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
Alfie says
Great recipe! Everything went as it should
during, yet my crust is SUPER soft. They’re not cool yet and I put them in the fridge before cutting any further. Any idea why my crust didn’t stay firm? Taste is on point though!
Mellissa Sevigny says
The crust will firm up when cooled for sure. As long as you pressed it into the pan and didn’t just spread it loosely before baking, then it should be firm enough to hold in your hand without crumbling.
Dottie Cassidy says
Help! I’m not an inexperienced baker, but the filling turned out so rubbery! I used fresh squeezed lemon juice, and based on comments, used 1 packet (a little less than 1 tablespoon) of Knox gelatin and used no xantham gum. I did use granulated pure Allulose instead of Swerve. I know it’s a great recipe because so many others love it, but my filling was inedible – so sad.
Mellissa Sevigny says
The recipe clearly calls for 1 TEASPOON of unflavored gelatin (I also use the Knox brand) and not “a little less than 1 Tablespoon” which is almost 3 times the required amount. That is why they turned out rubbery and inedible.
Austin says
I have *quite literally* zero baking experience, but I’ve been craving a sweet treat ever since starting keto a month ago.
Oh. my. god.
I would pay a fortune to buy one of these bars at the bakery. To think I just made a whole batch myself!
You’ve earned yourself a new follower, Miss Mellissa. Thank you so much for this delicious recipe.
Mellissa Sevigny says
That’s so awesome to hear Austin, thank you! Maybe YOU should start charging a fortune for them to your other keto friends now that you’re a pro baker! 🙌🏻😂
Melissa says
I’ve made these before and they’re fantastic.
Lori Mc says
This is absolutely wonderful. This is the second time I’ve made the lemon squares. My favorite part is that it is so hard to get all the filling out of the pot through the strainer. So I am forced to lick the spatula. I don’t know how I survive. Thank you so much.
Mellissa Sevigny says
If these didn’t taste good then it’s likely you used store-bought lemon juice instead of fresh, and probably an off brand at that. This is one of my most popular keto dessert recipes with many positive comments, so that’s the only explanation I can think of for why yours didn’t also taste delicious.
My Keto Snack Box says
Love the recipe for the Lemon bars! This is a perfect snack to eat for breakfast or as dessert. Hoping to make this for our teams holiday event! Thank you :)
Cecile Ullrich says
Hi Mellissa, quick question, do I dissolve the gelatin – like you would normally or do I just add the granules?
Mellissa Sevigny says
Yes, just sprinkle and stir.
Cara says
Wow! I FINALLY made a low carb dessert that turned out amazing! I never write reviews because if I do not like something, it’s probably because of me and not the recipe but these lemon bars are out of this world! I took a bite and actually said “wow!” out loud! This is one recipe I’ll be making way too often!
And yes, I had to make a change. 🤦♀️. I didn’t have unflavored collagen ( only had chocolate) and didn’t have gelatin so I substituted more xanthan gum and it worked! I already made sure this recipe is printed and in my suitcase for our vacation to the cabin in the woods in a couple of months! Definitely not leaving home without it!
Mellissa Sevigny says
So happy that you finally found a Keto dessert that you actually like! 🙌🏻
Gigi says
How much extra xanthan gum did you use?? I don’t have gelatin or collagen either!!
Kate says
How much additional xanthan gum did you add instead of collagen? Thank you in advance!
Deana Chadwick says
Fantastic tart Lemon squares! I could eat the curd on its own by the bowl full. I started preparing before I gathered all if my ingredients, big mistake. I know I have gelatin somewhere, but couldn’t find it and this was after my custard was finished. I spent 10 panicked minutes online looking for a sub… I almost used Konjac, but ended up going with chia seeds (figured that I could always use more omega 3’s). It came out amazing! My skinny, sugar loving, boyfriend couldn’t stop eating it; I had to direct him to t h e chip ahoy’s so he didn’t eat all if the squares. Thank you Mellissa for another great recipe!
Joy says
I LOVE this recipe yet would add a disclaimer- Collagen gives off a very unsavory aroma while baking, which lingered after bars were out of the oven. I could also taste it after they came out of the oven- BUT- after refrigerating overnight I am no longer noticing it.
I also experimented using 1/2 almond flour, 1/2 pecan flour, and I reeeaaallly like it. :p
BTW- konjac powder in place of xanthan worked fine- just be sure to get any lumps out and stir in quickly to prevent new lumps from forming.
Joy says
(My comment above should have been in the main comments, not just as a reply).
Mellissa Sevigny says
Maybe it’s the brand of collagen you are using – I never have any odor or flavor in mine warm or cold?