Use a double boiler: Set a glass or ceramic bowl over a pan of barely simmering water.

Whisk and cook: Whisk together the eggs, sweeteners, lemon juice, and lemon zest. Whisk continuously until the mixture thickens, about 10 minutes. Watch carefully as it will thicken all of a sudden.

Add butter: Immediately remove from heat and add the butter. Let sit a few minutes to melt and then whisk until smooth and creamy.

Refrigerate: Chill in the refrigerator for 2 hours to set.

EXPERT TIPS

Always use a glass or ceramic bowl when making lemon curd. Lemon juice reacts with metal bowls and can give the curd a tinny or metallic taste.

The trick to perfect keto lemon curd is to take it off the heat at just the right moment. Keep a close eye on it at all times. The mixture will start to move more slowly and your whisk will begin to make tracks through it. The mixture will also become more opaque. Once it does, remove the bowl from over the pan to stop the cooking process.

Sweetener options: Curd relies on eggs to set properly so you can use your preferred sweetener. But do note that curd made with allulose alone takes a long time to thicken properly. It also stays a lot softer, even after refrigeration. Do not use liquid allulose, as it will introduce too much liquid into the mixture.

Dairy-free option: You can make dairy-free lemon curd by replacing the butter with coconut oil. Use only 3 tablespoons in place of the ¼ cup of butter.

Set a glass or ceramic bowl over a pan of barely simmering water.

Whisk together the eggs, sweeteners, lemon juice, and lemon zest. Whisk continuously until the mixture thickens, about 10 minutes. Watch carefully as it will thicken all of a sudden.

Immediately remove from heat and add the butter. Let sit a few minutes to melt and then whisk until smooth and creamy.

Refrigerate 2 to 3 hours to firm up.