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.)
Print
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
CaitlinBrooks says
Hi there –
I’m new here and I love this site. I’ve made the snicker doodle crepes, cream cheese pancakes, pepperoni cauliflower pizza, and they turned out great. My grocery store didn’t have almond flour, so I used coconut flour for the lemon keto bars, and they didn’t turn out so well. I’ve never used almond or coconut flour before, but I’m thinking they’re not interchangeable. There are so many other recipes I can’t wait to try!
Mellissa Sevigny says
Hi Caitlin – for sure the almond and coconut flours are not interchangeable so I can see why you would have had trouble with the lemon bars recipe! I hope you’ll try it again with the almond flour because they are awesome! I get my almond flour online through Amazon because it’s so much cheaper than the stores! Also get a very fine almond flour like Wellbee or Honeyville for the best results in baked goods!
CaitlinBrooks says
Thanks Mellissa. I will order the almond flour. I appreciate the guidance, and I will try the keto bars again as the lemon part is awesome it was just the crust that was off. I’m using the left over egg whites to make the meringue cookies! I’ve done low carb off and on forever but all this creative baking is new to me! This site is beautiful!
vicky says
tried second time, split in the curd process..recipe has become too expensive..I’ll use crust for something else.. very sad as i love lemon.
Lara says
She said she used the green land o lakes gelatin which doesn’t gel. It’s just collagen. That’s probably why it split ☹️
vicky says
curd was lovely but when i added xanthan gum and gelatin it split. So sad.. Im going to try them without xanthan. reminded me of when cornstarch makes lumpy gravy
Dianna says
I don’t have any lemons, to make the zest, ….. can I use just lemon juice purchased in a bottle?
Mellissa Sevigny says
You can Dianna, but the flavor will be less intense and possibly too sharp without the zest to round it out. Not horrible, just not nearly as good as with the zest!
diana says
Well, I almost NEVER comment on a recipe that I haven’t made yet, but just gotta say, I am sure this is the one I’ve been looking for–lemon curd over an almond crust. Just have to get through the fabulous lemon pound cake with lemon glaze I made to go with the whipped cream and just-picked strawberries before I can get to this! Thanks–I’ll report back as soon as I make them!
Mellissa Sevigny says
The cake sounds amazing – hope you like the lemon bars just as much! :)
debbie says
Hi Mellissa! Planning to have this for my daughter. I wonder what can be a good substitute to almond flour? She’s allergic to gluten, nuts, soya. Thanks in advance!
Mellissa Sevigny says
Any cookie crust or sweet base layer will probably work so if you can find one that will work for her just top it with the filling and bake!
Michelle says
Is xanthan gum A necessity? I’m seeing more more of this with the recipes I guess I just got to go break down and buy some but I’m so new I have no idea what to get :-)
Leigh Ann says
I’m so glad I found this! I’ve been doing ultra low carb for 5 weeks now, and lemon bars are my absolute favorite dessert.
Mellissa Sevigny says
I’m glad you found it too Leigh Ann – hope you like them as much as we did!
Amanda says
What do you use to strain the filling? Would a metal mesh strainer work?
Mellissa Sevigny says
Yes Amanda, that would be perfect! It just needs to be fine enough to strain out any larger chunks of lemon zest or any lumps that might have formed while making the curd!
BarbaraLK says
Odd question … I have never figured out how to really zest a lemon. I have a fine grater/zester but it really doesn’t seem to work.
Tips? Suggestions? I am impaired in some things … :)
Mellissa Sevigny says
I find that my microplane grater works the best – some zesters are too small and they just grind it into mush making it hard to use. This is the one I have and it works great on lemon, parmesan, chocolate, etc. You can find all kinds of brands and price points in this basic style – even at your local department store probably!
barbara says
Thanks! I have one but I seem to get just goo. Maybe I am doing it wrong. I will try again. :)
Mellissa Sevigny says
There are different blade sizes that will give you a fine grate or a courser one – sounds like yours is too fine so go a size up and you should be good!
Kelsey says
Uh…are these still low carb if you ate a third of the pan in one sitting??? Holy Hannah Montana these are tastey.
Linda Buie says
I fear making them because I think I will eat all of them in one sitting. :)