Sweet and tart, yet rich. Balanced and smooth. Lemon Curd is like dreamy sunshine in a bowl.
Take the top vessel off the pan of water and carefully dry the bottom before proceeding (you don't want water to drip into the curd). Pour the curd through a fine mesh strainer into a bowl set on a cooling rack. If using the lemon zest, stir it in now. Let cool for about 10 minutes, then cover with waxed paper or plastic wrap, pressing it onto the surface of the curd and up the sides of the bowl, so no air can get in. Chill.
Keep refrigerated in a lidded jar or other well-sealed container for up to two weeks (if it lasts that long).