Keto Lemon Curd (Silky, Never Gritty, 1g Net Carbs)
- Total time
- 3 hours 20 minutes
- Makes
- 12 servings (2 tbsp)
- Net carbs
- 1g
- Calories
- 98
The first sugar-free curd I made was beautiful in the pan. Bright yellow, glossy, thick. I put it in the fridge feeling very pleased with myself, and the next morning it crunched. Tiny crystals all the way through, like someone had stirred in sand.
The second batch I rushed over too much heat. It thickened in seconds, then split into little flecks of scrambled yolk.
This keto lemon curd fixes both. It is sharp and sweet at once, thick enough to hold a spoon upright once it has chilled, and it stays perfectly smooth in the fridge for a week. Six ingredients, ten minutes at the stove, and 1g net carbs for two generous tablespoons.
Why This Keto Lemon Curd Stays Silky
Allulose instead of erythritol. This is the whole story of the crunchy jar. Erythritol dissolves in warm curd and then crystallizes again as it chills. Allulose stays dissolved, so the curd is as smooth on day five as it was on day one.
Yolks only. Six yolks give a rich, deep yellow curd that sets soft and spoonable. Whole eggs set firmer and taste more eggy.
Low heat and a whisk that never stops. Egg yolks thicken somewhere around 170°F and scramble not far above it. On low heat, with constant whisking, you have a wide window to catch it.
Strain it, then add the zest. Pressing the hot curd through a sieve catches any bits of cooked egg. The zest goes in afterward, so the little yellow flecks and all that lemon oil stay in the jar instead of the strainer.
Recipe Overview
- Prep Time: 10 minutes
- Cook Time: 10 minutes
- Chilling: 3 hours
- Total Time: 3 hours 20 minutes
- Makes: about 1½ cups, 12 servings of 2 tablespoons
- Net Carbs: 1g per serving
Ingredients
| Ingredient | Quantity | Notes |
| Unsalted butter | ½ cup (113 g) | Cubed |
| Fresh lemon juice | ½ cup (120 ml) | About 3 to 4 lemons |
| Powdered allulose | 1 cup (160 g) | Not erythritol |
| Large egg yolks | 6 | |
| Fine salt | Pinch | |
| Finely grated lemon zest | 1 tbsp | Zest the lemons before you juice them |
Use fresh lemons. Bottled juice tastes flat and slightly bitter once it is cooked, and in a curd there is nowhere for that to hide. Zest the lemons first, while they are whole and firm, then juice them.
Powdered allulose dissolves fastest. Granulated works too, but whisk it with the juice for an extra minute before the yolks go in. Allulose is a little less sweet than sugar, which is why the amount looks generous.
Cook it in a stainless steel or enameled pan. Lemon juice reacts with aluminum and can give the curd a gray tinge and a metallic taste.
Recipe Timing
| Order | Step | Time |
| 1 | Melt the butter, whisk everything in | 3 minutes |
| 2 | Cook on low, whisking, until thick | 8–10 minutes |
| 3 | Strain and stir in the zest | 2 minutes |
| 4 | Cool, then chill to set | 3 hours |
How to Make Keto Lemon Curd
1. Melt the butter
Put the butter in a heavy stainless saucepan over low heat and let it melt slowly. Do not let it bubble or brown; browned butter turns the curd beige.
2. Whisk in the rest
Take the pan off the heat. Whisk in the lemon juice, the allulose, the egg yolks and the salt until the mixture is smooth and evenly yellow. Taking it off the heat first means the yolks hit warm butter, not a hot pan.
3. Cook it low and slow
Put the pan back on low heat and whisk constantly, getting into the corners, for 8 to 10 minutes. It goes from thin and frothy to pale, then suddenly thickens. It is ready when it coats the back of a spoon and a line drawn through it with your finger holds clean, or reads 170°F on a thermometer. Never let it boil. If you see a bubble, pull the pan off the heat and keep whisking.
4. Strain, then zest
Set a fine-mesh sieve over a bowl or a clean jar and pour the hot curd through, pressing it with a spatula. Scrape the underside of the sieve too; a lot of curd clings there. Stir the lemon zest into the strained curd.
Now taste it. Lemons vary a lot, and some batches come out sharper than others. If it makes you wince, whisk in another tablespoon of powdered allulose while the curd is still warm enough to dissolve it.
