The recipe card is stained with butter and time. Your grandmother wrote it in pencil, then went over it in blue ink when the pencil smudged. “Nutmeg—fresh,” it says. “Don’t skimp.”

You separate the eggs the way she taught you, passing the yolk from shell to shell while the white drops into the bowl below. One yolk breaks, sending yellow streaks through the clear whites. You start again. The broken egg goes into tomorrow’s scrambled eggs.

The nutmeg grater is older than you are. Heavy and sharp, with a small compartment that holds whole seeds. The first scrape releases the smell—woody and warm and completely different from the pre-ground powder in the spice aisle. You grate it over the bowl until your shoulder aches.

An algorithm can generate an eggnog recipe in seconds. Temperature-controlled. Pasteurized. Safe. The eggs cooked sous-vide to eliminate risk, the alcohol measured precisely for flavor balance. No flecks. No memory of your grandmother standing at this same counter, humming off-key to a carol on the radio, saying, “A little curdle never hurt anyone.”

Heavy cream pours with a thick glug. Sugar dissolves slowly in the yolks. You whisk until your arm aches. A few threads of egg white cook instantly where they touch the warm bowl. You don’t strain them out.

You make it the night before. Cover the bowl with a tea towel. Leave it on the counter.

Christmas morning, the punch bowl sits half-empty on the counter. The nutmeg has settled into the cream like silt in a river. A spoon rests in it, still damp. The recipe card goes back in the kitchen drawer, ready for next year.