I make my lemon curd without butter because I like its intense lemony flavor. I even enhance it with a few tablespoons of my bitter-sweet lemon marmalade. Butter makes a smoother and creamier lemon curd, so it is up to your personal taste.
Also, I don’t pass the cream through a fine sieve as the classic French and old English tradition dictates. The occasional tiny lumps don’t bother me.
If you want to make more lemon curd, repeat the process, which only takes about 10-12 minutes. I have found that it is difficult to whisk and cook properly more than four eggs at a time.
For about 1 2/3 cups
Zest of 1 1/2 – 2 organic very fresh lemons (depending on the size of the lemons and on how lemony/bitter you like the curd)
1/3 cup sugar
2-3 tablespoons lemon marmalade
1/2 cup fresh lemon juice
4-6 tablespoons unsalted butter (optional)
4 eggs (medium or large)
In a small bowl toss the zest with the sugar, stirring to mix, and set aside.
In the blender pulse the marmalade with the lemon juice, add the sugar and zest and pulse once more. With a rubber spatula transfer to a stainless steel or flameproof glass bowl, stir in the butter, if you use it, and place the bowl on top of a saucepan with simmering water. The water should not touch the bottom of the bowl.
In a clean bowl break the eggs and whisk them with a hand-held mixer until very frothy. Whisk the sugar-lemon mixture on top of the boiling water –I use the hand-held mixer— and add the eggs, whisking constantly, until the mixture thickens to the consistency of cream. Remove the pan from the heat but continue to whisk the lemon curd for another minute.
Transfer to one or two small jars, cover the surface with a piece of parchment paper and let cool. Close the jars and refrigerate.
It keeps for 5 weeks, or longer.