Homemade Lemon Curd is a classic English custard, made with fruit juice, butter, eggs, sugar, and flavorings. After some gentle cooking, the result is a rich, smooth, creamy, melt-in-your-mouth spread that is at home in all kinds of different dessert treats.
Combine lemon juice, butter, and sugar in the top of a double boiler or in a glass heatproof bowl. Set the bowl with the butter mixture in it over a double boiler or a saucepan of simmering water, making sure the bottom of the bowl doesn't touch the boiling water; whisk until butter melts and sugar dissolves.
Gradually whisk 1/3 of hot butter mixture into the beaten eggs, whisk the mixture back into the bowl with remaining butter mixture, and set it over simmering water.
Whisk constantly until custard thickens and a thermometer inserted into mixture registers 160°F, about 5 minutes (do not boil). (If you don’t have a candy thermometer, wait until the mixture thickens and coats the back of a wooden spoon.)
Pour lemon curd through strainer set over clean medium bowl. Place plastic wrap directly on surface of lemon curd; chill overnight.
Notes
Curd can be kept refrigerated for up to 2 weeks in a jar with a tight-fitting lid.