You can use a double boiler for this recipe, but it is actually easier to whisk the lemon curd as it cooks if you make a double boiler setup from a stainless- steel bowl set into a saucepan with an inch or two of simmering water. The bottom of the bowl should not sit directly in the water and the water should be kept below a rolling boil for the best results. You can strain the curd to remove the zest for a silky smooth texture, or leave it unstrained for a more textured curd.
- 9 large egg yolks
- 2/3 cup lemon juice
- 3/4 cups sugar
- 4 teaspoons lemon zest
- 14 tablespoons butter, cubed, room temperature
Bring an inch or two of water to a simmer in a saucepan or the bottom of a double boiler.
Combine the egg yolks, lemon juice, sugar, and zest in a stainless mixing bowl or the top of a double boiler and whisk until the sugar is completely dissolved. Set the mixture over the simmering water and continue to whisk until the eggs are thickened and warm, about 12 minutes.
Add the butter a few pieces at a time, stirring until each addition is blended into the eggs before adding more. Continue stirring until all of the butter is blended into the curd.
Transfer the curd (straining if desired) to a bowl set in an ice bath and cool, stirring from time to time. Once the curd has reached room temperature it is ready to serve or store in a covered container in the refrigerator for up to 3 days.