If you love the tangy-sweet flavor of classic lemon curd but want to keep things low-carb, this keto lemon curd is exactly what you need. It’s silky, bright, and spreads like a dream on almond flour biscuits, yogurt, or fresh berries. You’ll get all the zesty citrus punch without the sugar crash.
Best of all, it comes together quickly with simple ingredients you probably have on hand. Once you taste it, you’ll wonder why you ever bought the store-bought kind.
Ingredients
Method
- Zest and juice the lemons. Finely zest 1–2 tablespoons from clean, dry lemons, avoiding the bitter white pith. Juice enough lemons to get about 1/2 cup fresh lemon juice. Strain the juice to remove seeds and pulp.
- Whisk the base. In a medium, heavy-bottomed saucepan (off the heat), whisk together the eggs, powdered sweetener, lemon juice, lemon zest, and a pinch of salt until smooth. This helps prevent lumps later.
- Cook low and slow. Place the pan over low to medium-low heat. Cook, whisking constantly, until the mixture thickens enough to coat the back of a spoon, about 7–12 minutes. Do not let it boil. If you see steam or tiny bubbles, lower the heat.
- Add the butter. Remove from heat. Whisk in the butter, a few pieces at a time, until completely melted and silky. Add vanilla if using. The curd will look glossy and smooth.
- Strain for ultra-smooth texture. For a professional finish, pour the warm curd through a fine-mesh sieve into a clean bowl or jar. This catches any bits of cooked egg or zest.
- Cool and set. Press a piece of parchment or plastic wrap directly onto the surface to prevent a skin. Chill for at least 2 hours, or until thickened. It will continue to set as it cools.
What Makes This Special
This keto lemon curd uses a low-carb sweetener that mimics sugar without the aftertaste or crystallization. The texture is smooth and spoonable, just like the traditional version.
Real lemon juice and zest create bold flavor without needing extra thickeners. And because it’s gently cooked, it sets into a creamy, custardy spread that feels indulgent without the carbs.
It’s also versatile. You can use it as a topping, filling, or dip—and it’s easy to tweak the tartness and sweetness to match your taste. Think of it as your go-to citrus spread that happens to be keto-friendly.
Shopping List
- Fresh lemons (4–5 medium; you’ll need about 1/2 cup juice and 1–2 tablespoons zest)
- Eggs (4 large)
- Unsalted butter (6 tablespoons, cut into pieces)
- Powdered erythritol or powdered allulose (2/3 to 3/4 cup, to taste)
- Pinch of salt
- Vanilla extract (optional, 1/2 teaspoon)
Note: Powdered allulose gives the smoothest texture and won’t recrystallize in the fridge.
Powdered erythritol works well too, but keep it powdered to avoid graininess.
Instructions
- Zest and juice the lemons. Finely zest 1–2 tablespoons from clean, dry lemons, avoiding the bitter white pith. Juice enough lemons to get about 1/2 cup fresh lemon juice. Strain the juice to remove seeds and pulp.
- Whisk the base. In a medium, heavy-bottomed saucepan (off the heat), whisk together the eggs, powdered sweetener, lemon juice, lemon zest, and a pinch of salt until smooth.
This helps prevent lumps later.
- Cook low and slow. Place the pan over low to medium-low heat. Cook, whisking constantly, until the mixture thickens enough to coat the back of a spoon, about 7–12 minutes. Do not let it boil.
If you see steam or tiny bubbles, lower the heat.
- Add the butter. Remove from heat. Whisk in the butter, a few pieces at a time, until completely melted and silky. Add vanilla if using.
The curd will look glossy and smooth.
- Strain for ultra-smooth texture. For a professional finish, pour the warm curd through a fine-mesh sieve into a clean bowl or jar. This catches any bits of cooked egg or zest.
- Cool and set. Press a piece of parchment or plastic wrap directly onto the surface to prevent a skin. Chill for at least 2 hours, or until thickened.
It will continue to set as it cools.
Yield: About 1 1/2 cups, enough for spreading, layering, or filling small tarts.