5. Chill it
Press a piece of plastic wrap right onto the surface so no skin forms, let it cool for about 30 minutes, then refrigerate for at least 3 hours. It will look thin when hot. It sets as it chills, into a thick, spoonable curd.
Recipe Tips and Variations
Runny after chilling? It came off the heat a little early. Pour it back into the pan and whisk on low for a few more minutes until it coats the spoon properly, then strain and chill again.
Lime, orange or grapefruit curd. Swap the lemon juice and zest for the same amount of another citrus. Lime is wonderful. Orange is much sweeter, so use a little less allulose.
Lemon cream. Whip 1 cup of heavy cream to soft peaks and fold in half a cup of chilled curd. It is the easiest filling there is for a layer cake or a bowl of berries.
Dairy-free. Swap the butter for 4 tablespoons of mild extra virgin olive oil, whisked in slowly after the curd comes off the heat.
Serving Suggestions
Spread it thickly on a toasted keto english muffin, where it pools in all the nooks. Roll it inside keto crepes with a few raspberries, swirl it through plain yogurt, or spoon it over pancakes with whipped cream.
The best use of all: this recipe leaves you with six egg whites, which happens to be exactly what my keto pavlova needs. Crisp meringue shell, soft middle, cold lemon curd and berries on top.
Storage
Refrigerator: up to 1 week in a clean, airtight glass jar. Keep it cold; it is an egg custard.
Freezer: up to 3 months in a freezer-safe container. Thaw it overnight in the fridge and give it a stir before using.
Frequently Asked Questions
Why did my keto lemon curd turn gritty?
It was almost certainly sweetened with erythritol, which recrystallizes as the curd chills. Make it with allulose and it stays smooth. If you only have erythritol, use the powdered kind and expect a little texture after a day.
Why is there scrambled egg in my curd?
The heat was too high, or the whisking stopped. Keep the burner on low, whisk the whole time, and pull the pan off at the first bubble. Straining catches any small bits that do form.
Can I use bottled lemon juice?
It will set, but it tastes noticeably flatter and a little bitter. Fresh juice is worth the few minutes of squeezing, and you need the zest from fresh lemons anyway.
What can I do with the leftover egg whites?
Six whites make one keto pavlova, which is the obvious partner for this curd. Two of them make a tray of my keto brownie bark. They also keep in a covered jar in the fridge for a few days, or frozen for months, until you need them.
How many carbs are in keto lemon curd?
Two tablespoons come to 1g net carbs and 98 calories. The allulose is not counted, in line with how it is treated across this site.
More Keto Lemon Desserts
- No-Bake Keto Lemon Cheesecake — a lemon filling that actually sets firm, on an almond flour crust.
- Keto Lemon Loaf — superfine almond flour, real lemon zest and a sweet lemon glaze.
- Keto Cloud Cake — a soufflé-light cake of eggs and cream cheese, lovely with a spoonful of curd on top.
- 4-Ingredient Keto Ice Cream — a creamy coconut milk ice cream that takes a ripple of lemon curd beautifully.
Recipe Card
The full ingredient list and the short method are in the card below.
Keto Lemon Curd
Equipment
- Heavy stainless steel saucepan not aluminum
- Whisk
- Fine-mesh sieve
- Glass jar with a lid
Ingredients
- 1/2 cup unsalted butter 113 g, cubed
- 1/2 cup fresh lemon juice about 3-4 lemons
- 1 cup powdered allulose 160 g
- 6 large egg yolks
- 1 pinch fine salt
- 1 tbsp finely grated lemon zest
Instructions
- Melt: Melt the unsalted butter in a heavy stainless saucepan over low heat without letting it bubble.
- Combine: Off the heat, whisk in the fresh lemon juice, powdered allulose, large egg yolks and fine salt until smooth.
- Cook: Return to low heat and whisk constantly 8-10 minutes, until it coats the back of a spoon and a finger line holds, or reads 170°F. Do not let it boil.
- Strain: Press the hot curd through a fine-mesh sieve into a bowl or jar, then stir in the finely grated lemon zest.
- Chill: Press plastic wrap onto the surface, cool 30 minutes, then refrigerate at least 3 hours to set.
Notes
Keep cooking
