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
Shari Ann says
Hi Melissa, I absolutely love this recipe! I work for a huge Children’s Hospital with over a thousand employees and every so often our unit will have a bakesale to benefit the Children’s Miracle Network. So far these lemon bars have made us about $800 in the last year. I make a quadruple batch and sell them for $2 apiece. Well they sell out and about 10 minutes, so the last time I made them I sold them for $3 apiece and they were still gone in 10 minutes lol. I put label them with the nutritional info, and I also give people your website ( I hope that’s okay). Although hmmmm maybe I shouldn’t because then they can make their own! A LOT of people are doing keto apparently, and they all love your lemon bars.
Mellissa Sevigny says
This made my day Shari! How cool to know that my recipe is helping you guys earn money for charity! Thanks for letting me know it’s a hit and I hope they will keep performing for you at the bake sale! 😘
LadyJ1225 says
YUMMY!!!! I have always loved lemon bars and was so happy to discover this low-carb recipe. It is just the right amount of tartness for the lemon filling. And the crust is amazing! I could eat it by itself. Everyone who ate it raved about it. I had to grab a couple pieces quickly to save them for myself for later as they were going fast. Absolutely wonderful, whether you are following a low-carb diet or not.
Katie says
Awesome Recipe! By far my favorite low carb desert, you really cant tell its low carb.
Thank you for updating the gelatin/collagen ingredient quantity, that caught me the first time I made this and it came out extremely stiff and gummy like. It was perfect this second time with the 1 tsp of gelatin.
I also added one of the egg whites to the crust and it made it PERFECTLY stick together and had an even better texture.
Thanks for the recipe!
Susan says
I have a question. I wanted to make these this afternoon…I have all ingredients except the colagen/gelatin. Will it just be a gloppy mess if I leave that out?
Mina says
So many of your recipes are great, and this one is no exception. But, that one glaring error is still in the ingredients, and I, like many others over the years, followed the recipe as written without reading 10 minutes worth of comments, was blissfully unaware of the wording mistake in the recipe. Gelatin comes in powder and sheet form, Knox brand being the most available and well-known in Canada and the U.S. Apparently, what you are using in the recipe is not gelatin at all, but collagen powder, which also gels. Can you please change the ingredients to specify collagen, as opposed to true gelatin? I would hate to see any more people misled by this honest mistake and ending up with a yummy square of rubbery Jello.
Mellissa Sevigny says
Thanks for the reminder Mina, this recipe should have been updated years ago!
Sincity Lin says
Just made this recipe….currently in the oven. I put in Collagen peptides….is that the same thing as the collagen you all are talking about?
Will post finished product on instagram when completed!
Sammie says
Oh wow, these are phenomenal! They took forever to chill in the fridge so I could eat one, but worth the wait!!!! I used 2 lemons for the zest – was perfect, one in the crust and one for the filling. Next time I’ll probably bake the crust longer than 10 minutes, it didn’t brown at all, but man oh man, these taste like the non keto version, I’m in heaven!!! Thank you so much for such a fantastic recipe, I’ll probably be making this once a week!!
Inez says
I have never used 1/4 CUP of zest in anything. Is this correct? I only get a couple tsp from a large lemon.
Mellissa Sevigny says
It depends on how fine you’re grating it. If it’s really fine and packed down then 1 tablespoon will do it, but if you’re using larger shreds you’ll need the 1/4 cup. The more lemon zest, the more intense the lemon flavor.
Ellen says
Hi there, I made the recipe above, did it because everyone likes lemon. So it was my Easter dessert. The only comment people said they thought it was too much lemon. for both the crust and the insides, I feel it took about two large lemons. I will definitely make again, but just use less lemon. Just wondering though why do we drain the zest out, thought it might be nice to be in the filling? everyone loved the crust also by the way. It is 4 days after easter and crust is holding up great, it is in the fridg in tupperware. Just wanted to share it.
Laura says
My filling came out liquid-y…. ?. Failed on my part. Any suggestions? I noticed my filling wasn’t getting thick when I added the yolks..
Zandra says
I am new to keto and I have been struggling with the lack of sugar. Confession: I was eating way too much before I started. lol This recipe is everything I want and needed. I don’t normally comment on these things either, but I must so than anyone who loves lemon and wants a satisfying recipe, this is it. Hands down.
Dyana says
YUMMMM!!! Made these tonight & they are delicious!!! I used the boxed plain gelatin, and after reading a comment about them turning out rubbery, I used only 1 Tbsp instead of 2~turned out perfect!!!!