Step 1

Note: Before you start, you may want to refer to the above post which contains useful information.

Step 2

In a medium heatproof bowl, place eggs, sugar, lemon zest, and juice and whisk to combine. Place the bowl over a saucepan of simmering water (bain-marie). Cook on moderate heat, whisking constantly, until mixture becomes thick (mine was ready in 10 minutes). If you have a thermometer, it should register 170F/75C; otherwise, it should coat the back of a wooden spoon and leave a clear pass if you run your finger through it. The curd will thicken more once cooled.

Step 3

Remove from heat and immediately strain mixture through a sieve. Add butter and whisk until completely melted and incorporated, and mixture is smooth.

Step 4

Cover and refrigerate for at least 4 hours. Sometimes a “skin” can form on the surface of the curd. To prevent it, press a piece of plastic wrap directly onto the surface.

Step 5

Lemon curd can be kept in an airtight container in the fridge for up to a week, or can be frozen for up to 2 months. To thaw, place overnight in the fridge.