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
Rhonda says
Not sure what I did wrong. I subbed coconut flour because of alergies but that is the only change I made. My crust ended up about 2 inches thick and didn’t hold together at all. I mixed it, it seemed really dry but I used the right quantities so I went with it. Baked it 10 min and it still seemed wrong but I just kept going. In the end I ended up with 2 inches of what was basically flour under my custard. Well the flour is expensive so to salvage it, I mixed the whole mess together, added a ton of oil and some egg whites, and put them in my brownie pan, now they’re more like lemon blondies. Any ideas on what the problem might be? 2 cups of flour seemed to be way too much. I’ve checked the recipe about 5 times to make sure I didn’t miss something. I am going to try again but I may cut the flour in the crust in half, or even less
Mellissa Sevigny says
Coconut flour and almond flour are not equally interchangeable. 2 cups of almond flour – or find another coconut flour crust to use as a base and just make the filling to put on top.
Lara says
There a plethora of coconut flour crust recipes, found this on my first search.
http://www.sugarfreemom.com/recipes/low-carb-coconut-flour-pie-crust/
Also found this on substituting:
1.Coconut flour absorbs a lot of liquid. For every 1 cup of coconut flour, use 6 eggs and 1 cup of liquid.
2.1 cup all-purpose flour = ¼-1/3 cup coconut flour.
3.Coconut flour can be baked at the same temperature as other recipes, no need for adjustment.
susie says
I never ever comment on recipes but I just had to for this one. It is AMAZING and so worth the time. I need to now give some away otherwise I will eat it all by myself.
Mellissa Sevigny says
Welcome to my world Susie ha ha!
Roxanne says
I have all these ingredients on hand except for the xanthan gum. Is it possible to omit or substitute?
Janet Voris says
Just wonderig how important is the xanthan gum? I don’t have any, but could get some.
Mellissa Sevigny says
You can get away without it they won’t be quite as firm tho!
Eric says
Just made these with farm fresh egg yolks and fresh lemon juice. The deep orange color is Amazing! Wish I could send you a picture. Can’t wait for them to cool!
Sara says
This recipe is perfection! I used stevia glycerite instead of the swerve. I put in 1 tsp for the crust and 2 tsp in the filling. Sooo yum!! Thank you for this!
Lorna Hodkinson says
HI, just wanted to ask if these freeze? if not, how long do they keep for in the fridge? I have visions of myself eating the whole batch to “avoid waste” lol.
Mellissa Sevigny says
I haven’t frozen them but they’ll keep in the fridge for 4 or 5 days easily! And yes, not eating the whole batch is a legit concern! ;)
Eric says
We froze them with excellent results. Actually quite good when eaten half thawed
Amanda says
Yum! I’m not sure if I didn’t bake them long enough, as the lemon curd part stayed somewhat soupy, but…no matter! I ate them with a spoon, and they were still delicious! Thanks for the recipe!
Amanda says
Update: They firmed up in the refrigerator…and remained delicious! I can’t wait to make these at Christmastime!
Nicola says
Sounds delish!! I only have gelatin packets. Would I need 2 whole Tbsps of the packet stuff? I want to make these NOW!!!! LOL
Mellissa Sevigny says
You could probably reduce it to 1 Tbsp if you’re using regular gelatin!
Amanda says
These are delicious and it’s a great recipe. Unfortunately there is one very important huge problem: they aren’t really keto friendly. I’m wondering how u got 2net carbs each. My mom made these & i binged on them without doing my own calculations and got really really sick (out of ketosis & sugar alcohol overload). Doing the calculations for the crust ALONE with 1/3 cup swerve and 16 servings, it is WAY over 2g carbs.
According to my math for the whole recipe, calculating NET CARBS even for the almond flour, there are AT LEAST (being minimally liberal) 15 GRAMS OF NET CARBS PER SERVING. That’s more than I usually eat a DAY. (Oh my god no wonder I was sick for 2 days. I’ve been working at keto adaptation for a month and a half & want to cry).
***PLEASE PLEASE PLEASE DO NOT EAT THESE IF YOU ARE ON KETO!!!!*** at least 15 carbs a serving!
Mellissa Sevigny says
YOU ARE INCORRECT. CALM YOURSELF. The sky is not falling and these lemon bars are PERFECTLY KETO FRIENDLY when the nutrition information is calculated correctly and you don’t “binge” and eat the entire pan. One batch of crust and filling has a total of 36 grams of net carbs – when you divide that by the 16 two by two squares that constitute one serving, you get 2.25g net carbs per square. You got sick and kicked out of ketosis because you ate too many – my recipe is not to blame, your lack of moderation is.
Amanda says
SORRY! I was freaking out. I’m brand new to Erythritol and did not understand that the listed sugar carbs in that sweetener are completely indigestible and apparently don’t count at all. Your recipe is superb.
Susan Huth says
Love your reply! :D
I have a question about lemon juice. Approx how many lemons in the recipe? Also, what do you think about using bottled “real” lemon? But then there is the zest… hmmm.