Whisk egg yolks and sugar in a medium bowl until fluffy and lightened in color. Set aside.

In a large saucepan, scald the milk. (Slowly heat the milk, stirring to prevent scorching as needed, until it just comes to a bare simmer with small bubbles forming around the edges of the pan.)

Gradually, bit by bit, add ladlefuls of the hot milk mixture to the egg yolks, whisking constantly. Return the mixture to the pan. Over medium-low heat, while stirring constantly, gently cook without boiling, until the mixture reaches a thick, foamy consistency, two to five minutes. The temperature should read 160 degrees F, but do NOT heat to over 165 degrees which will cause separation and curdling.

Strain the mixture. Refrigerate for at least an hour to cool.

Once cool add the cream, additional liquid of choice, vanilla, salt, and the 1/2 teaspoon nutmeg. Stir to combine. Place back in the refrigerator until flavors have blended and the mixture is completely chilled, overnight is best.

Note: this is not meant to be an especially thick eggnog; for a thicker eggnog, reduce the milk to four cups and increase the cream by two cups, or see my Rich and Creamy Eggnog on this site for another option.