Ingredients:

  • 4 large lemons (about 1 cup juice, reserve zest)
  • ½ cup (1 stick) unsalted butter, cut into cubes
  • 1 cup granulated sugar
  • 4 large egg yolks
  • 1 whole large egg
  • Pinch of sea salt

Instructions:

  1. Zest the lemons, being careful to avoid the white pith. Juice the lemons.
  2. In the saucepan (or heatproof bowl set over simmering water – double boiler method), combine lemon juice, lemon zest, sugar, and butter.
  3. Heat gently over low heat, stirring occasionally, until the butter is melted and the sugar is dissolved. (Don't let it boil!)
  4. In a separate bowl, whisk together the egg yolks and whole egg until lightly combined.
  5. Gradually whisk a small amount of the warm lemon mixture into the egg mixture to temper them (this prevents scrambling).
  6. Pour the tempered egg mixture into the saucepan with the remaining lemon mixture. Cook over low heat, stirring constantly with the whisk, until the curd thickens enough to coat the back of a spoon. This will take about 10-15 minutes. Aim for a consistency similar to thick custard or mayonnaise.
  7. Use a candy thermometer and make sure the curd reaches 170-175 F/77-79 C.
  8. For an extra smooth curd, pour it through a fine-mesh sieve into a clean bowl (optional).
  9. Transfer the lemon curd to sterilized jars. Let cool completely at room temperature, then seal and refrigerate. It will thicken further as it cools.