These keto lemon bars strike that perfect balance of bright, tangy lemon flavor and a smooth, creamy filling on top of a buttery shortbread crust. If you’ve been missing a truly good low carb lemon bar, this one delivers.
They’re not quite a “dump and stir” recipe—but don’t let that scare you. The extra step is what gives these bars their rich, silky texture, and it’s absolutely doable (and worth it, I promise.)
If you don’t want to read the origin story of these keto lemon bars, please feel free to use the Jump to Recipe button on the top right of the page.
Lemon bars have always been one of my absolute favorite desserts. They are the thing I’m most likely to gaze longingly at through the glass at a bakery or coffee house – and sometimes I give in and have one.
I’m never really sorry until the next day when I wake up puffy and bloated from the gluten and sugar. Even then a perfect lemon bar is usually worth it if I’m being honest.
I finally decided though that it was high time I came up with a legit keto lemon bar recipe that would meet my low carb and gluten free criteria (and save me from the morning after bloating.)
As an added bonus these keto lemon bars are relatively simple to make, and just as good or better than the “real” thing. I’m not just saying that either, I tested these out on crowds of non low carbers at several parties – all with rave reviews and no leftovers.
This keto lemon bar recipe is basically the love child of my Lemon Almond Shortbread Cookies (crust), and my Sugar Free Lemon Curd (filling) recipes, with a few minor tweaks.
I like my keto lemon bars a little on the tart side, but you can increase the sugar free sweetener in the lemon curd if you prefer them sweeter – or you can add more powdered sugar free sweetener to the top of them after baking.
I’m confident that you guys are going to love these low carb lemon bars – they simply scream “IT’S SPRING BABY!” and they’ll make you believe it – no matter what time of year it is where you are.
These low carb lemon bars use a homemade lemon curd filling for a brighter, more authentic flavor than shortcut versions.
Recipe Notes:
- When zesting your lemons, make sure you don’t zest any of the white coating. That’s the pith and it’s super bitter – you just want the bright yellow rind, which is where the oils and therefore flavor are. The best tool for zesting a lemon is a microplane grater in my opinion, but a box grater on the side with the small holes in it can work too if that’s all you have.
- Use FRESH LEMON JUICE in these keto lemon bars. That bottled stuff just won’t taste the same. Since you need lemon zest anyway, you might as well take a few seconds to juice the lemons you’re zesting for a superior lemon flavor. A handheld lemon crushy thing like this one is what I use and it’s super easy.
- You will need 5 – 6 average sized lemons to make these keto lemon bars.
- When cooking the lemon curd for these keto lemon bars, DO NOT LEAVE THE POT UNATTENDED. Whisk gently but constantly until the mixture thickens enough to coat the back of a spoon, and it has lightened slightly in color. This may take 10 – 12 minutes, and it will feel like it’s never going to happen and then WHAM it’s there and it seems to be instantaneous. Be patient – I promise it’s worth it!
- Some people choose not to strain the curd after cooking, and leave the bits of grated lemon zest in the bars. It’s strictly a matter of personal preference and if you don’t mind the texture of the zest in there, it won’t hurt anything to skip that straining step.
As always I can’t wait to hear what you think! Make these keto lemon bars ASAP and report back STAT! Bonus points if you snap a pic and tag @ibreatheimhungry on IG!
(fyi said bonus points are completely useless, much like my passport in 2020.)
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Keto Lemon Bars
- Total Time: 40 minutes
- Yield: 16 bars 1x
- Diet: Diabetic
Description
An easy and tasty Keto lemon bar recipe that’s just as good or better than the classic – but low carb and gluten free!
Ingredients
For the Crust:
- 6 tablespoons butter
- 2 cups superfine blanched almond flour
- 1/3 cup granulated sugar substitute (I used Swerve)
- 1 tablespoon freshly grated lemon zest
For the Filling:
- 1/2 cup butter
- 1/2 cup granulated sugar substitute (I used Swerve)
- 1/2 cup fresh lemon juice (from 5 – 6 lemons)
- 1/4 cup grated lemon zest
- 6 egg yolks
- 1/2 teaspoon xanthan gum
- 2 tablespoons unflavored collagen powder (or 1 teaspoon unflavored gelatin)
Instructions
For the crust:
- Preheat the oven to 350 degrees.
- Melt the butter in the microwave or a small saucepan.
- Add the almond flour, sweetener, and lemon zest, stirring until fully combined.
- Press the dough evenly along the bottom and 1/2 inch up the sides of an 8 x 8 inch square pan. For best results line the pan with parchment paper or foil first, then you can simply lift out the completed lemon bars.
- Bake for 10 minutes.
- Remove and cool while you make the filling.
For the filling:
- Melt the butter in a small saucepan on low heat.
- Remove from heat and whisk in sweetener, lemon juice, and lemon zest until dissolved.
- Whisk in the egg yolks and return to the stove over low heat.
- Whisk continually until the curd starts to thicken.
- Remove from the heat and strain into a small bowl.
- Whisk in the the xanthan gum and collagen or gelatin until dissolved and smooth.
- Pour the filling over the pre-baked crust and spread out evenly to the edges of the pan.
- Bake the bars at 350 degrees (F) for 15 minutes.
- Remove and cool.
- Sprinkle with Powdered Swerve before serving if desired.
- Cut into sixteen 2 x 2 squares.
