Eggnog really makes you wonder: How did humans first think chugging a spiced and spiked egg-yolk-and-milk mixture was a good idea? It’s a bit like Gaston from Beauty and the Beast: “Now that I’m grown, I eat five dozen eggs, so I’m roughly the size of a barge!” Yet despite its “love it or hate it” fame, eggnog has charmed drinkers for nearly a millennium.

While culinary historians debate its exact lineage, most agree eggnog originated from the early medieval Britain “posset,” a hot, milky, ale-like drink. By the 13th century, monks were known to drink a posset with eggs and figs. Milk, eggs, and sherry were foods of the wealthy, so eggnog was often used in toasts to prosperity and good health.

Eggnog became tied to the holidays when the drink hopped the pond in the 1700s. American colonies were full of farms—and chickens and cows—and cheaper rum, a soon-signature ingredient. Mexico adopted the very eggnog varietal “rompope,” and Puerto Rico enjoys the “coquito,” which adds coconut milk. The English name’s etymology however remains a mystery. Some say “nog” comes from “noggin,” meaning a wooden cup, or “grog,” a strong beer. By the late 18th century, the combined term “eggnog” stuck.

Eggnog purists argue that those who don’t like the Yuletide drink have simply never tasted the real thing. Sugar-laced supermarket versions can’t hold a candle to the homemade goodness, especially since the US Food and Drug Administration permits that the drink can be made from as little as 1% egg yolk. That often borders on “milknog” or egg flavoring.

Our founders would have had none of that. George Washington even penned his own famous heavy-on-the-alcohol eggnog recipe. Only one problem: he forgot to record the exact number of eggs. Cooks in his era estimated a dozen would do:

One quart cream, one quart milk, one dozen tablespoons sugar, one pint brandy, 1/2 pint rye whiskey, 1/2 pint Jamaica rum, 1/4 pint sherry—mix liquor first, then separate yolks and whites of eggs, add sugar to beaten yolks, mix well. Add milk and cream, slowly beating. Beat whites of eggs until stiff and fold slowly into mixture. Let set in cool place for several days. Taste frequently.

So as you enjoy your holiday cheer, please drink responsibly. Not just for the alcohol, but also for the calories: eggnog can pack in upwards of 400 big ones per cup.

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.