Wash 4 half pint jars and lids. Get all ingredients together, and prepare everything:

In a small bowl, whisk eggs and set aside. Wash lemons well, roll them under your palm to release the juice, then remove the zest using a fine grater, being sure you don’t get the white pith. Juice the lemons.

To cube butter, slice cold butter into 8-9 slices, then slice lengthwise. Roll butter stick and cut again, then separate the little cubes. Set aside. 

In a bowl (with kitchen gloves on), rub the sugar and lemon zest together.

In a heavy-bottomed saucepan, stir together the zest and sugar, and the lemon juice. Over medium-low heat, heat together, and gradually stream in the eggs. Stir constantly! Once the sauce is thick enough to cling to the back of a spatula or spoon, remove from heat. (When swiping a finger through the sauce on the spoon, the “line” should remain.)

Press through a sieve to remove all solids, then return to the saucepan. Heat gently, then stir in the butter and vanilla. Remove from heat, and allow to cool at least 10 minutes, stirring occasionally.

Spoon into half pint jars. If the lemon curd is to be frozen, make sure to leave plenty headspace for expansion. Thaw in the refrigerator before using.