Smooth, creamy, and packed with bright lemon flavor, this sugar-free lemon curd is a deliciously sweet treat—without the sugar! Naturally low-carb and a keto lemon curd, it’s perfect for spreading on toast, swirling into yogurt, or stirring into overnight oats for a refreshing citrus boost. Versatile and easy to make, it’s a must-try for lemon lovers. Check out the ‘How to Use Lemon Curd’ section for even more ways to enjoy it!
Winter is the best season to make this easy lemon curd when lemons are at their peak. Traditional lemon curd is made with eggs, lemon juice, sugar, butter, and zest. The only difference in this sugar-free version is swapping sugar for powdered allulose. It took extensive testing to get the recipe just right—but the results were worth it! The curd is just as smooth, creamy, and full of bright citrus flavor—without the added sugar.
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Why You'll Like This Recipe
- Bright lemon flavor.
- Sugar-free, low carb lemon curd, and keto diet friendly.
- Simple ingredients and simple to make.
- Won't spike your blood sugar with 1 net carb per serving.
- Make it thick, or make it pourable.
Love lemon? Try this tasty, high protein salad, lentil quinoa salad with a tangy lemon vinaigrette.
Recipe Ingredients
- Lemons: Fresh lemons for the juice and the zest. Both regular Eureka and Meyer lemons can work, but see the notes on lemon below.
- Sweetener: Use pure allulose powder, not an allulose blend. The powder dissolves beautifully and does not get grainy (crystalize).
- Butter: Use unsalted butter for lemon curd, no salt!
- Eggs: Large eggs, no cracks. I've skipped the whole egg and used just yolks for an extra rich lemon curd.
- Powdered citric acid: ONLY IF you are using Meyer lemons as the Ph of the juice is not high enough to set the lemon curd.
Please see the recipe card for measurements and full recipe.
What to do with those egg whites? Make a batch of these easy chocolate chip meringues.
Substitutions and Variations
- For using Meyer lemons, add a ¼ teaspoon citric acid.
- To substitute coconut oil for the butter, use either melted unrefined coconut oil (slightly alters the taste), or liquid/refined coconut oil (neutral flavored). The lemon curd may have a softer consistency but it will still be smooth and rich.
- For a dairy-free lemon curd, use unsalted plant-based butter (or coconut oil, above).
- For a totally smooth curd, omit the lemon zest.
Love lemon desserts? Try this lemon posset recipe or this fantastic lemon olive oil cake.
Chef's note on sweeteners: What is allulose? Allulose is a natural sugar substitute and naturally occurring sugar found at low levels in figs, raisins, wheat, maple syrup and molasses. It is not a sugar alcohol, like xylitol or erythritol (which I don't recommend). While the bag lists carbs in allulose, your body does not metabolize it. Adjusting for that fact, there is only 1 gram of carbs per serving. It's a terrific alternative sweetener of choice. Find more information on allulose here from Cleveland Clinic.
Does the Kind of Lemon Matter?
I tested this sugar-free lemon curd extensively—with both Eureka (standard grocery store variety) and Meyer lemons (I grow them), different ratios of yolks to whole eggs, and varying sweeteners—to find the best results. The type of lemons and sugar-free sweetener you use makes a big difference in how your lemon curd sets.
Standard Eureka or Lisbon lemons are ideal because their higher acidity helps the curd thicken properly.
Meyer lemons, on the other hand, have a lower acidity (higher pH), which means the curd won’t set as firmly. If using Meyer lemons, you’ll need to add powdered citric acid to compensate; otherwise, the curd will remain more of a pourable lemon sauce (which is delicious too!).
In terms of thickening and setting, it's best to let the lemon juice and heat do it's job. I tried adding xanthan gum to one batch that was thin, but it became gummy.
Recipe Instructions
Never made lemon curd? Here are step-by-step photos to show you how to make the best lemon curd, and all without sugar!
- Sift the powdered allulose to remove clumps or rocks.
- Zest and juice the lemons, separate the eggs, and cube the butter.
- Whisk egg yolks until smooth.
- Add lemon juice, allulose, and butter to a 3 quart medium saucepan, melt and whisk until smooth over medium heat.
- When butter-allulose-juice mixture is hot, slowly drizzle into the egg yolks whisking continually (tempering).
- Add the yolks mixture back into the pan, turn heat down, cook over medium-low heat whisking until thickened and reaches 180°F, 1-2 minutes.
Pour hot sugar-free lemon curd into a clean jar, cap, and refrigerate 4 hours to thicken or overnight. If the lemon curd thickens more than you want, stir in a little fresh lemon juice to thin to your preferred consistency.
