I’ll admit this recipe isn’t mine; it has been handed down through Julia’s family. But I’ve inherited the role of make of the custard. No one else gets it as smooth and creamy as I do.
1 quart of milk
3/4 cups of sugar (not superfine)
5 large eggs
1 teaspoon of vanilla
Put the eggs in a bowl. Beat in about 1 cup of milk.
Mix remainder of milk and sugar in top of double boiler. If you don’t have a double boiler, you can fashion one by placing one pot inside another; the bowl over a pot method won’t work as well as there isn’t enough contact with the water.
Strain the egg and milk mixture through a cheesecloth and add to the milk and sugar mixture.
Put cold tap water in the bottom of the double boiler until it comes up the sides of the top pan at least an inch or two. I prefer to come as far up the top as I can without splashing water into the top.
Put the double boiler over medium heat (do not fiddle with the heat as the custard is cooking) and start stirring. Stir constantly until the mixture has thickened enough to coat a spoon when inserted. I find a whisk tends to work better than a wooden spoon for stirring.
Remove double boiler from heat and add vanilla. Stir.
Sounds simple? It is. There are, however, two tricks to this recipe. First, the egg and milk mixture must be complete strained of the eggy lumps created by the yolk membrane and the chalazae (the strands of albumin that keep the yolk suspended in the center of the egg). Toward the end of the straining, you will need to squeeze the cheesecloth to get the last of the non-lumpy mixture through.
The second trick is patience — the patience to bring the custard up to temperature slowly and the patience to stir it constantly. Custard thickens through the coagulation of the proteins in the milk and egg as they heat up. Starting with cold water is important so the mixture has time to come up in temperature slowly and evenly. If the proteins coagulate too quickly, the mixture is lumpy. Stirring the mixture constantly keeps circulates the warmed custard mix through the entire batch. It also prevents the proteins from forming lumps in the mix and from sticking on the bottom and the sides of the pan. If the mixture isn’t stirred enough, it can be a little grainy. My custard (usually a double or triple batch) takes from 1-1/2 to 2 hours to thicken.