A bit of interesting information about eggnog includes the origin of its name. The drink was originally called "egg and grog in a noggin", which was shortened to eggnog.
"In the 1820's Pierce Egan, a period author, wrote a book called "Life of London: or Days and Nights of Jerry Hawthorne and His Elegant Friend Corinthina Tom". To publicize his work Mr. Egan made up a variation of eggnog he called "Tom and Jerry". It added 1/2 oz of brandy to the basic recipe (fortifying it considerably and adding further to its popularity).
Eggnog, in the 1800s was nearly always made in large quantities and nearly always used as a social drink. It was commonly served at holiday parties and it was noted by an English visitor in 1866, "Christmas is not properly observed unless you brew egg nogg for all comers; everybody calls on everybody else; and each call is celebrated by a solemn egg-nogging...It is made cold and is drunk cold and is to be commended." - Egg Nog History
(Makes about 2 quarts)
6 large egg yolks (Make a batch of meringues with the whites!)
1/3 cup sugar
1/4 teaspoon salt
2 cups hot milk
2 cups cold milk
1/2 cup or more brandy or rum, optional (I just use 3 tablespoons of cognac as a flavoring)
2 teaspoons vanilla extract
1 teaspoon grated nutmeg plus more for garnish
1 cup whipping cream
1. At least nine, or up to 24, hours before serving time: In bottom pan of double boiler, heat an inch of water to a gentle simmer. In top pan of double boiler, whisk together egg yolks, sugar and salt until well blended.
2. Gradually whisk in hot milk and cook over hot but not boiling water, stirring constantly, until mixture thickens and registers between 160 and 170 degrees (but do not boil). Just pull a tall stool up to the stove like I do 'cause it's gonna take a while, about 15 to 20 minutes.
3. Stir in cold milk. Strain custard into a two-quart bowl; stir in brandy* or rum, vanilla and nutmeg. Cover and refrigerate until well chilled, at least 8 hours.
*Actually, you could leave out the alcohol and let each person add his own favorite tipple or have it alcohol-free.
To serve: Whip cream until soft peaks form. With wire whisk, gently fold whipped cream into custard. Pour eggnog into chilled 2- or 2 1/2-quart punch bowl or pitcher; sprinkle with nutmeg.
From: Eggnog, A Cup of Classic Comfort