- With the butter at room temperature, and cut into small pieces In a stainless steel bowl placed over a saucepan of simmering water, whisk together the eggs, sugar, and lemon juice until blended.
- Cook, stirring constantly (to prevent it from curdling), until the mixture becomes thick (like sour cream or a hollandaise sauce) (160 degrees F or 71 degrees C). This will take approximately 10 minutes.
- Remove from heat and immediately pour through a fine strainer to remove any lumps.
- Cut the butter into small pieces and whisk into the mixture until the butter has melted.
- Add the lemon zest and let cool.
- The lemon curd will continue to thicken as it cools. Cover immediately (so a skin doesn't form) and refrigerate for up to a week.
Makes 1 1/2 cups (360 ml).
If you want a lighter lemon curd whip 1/2 cup (120 ml) of heavy whipping cream and fold into the lemon curd