Lemon curd makes a great filling for cakes or tarts. You can mix it with buttercream, drip cakes and more! Super easy to make and a great way to use those leftover egg yolks.
In a large glass bowl or non reactive metal bowl whisk together the egg yolks, lemon juice, zest, sugar, cornstarch, and salt.
Bring about a ½” to 1” of water to a boil in a medium saucepan, place the bowl with the mixture on top so that the steam from the water will cook the curd mixture.
Continuously whisk the mixture until the temperature reaches 170ºF-180ºF
Removing the curd at 170º will yield a thinner consistency while removing at 180º will be thicker.
Immediately add butter in small pieces. Whisk until smooth. Strain mixture to remove any large pieces of zest or seeds.
If using a metal bowl to cook the mixture, transfer to a glass bowl and cover the curd with plastic wrap so that it is touching the surface of the curd without any air bubbles in between, this will prevent a skin from forming on the top of the curd.
Refrigerate until cool before serving.
Store in the fridge for up to one week or freeze for up to a year