Keto Lemon Bars – Low Carb

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These keto lemon bars have long been an IBIH fan favorite, so I decided to freshen them up a bit with new photos and a few tips on helping them turn out perfect every time.

Keto Lemon Bars on a white plate

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 pretty easy 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.

3 Keto Lemon Bars on a rectangular white plate

I like my keto lemon bars a little on the tart side, but you can increase the sugar free sweetener in the 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. 

Top view of keto lemon bar on white plate


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. 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 lemon bars. 

blue porcelain bowl of lemons on a marble background

When cooking the lemon curd, 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.)


Keto Lemon Bars on a white plate

Keto Lemon Bar Recipe -Low Carb & Gluten Free

  • Author: Mellissa Sevigny
  • Prep Time: 10 minutes
  • Cook Time: 30
  • Total Time: 40 minutes
  • Yield: 16 bars 1x
  • Category: keto Desserts
  • Method: baking
  • Cuisine: American


An easy and tasty Keto lemon bar recipe that’s just as good or better than the classic – but low carb and gluten free!



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 56 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)


For the crust:

  1. Preheat the oven to 350 degrees.
  2. Melt the butter in the microwave or a small saucepan.
  3. Add the almond flour, sweetener, and lemon zest, stirring until fully combined.
  4. 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.
  5. Bake for 10 minutes.
  6. Remove and cool while you make the filling.

For the filling:

  1. Melt the butter in a small saucepan on low heat.
  2. Remove from heat and whisk in sweetener, lemon juice, and lemon zest until dissolved.
  3. Whisk in the egg yolks and return to the stove over low heat.
  4. Whisk continually until the curd starts to thicken.
  5. Remove from the heat and strain into a small bowl.
  6. Whisk in the the xanthan gum and collagen or gelatin until dissolved and smooth.
  7. Pour the filling over the pre-baked crust and spread out evenly to the edges of the pan.
  8. Bake the bars at 350 degrees (F) for 15 minutes.
  9. Remove and cool.
  10. Sprinkle with Powdered Swerve before serving if desired.
  11. Cut into sixteen 2 x 2 squares.


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!


  • Serving Size: 2 x 2 square
  • Calories: 193
  • Fat: 19g
  • Carbohydrates: 2g net
  • Protein: 4g

Keywords: Keto Lemon Bars, Low Carb Lemon Bars, Gluten Free Lemon Bars

A collection of the best keto lemon dessert recipes

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