Notes
To see a list of my favorite low carb products and brands that I recommend for sweeteners, flours, etc. you can check out the IBIH Pantry Ingredients Page!
- Prep Time: 10 minutes
- Cook Time: 30
- Category: Keto desserts
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 2 x 2 square
- Calories: 193
- Fat: 19g
- Carbohydrates: 2g net
- Protein: 4g
More Keto Lemon Recipes You’ll Love
Keto Lemon Dressing aka. Vinaigrette
Keto Lemon Magic Custard Cake – Low Carb
Easy Keto Lemon Cheesecake – Low Carb
Keto Lemon Muffins – Low Carb and Gluten-free
58 best low carb lemon dessert recipes
Austin says
This recipe tastes wonderful! I have a tiny issue, the filling kind of grainy, I have that issue with sugar alcohol in chilled recipes, not just this one. I used powdered erythritol. I made a lemon curd from all day i dream about food site, she said all sugar alcohol re- crystalize when it is chilled. I wonder if you have any tricks. Thank you so much for sharing.
Mellissa Sevigny says
Mine never crystalizes and I use swerve typically. You could try a blend like lakanto which has monk fruit in it as well and might give you less of a grainy texture.
Austin says
i always use Swerve, i don’t know how you do it that never never crystallized, so lucky!! i have the same experiences with Carolyn at all day i dream about food website. here is what she said in many of her recipes ” If you use all erythritol based sweeteners, your sauce may re-crystallize somewhat as it cools.” all the recipes that need to be chilled turnout granny. I LOVE your chocolate peanut butter recipe but it re-crystllize some. just trying to figure out not to have that texture. thank you for your wonderful recipes on your website.
Tori says
All Day I Dream of Food creator Carolyn has a recipe for caramel sauce using Bocca Sweet that does not cool with grit. I feel like a scientist trying to use this technique in other recipes but it works. Love, love this recipe Melissa and all your recipes. Keto is much easier with these tasty little numbers!!
Jessica Barker says
Ummm…these are AMAZING!! I am a very skeptical keto dessert baker. I find that my cookies always crumble to bits and my breads tend to be either too soft or too crumbly or both. And while I realize that it is a skill to get something to be liquidy and crumbly at the same time, it is not in fact the texture I desire. These however, were perfection. So good, perfect texture and nobody believed they were keto. Thank you Mellissa!
Mellissa Sevigny says
So happy to hear it Jessica! Thanks for taking the time to leave a comment and review!
Rebecca Stephens says
Mine had great flavor but turned out very gritty. Is this the nature of baking with Swerve?
Mellissa Sevigny says
Not sure why yours were gritty? I have gotten a gritty texture with some things when using swerve but never these lemon bars. Wondering if some Swerve bags are off – so hard to tell. But no they shouldn’t be gritty, even when using swerve!
Yvonne says
Well, I read your comments leading up to this recipe and gave it a try. You didn’t disappoint! :)
My friend didn’t believe me when I made this recipe for her and told her it is keto. She has thrown out so many recipes that bombed when presented to hubby. These rock! Very strong lemon flavor and not too sweet. I halved the crust recipe, though. I like them much better without a thick crust. THANK YOU for giving us this recipe!
Mellissa Sevigny says
So happy it didn’t disappoint!
Gary says
Mellissa, it’s high time I commented on your wonderful recipes. I have followed your recipes for years (just last night I made your delish Keto cheddar leek cauliflower-mash!) Working from home, I have a few extra minutes so whipped up your Keto lemon bars. Not only was the crust amazing with a delicate crumb, but the lemon filling is out of this world!!! My husband loves all things lemon and this was a spectacular hit!! Reminds both of us of the Limoncello we always enjoy in Italy. I work for a large hospital system and every Christmas we have a cookie exchange. Old fashioned but fun. I’m bringing your lemon bars this year (if we’re allowed during this time). I’ll be proud to let my team know your lemon bars are sugar free and gluten free!! Thank you. -Gary
Mellissa Sevigny says
Thanks so much Gary – I appreciate you taking the time out to comment and let me know you guys enjoyed them – and I hope life will get back to normal enough for you to be able to share them this year!
V Lee says
Excited to make these today, what is a collagen powder substitute?? It’s the only ingredient that I don’t have.
jeff hashtag says
There is an alternative option in the recipe using unflavored gelatin.
Michael Lee says
I don’t know how you managed to devise a recipe nearly indistinguishable from the “real” thing, but you definitely did. My keto family is in awe about the flavor! (Definitely worth every minute.)
Mellissa Sevigny says
Thanks Micheal – I’m thrilled that it was a hit with everyone! I’m making a batch for us this week too and already can’t wait!
Susan says
I just want to say thankyou so much I won the contest so excited . Thank you so much again Melissa. By the way the recipe is great
Christina says
Hi there!! I am about to make these for the first time and was wondering if you have to use XANTHAN gum or if there is any substitute?? That is the only ingredient that I’m missing. Hope to hear back soon! Thanks in advance
Mellissa Sevigny says
You can omit it, they will just be a little looser!
Monica Nunez says
AMAZING! I made it with Limes because we leave in Florida, and lime is in our DNA :) Also, I was supposed to have Knox but last minute I realized we were out, so I added the same amount of orange Jello sugar free….. The result was incredible! We cut them in 32 pieces…. small but mighty! the perfect taste when you just want to satisfy the sweet tooth.