Chef's tip: If you want to make a curd with other citrus fruits such as lime juice, it's as acidic as lemon juice so the curd should thicken properly. But it's sharper in flavor and you might need to adjust the allulose or add another sweetener to your taste. Consider combining lemon juice and lime juice for a lemon-lime curd!
How to Use Lemon Curd
If you need serving suggestions for sugar-free lemon curd, here are a dozen ways to use it:
- Spread between cake layers for a bright, citrusy filing.
- Swirl into muffin batter.
- Spread on toast, scones, or muffins.
- Fill crepes (gluten-free) for an elegant dessert.
- Top pancakes, like these Buckwheat pancakes for a terrific breakfast treat.
- Dollop on gluten-free waffles.
- Swirl into vanilla ice cream.
- Mix into oatmeal or high-protein overnight oats.
- Make a lemon curd blueberry yogurt parfait.
- Fill cream puffs.
- Pipe into vanilla cupcakes as lemon curd cupcakes.
- Thin the curd with a little lemon juice and pour it over fresh fruit or cheese cake.
Storage
According to the National Center for Home Food Preservation, if you store lemon curd in a well sealed airtight container in the refrigerator, it will last for up to a month (but it never lasts that long at my house).
Lemon curd can also be frozen for up to three months. Be sure to leave a half inch of air space in a well-sealed container. For thawing, place the container in the refrigerator for 24-48 hours.
One of my favorite summer grilling recipes for chicken breasts uses this terrific easy blender lemon marinade.
Recipe FAQs
Lemon curd thickens as it cools. If it's still too thin after chilling, it may not have been cooked long enough. Cook until it coats the back of a spoon and reaches 175°F-180°F (77-80°C).
It might also be the type of lemon you used. Regular grocery lemons such as Eureka and Lisbon lemons have higher acidity which helps thicken the curd. Meyer lemons have lower acidity and need additional citric acid to help set the lemon curd.
Yes! The butter adds richness and a silky texture, but you can omit it for a lighter, dairy-free version or use a non-dairy butter.
Simply put, no. Use fresh lemons. Bottled lemon juice usually contains preservatives and lacks the bright, fresh citrus taste needed for a good lemon curd. It also might vary in it's acidity levels and the acidity of fresh lemon juice is needed to thicken and set the lemon curd.
Strain lemon curd through a fine-mesh sieve after cooking to remove any bits of cooked egg. Straining ensures a silky, professional-quality curd. You can also skip the lemon zest.
More Lovely Lemon Recipes
If you love lemon, here are both sweet and savory lemon recipes to try.
Did You Make This Recipe?
If you make sugar-free lemon curd, please add your comment. I appreciate your feedback and enjoy hearing from you. If you loved it, please give it a 5-star rating! They really help other readers.
📖 Recipe
Sugar-free Lemon Curd
Equipment
- 3 quart pan I use a saucier, a great addition to your collection.
- Citrus juicer electric or hand juicer
Ingredients
- 4 tablespoons unsalted butter sub plant butter for no-dairy
- ¾ cup pure POWDERED allulose, sifted well not allulose with monk fruit
- 6 large egg yolks
- 2 large lemons, juiced and zested need ½ cup juice, optional zest
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Instructions
Prep work
- Separate the eggs for the yolks and save the whites for another use. Sift the allulose as it's often lumpy in the bag. Juice and zest the lemons. Strain the lemon juice. You need ½ a cup of lemon juice.
Cook the lemon curd
- Melt butter in the pan over medium low. Add the lemon juice and sifted allulose and whisk until smooth. Whisk the yolks until smooth in a medium bowl. When the butter lemon blend is hot, slowly drizzle it into the egg yolks whisking continually until totally incorporated. This is called tempering, so the eggs don't scramble.
- Pour the entire mix back into the pan and cook, whisking continually, until it thickens and reaches 175°F-180°F. Pour immediately through a sieve to catch any cooked egg bits. Stir in 1 tablespoon lemon zest if using.
- When it's finished, pour the liquid lemon curd into a clean jar, cap tightly and refrigerate 4 hours or overnight until set. If after refrigeration the lemon curd is thicker than you want, add a little fresh squeezed lemon juice and stir to reach the desired consistency.
- Lemon curd lasts in an airtight container for up to one month or frozen for up to 3 months. Thaw in the refrigerator for 24-48 hours and stir well.
Notes
Nutrition
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Porsche guy says
This is so tasty and so easy to make! My wife made it for me and I’m on a low-carb plan so this is perfect, no sugar and guilt free! I use it in oatmeal with blueberries. Thanks for the recipe.