If you’re like me, you grew up on those powdered-sugar-dusted lemon bars at every potluck. They were perfect… until you saw the carb count. These are the low-carb redemption arc of that classic: all the lemon flavor, none of the sugar crash.
With a buttery almond flour shortbread base and a creamy lemon custard layer, these bars are equal parts refreshing and rich. Perfect straight from the fridge.
💡 What Solves the “Sad Keto Lemon Bar” Problem
Lemon bars can easily go wrong in keto form—either too eggy, too oily, or too bland. This one solves all of that by:
- Using real lemon juice for brightness
- A mix of powdered sweetener + stevia glycerite for balanced sweetness without cooling aftertaste
- Arrowroot or cornstarch (just 1 tbsp) to help the custard set like a dream
🧾 What I Used (And Why It Worked)
For the Crust:
- One batch of low-carb almond flour shortbread crust (buttery and dense, holds the filling well)
For the Filling:
- 1 cup freshly squeezed lemon juice – No bottled stuff. This brings the zing.
- ¾ cup low-carb powdered sweetener – Erythritol or allulose blend works best here.
- ½ tsp stevia glycerite – Boosts sweetness without needing more sweetener (optional).
- 1 tbsp arrowroot or cornstarch – Just enough to thicken the custard. Can be subbed with glucomannan.
- 5 large eggs + 2 yolks – Adds richness and helps the filling set perfectly.
- 1 pinch of salt – Balances the acidity and sweetness.
🔁 What You Can (and Can’t) Change
Swap | What It Does | My Take |
---|---|---|
Arrowroot → glucomannan | Zero-carb option, but more fragile | Use ½ tsp max |
Powdered sweetener → allulose | Smoother, slightly less sweet | Allulose gives a silkier custard |
Stevia glycerite → skip | Just add more powdered sweetener | Fine, but taste and adjust |
Add lemon zest | Boosts lemon flavor | Highly recommended |
⚠️ Keto Fails I Made First
What Went Wrong | Why It Happens | How to Fix It |
---|---|---|
Watery filling | Didn’t pre-bake crust | Bake crust 10 mins before adding custard |
Eggy texture | Overbaked the lemon layer | Bake just until set—watch closely |
Crumbly crust | Didn’t cool bars fully | Chill at least 3 hours before cutting |
Over-sweet | Too much stevia or sweetener | Always taste and adjust filling raw |
👩🍳 How to Make It (Step-by-Step)
- Preheat oven to 350°F (177°C). Prepare and pre-bake your shortbread crust for 10 minutes. Cool.
- In a mixing bowl, whisk together sweetener, arrowroot, and salt.
- Add eggs and yolks, whisk until smooth.
- Add lemon juice and mix until sweetener is dissolved.
- Pour filling over cooled crust.
- Bake 30 minutes, or until center is just barely set (don’t overbake).
- Cool completely, then chill for at least 3 hours before slicing.

🧠 Keto Cooking Tricks That Helped
- Use a metal 9×9 pan for even baking—glass can run hot.
- Add lemon zest to the filling for an extra flavor punch.
- Sift powdered sweetener to avoid clumps in the custard.
- For a pretty finish, dust with a little powdered monk fruit sweetener.
🧊 Storage + Reheating Without Ruining Texture
- Fridge: Store covered up to 5 days. Best served cold.
- Freezer: Freeze in layers between parchment. Thaw in fridge overnight.
- Do NOT microwave to reheat—custard will separate.
❓ Is This Really Sugar-Free?
✅ Yes!
It uses no sugar, only erythritol or allulose blends + stevia, and a small amount of arrowroot or cornstarch, which contributes <1g net carb per serving.
At 5g total carbs, 1g fiber, and 9g protein, these are 100% keto-friendly and diabetic-safe for most lifestyles.
📊 Full Nutrition Facts – Per 1 Bar (Out of 16)
Nutrient | Amount |
---|---|
Calories | 197 kcal |
Total Fat | 14 g |
– Saturated Fat | 5 g |
Cholesterol | 108 mg |
Sodium | 149 mg |
Potassium | 128 mg |
Total Carbs | 5 g |
– Fiber | 1 g |
– Net Carbs | 4 g |
Protein | 9 g |
Vitamin C | 9.9 mg |
Calcium | 40 mg |
Iron | 0.7 mg |
Check out More Recipes:
- Keto Lemon Cake – Sugar-Free, Fluffy, and Full of Zing
- Low Carb Keto Creamy Lemon Chicken
- Keto Pineapple Upside-Down Cake – Moist, Buttery, and Just 3.8g Net Carbs

Sugar-Free Lemon Bars – Low-Carb, Tart-Sweet, and Just 5g Total Carbs
Description
Buttery almond shortbread crust topped with creamy, tart-sweet lemon filling—these low-carb lemon bars taste indulgent without any sugar.
Ingredients
Instructions
- Preheat oven to 350°F. Pre-bake crust for 10 minutes, let cool.
- Whisk sweetener, salt, and arrowroot together. Add eggs + yolks, whisk smooth.
- Add lemon juice and whisk until combined.
- Pour over crust and bake 30 minutes or until just set.
- Cool fully, then chill 3 hours. Slice and serve cold.
Notes
- Crust must be cooled before adding filling.
- Add lemon zest for extra zing.
- Chill fully for clean slices.
- Best served cold, not warm.