Lemon curd, a thick tangy custard, is cloyingly decadent but delivers an aromatic sharpness that screams summer. It is the perfect dessert to encourage winter to get a move on and let spring have some room, without resorting to eating salads. Use this curd to fill cakes, pies, and tarts (store bought crusts work well), to top muffins, cupcakes, cookies and crepes or to serve with fruit, crusty bread or in trifles and parfaits.
Zest of three lemons: the zest is the yellow outer skin of the lemon – not the intensely bitter white layer right underneath – and it’ll give the lemon curd its intense lemon flavour. Use a fine grater to remove it.
¼ pound of butter (1 stick), soft
1 cup of sugar
¼ teaspoon salt
Juice of two lemons, three if you like it tangy
Begin by setting up a double boiler. For this, boil a large pot half full with water. Next, you will need a heat-proof mixing bowl that can rest on top of this pot without the bottom touching the surface of the water. You will only need to put the mixing bowl on top of the boiling pot of water when directed to below.
With a whisk, mix the lemon zest, butter, sugar, and salt together in the mixing bowl until creamy for just a couple of minutes.
Add the eggs and lemon juice and continue to whisk until incorporated.
Turn the heat down on the boiling water to a bare simmer. You want the steam to rise and heat the mixing bowl when you place it on top, but do not want the water to boil vigorously. Ensure there is always some water in the pot so that it doesn’t boil dry.
Place the bowl on top of the pot, and switching to a wooden spoon or heat-proof spatula, stir every twenty seconds or so for ten minutes. After this, stir constantly for another five to ten minutes to prevent curdling until the curd is the consistency of thin pudding. The curd should never boil (partly why we are using a double boiler) and will thicken below boiling point.
If curdled at all, or if you don’t like small bits of lemon zest, strain before cooling.
Cool, cover with plastic wrap (make sure it touches the surface of the lemon curd to prevent a skin forming) and refrigerate for at least two hours before serving. It will thicken even more as it cools.
Curds can be made with any citrus fruit, but lemons or limes are usually included to provide some tartness, to cut the sweet quality. Aim for about half a cup of juice and at least four tablespoons of grated zest. This means about four limes, two small oranges plus one lemon, or one mammoth grapefruit plus a lime (and so on). Tangerines, blood oranges, key limes, and other more exotic citrus fruits will also work well.