Why this recipe works:
Lemon curd is a custard-style sauce made from eggs, sugar, butter, and, of course, lemon juice. The most important step in this perfect lemon curd recipe is knowing when the curd is cooked. When the spatula leaves a clear trail (which quickly disappears) in the bottom of the saucepan, the curd is ready: it will be smooth and creamy. If you leave it on the heat any longer, the spatula will leave a wide, clear trail as the curd becomes thick and pasty.
- 1/3 cup lemon juice, from 2 lemons
- 2 large eggs
- 1 egg yolk
- 1/2 cup sugar (3 1/2 ounces)
- 2 tablespoons unsalted butter, cut into 1/2-inch cubes and chilled
- 1 tablespoon heavy cream
- 1/4 teaspoon vanilla extract
- Pinch table salt
- 1. Heat lemon juice in small nonreactive saucepan over medium heat until hot but not boiling. Whisk eggs and yolk in medium nonreactive bowl; gradually whisk in sugar. Whisking constantly, slowly pour hot lemon juice into eggs, then return mixture to saucepan and cook over medium heat, stirring constantly, until mixture registers 170 degrees on instant-read thermometer, about 3 minutes.
- 2. Immediately remove pan from heat and stir in cold butter until incorporated; stir in cream, vanilla, and salt, then pour curd through fine-mesh strainer into small nonreactive bowl. Cover surface of curd directly with plastic wrap; refrigerate until needed.