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
Aimee says
Beautiful and delicious, but I get many more net carbs per bar. The almond flour alone came out to 64 net carbs. How were they calculated here?
Mellissa Sevigny says
Not sure what you’re using to calculate but your net carbs on the almond flour are way off, so I’m guessing the rest of the numbers are as well.
Antonia K Barry says
These looked great, were not too hard to make. I made the crust thinner and doubled the curd. My lemons must have been very strong, because, goodness! -these were tart! Next time I’ll back off on the zest, and increase the sweetener, but they were amazingly good.
Linda says
A 5 star. Easy and turns out beautiful! What a great treat when low carbing can be tedious. I only added a touch of vanilla. Served with homemade whip cream! Thank you!
Mellissa Sevigny says
Thanks Linda, I’ve never tried these with vanilla but I’m intrigued! Will add a bit to my next batch, thanks for the idea!
Tessa says
I’d like to know this as well pls
Kylie Jones says
I am about to try this tomorrow – have lots of lemons so can it be frozen?
Mary Alice says
I have the same question. I’ve made this before and it is outstanding, but I’d like to eat it just occasionally over the next few weeks as I continue to work on weight loss. Has anyone tried to freeze it? If no one knows, I guess I’ll try to freeze just one piece and see what happens. :)
Mellissa Sevigny says
I’ve never tried freezing them – let us know how it goes if you try it!
Eve says
Yes I’ve had success freezing these
Eve says
Yes I’ve had success freezing these
Constantin Trudel says
BEST LEMON BAR RECEPIE PERIODE!!! They are so good and Keto?!?!? WOW!!!! Anyone hesitating should try this recepie!
Mellissa Sevigny says
Thanks so much! These are still one of our favorites! 😘
Teresa says
Can I use any substitute for the xanthan gum?
Lisa McGill says
unflavored gelatin not sure of how much though sorry
Lauren Lee says
I am looking forward to making this recipe as a keto friendly dessert for mother’s day. I wanted to know am I using unsalted butter or salted? Thank you!
Mellissa Sevigny says
Salted is what I always use Lauren!
Janice Winch says
Okay…I’m not sure what happened but when I printed this recipe, a while back…it called for 4 cups of the flour and comparing to recipe above, looks like it doubled all the rest of the ingredients but still called for 8 x 8 square pan…and to bake for 15 minutes!! I just pulled it out of the oven, after 45 minutes. Here’s hoping.
Mellissa Sevigny says
You may have hit the 2x at the top of the recipe which will double all of the ingredients?
S says
Whoa. I think this might be the best keto dessert I’ve ever made. Absolutely delicious! The only thing I might try differently next time is using powdered sweetener in the filling; I used granulated Lakanto and it didn’t end up dissolving completely. Thank you so much for this recipe.
Anniebananie says
These were fab! Any ideas for a butter substitution? I want to make for a friend who can’t have any dairy. Thanks!
Mellissa Sevigny says
So happy you enjoyed them! I suppose a dairy free margarine (while not healthy) would be a good sub for someone who can’t have the dairy.
Jo says
I used ghee instead of butter. I’m also lactose intolerant, so there’s no lactose in ghee. As long as your friend isn’t vegan, this will work for them too.