically accepted it was off the menu when I went keto. Finally made this last weekend. The brightness from four fresh limes actually holds up to a real version. Overbaked my crust by a couple minutes so the edges got too dark, but that’s on me.

Reply

Annie Lampella

Edges go quick. I pull mine as soon as I see any color and let carryover finish it. A little dark on the rim doesn’t reach the filling though, so that stayed fine.

Reply

Yuki

I honestly thought making condensed milk from scratch was going to be a whole production and almost just bought a keto version somewhere, but it came together in one pan and the filling was so much silkier than I expected. Four stars because my crust cracked a little when I rolled it out, but the flavor had me going back for a second slice anyway.

Reply

Annie Lampella

Yuki, that silkiness is the whole reason I ditched cream cheese here. If the dough cracks while you roll it, let it warm up a few minutes and press the seams together. It bakes right over.

Reply

Melissa V.

Made this more times than I can count and the condensed milk filling still gets me every time I slice into it. Nothing with cream cheese comes close to that tartness.

Reply

Annie Lampella

Mine never makes it past day two. The tartness on that first slice gets me too.

Reply

Sarah R.

I had extra limes going soft on the counter and doubled the zest without really thinking about it. Figured worst case it would be too sharp. It was freaking perfect. The sweetened condensed milk base absorbs all that extra citrus and keeps the filling silky, so what you get is this punch of tart that almost stings in the best way. Three batches since. Doubling the zest every time.

Reply

Annie Lampella

Yeah, the condensed milk absorbs citrus without muting it. Cream cheese would’ve deadened all that tart. Three batches is convincing.

Reply

Aisha Thomas

Every other keto key lime pie I’ve tried uses cream cheese and it just ends up tasting like cheesecake in a crust (not in a good way). This one has actual tang from the lime juice and the condensed milk filling is smooth, not dense. I didn’t know keto pie could be this close to the real thing.

Reply

Annie Lampella

Cream cheese is the easy shortcut. The condensed milk takes longer but the lime flavor isn’t fighting anything.

Reply

Mia

The homemade sweetened condensed milk step looks intimidating but it’s what makes this SO different from every other keto key lime pie I’ve tried. Those cream cheese versions always have that dense cheesecake thing going on. This one actually sets like a real pie. One thing I figured out though: four hours minimum in the fridge, not two. I pulled mine at two and the middle was still a little wobbly. Four hours and it sliced perfectly clean.

Reply

Annie Lampella

Thanks for sharing what worked for you, Mia. The recipe card calls for 2-3 hours, or until set. Give it the full 3 hours if the center still feels soft, and overnight is fine too.

Reply

Riley

My husband has been dairy-free for about six months and has been missing out on every keto dessert I make. I’m determined to make this for him but I’m stuck on the filling because that homemade condensed milk is clearly the heart of it. Full-fat coconut cream is usually my go-to swap for heavy cream, but I’ve only ever used it in no-bake recipes, never in something where it’s actually being cooked down and reduced. Does coconut cream behave the same way when you simmer it with the butter and sweetener, or does it get grainy and separate? The crust swap (vegan butter for regular) seems more straightforward, so mostly just trying to figure out if the filling is salvageable before I commit to making it.

Reply

Annie Lampella

Coconut cream works but it’s more finicky. Keep the heat low and don’t rush it or it’ll separate. Reduces slower too, so add another 5-10 minutes. The coconut flavor that comes through is actually not bad with the lime.

Reply

Laniellle Baker

Can you make this with the one on one key lime flavor instead of real limes?

Reply

Annie Lampella Recipe author

I’m not sure how well that will work. It might work just fine, but the acid from the lime juice works with the egg yolks to solidify and thicken the pie when baked.

Reply

Jewelie Dee

578 calories a slice? Well, it better be good! (And I am sure it is.)

Reply

Annie Lampella

55 grams of fat in one slice. That’s real sweetened condensed milk, not a cream cheese shortcut. Worth it.

Reply

John

The prep output looked great . Then when I baked the pie crust it melted, and never cooked. I used oat flour instead of almond , And it went down hill from there :(.
I also couldn’t get the pie texture right , too liquidity.

Reply

Annie Lampella

Oat flour won’t work here. It doesn’t crisp up at all, so the crust just melts. For the filling, did the condensed milk reduce enough before you added the lime juice? If it’s still thin it won’t set.

Reply

Scot Aiena

I have learned so much from you Annie oh, you’ve made a big difference in my life. I follow you everyday and enjoy all your videos everybody in my family loves your recipes thank you my dear!

Reply

Annie Lampella

Love hearing that. Glad the whole family is along for the ride.

Reply

Keep going

More Dessert Recipes

2.8g NET CARBS
ice cream bars covered in chocolate stacked up with one covered in nuts
Dessert Keto Ice Cream Bars 185 min
1.3g NET CARBS
brownies stacked up with an avocado behind them
Dessert Keto Avocado Brownies – Flourless & Nut-Free 45 min
1.2g NET CARBS
A stacked pile of rich keto fudge squares with chopped walnuts visible inside each piece.
Dessert Keto Fudge 60 min
2.4g NET CARBS
whipped cream on top of warm gooey chocolate dump cake
Dessert Chocolate Hazelnut Keto Dump Cake 30 min
6.7g NET CARBS
Keto berry pie decorated like an American flag with blueberries, strawberries and raspberries.
Dessert Keto Berry Pie 80 min
2.7g NET CARBS
a sugar cookies decorated as a white bunny with pink ears and smile
Dessert Keto Sugar Cookies 33 min

See all 176 Dessert recipes

Get new recipes from Annie

One email a week. Unsubscribe whenever you like.