Keeping It Fresh
Store your lemon curd in a sealed glass jar or container in the refrigerator for up to 1 week. For longer storage, freeze in small portions (silicone molds or freezer-safe jars work well) for up to 3 months. Thaw overnight in the fridge and whisk to restore smoothness if needed.
Tip: Allulose stays silky after chilling and freezing.
Erythritol can firm up slightly; a quick whisk or a few seconds over gentle heat brings it back.
Why This is Good for You
This curd packs bright citrus flavor with minimal net carbs, making it a smart treat for low-carb or keto lifestyles. Lemon provides vitamin C and a refreshing tang that makes small servings satisfying. The eggs add protein and nutrients, while butter contributes a creamy mouthfeel that helps with satiety.
By swapping sugar for a low-carb sweetener, you get the same dessert-like experience without spikes in blood sugar.
It’s a reminder that you can enjoy rich, classic flavors and still stay on track.
Common Mistakes to Avoid
- Too much heat: High heat can curdle the eggs. Keep it low and whisk constantly.
- Skipping the strainer: If you want smooth, bakery-style curd, straining is the quickest fix.
- Using granulated sweetener: Granules don’t dissolve as well and can leave a gritty texture. Use powdered sweetener.
- Not balancing sweetness: Lemons vary.
Taste the warm curd and adjust with a little more sweetener or juice before chilling.
- Letting it boil: Boiling makes the curd scramble and break. If it starts to bubble, lift it off the heat and whisk.
Variations You Can Try
- Meyer lemon curd: Use Meyer lemons for a sweeter, floral note. Reduce sweetener slightly.
- Extra rich: Whisk in 2 tablespoons heavy cream with the butter for a silkier finish.
- Lemon-lime twist: Swap 2–3 tablespoons of lemon juice for lime juice for a punchy blend.
- Lemon vanilla bean: Add seeds from 1/2 vanilla bean for a speckled, aromatic curd.
- Dairy-free: Use refined coconut oil or a dairy-free butter alternative.
Expect a slightly different set and flavor.
- Lavender lemon: Warm the lemon juice with a pinch of culinary lavender, then strain before mixing for a subtle floral note.
FAQ
Can I use monk fruit sweetener?
Yes. Most “monk fruit” sweeteners are blends with erythritol or allulose. Choose a powdered version.
If it’s an erythritol blend, you may need a bit more to match the sweetness of sugar; taste and adjust.
Why is my curd runny?
It likely needs more time over gentle heat. Keep whisking on low until it thickens enough to coat the back of a spoon. It will firm up more as it chills.
If you used a non-allulose sweetener, chilling can take a bit longer to set.
Why does it taste eggy?
Overheating can cause an eggy flavor. Cooking low and steady helps. A small splash of vanilla or extra lemon zest also balances any egg notes.
Can I make it without zest?
Yes, but zest adds a lot of lemon aroma.
If you skip it, consider using a touch more lemon juice or a drop or two of pure lemon extract to boost flavor.
How do I avoid lumps?
Whisk off-heat first, cook slowly, and strain at the end. A heavy-bottomed pan and constant whisking are your best friends.
Is it safe for kids?
Yes, it’s fully cooked. Just be sure to use a sweetener you’re comfortable with.
Some sugar alcohols may cause digestive upset if eaten in large amounts.
Can I use bottled lemon juice?
Fresh is best for bright flavor. Bottled juice can taste flat or bitter. If you must use bottled, add zest and a splash of vanilla to lift the flavor.
What can I serve it with?
Try it with almond flour scones, coconut yogurt, chia pudding, or layered into low-carb parfaits.
It also makes an excellent filling for keto tart shells or a topping for cheesecake.
Final Thoughts
Keto lemon curd brings a burst of sunshine to any low-carb kitchen. It’s simple, fast, and incredibly satisfying, with a texture that rivals the classic version. With a few smart ingredient swaps and gentle heat, you’ll have a jar of sweet-tart goodness ready for breakfasts, desserts, or a quick spoonful straight from the fridge. Make a batch this week and watch how many ways you find to use it.
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