The Christmas dinner

About 1 pound each

Buy about 1 pound of whole turkey per person, which means a 12-pound bird for twelve people. Go up to 1 1/2 pounds each if you want sandwiches the next day. A boneless breast takes about 1/2 pound per person.

How big a turkey for 12 people? About 12 pounds, or about 18 pounds if you want leftovers.

1/2 pound bone-in, 1/3 boneless

The common figure is about 1/2 pound per person for bone-in ham and 1/3 pound for boneless, because you pay for the bone and nobody eats it. Guides run anywhere from 1/4 pound to 3/4 pound and up, mostly because some count one helping and others count seconds and sandwiches. If ham is the only main dish, plan toward the high end.

How big a ham for 12 people? A bone-in ham of about 6 pounds, or a boneless one of about 4 pounds. Go bigger if you want leftovers.

One rib for every two people

The usual way to order is one rib for every two people, which comes to about 1 pound of bone-in roast each. For boneless, plan on 1/2 to 3/4 pound per person. Ask for one more rib if you want cold beef sandwiches the next day.

How much does one rib weigh? About 2 pounds, so a four-rib roast runs around 8 pounds.

24 hours per 4-5 pounds

A 20-pound bird needs 4 to 5 days, so it goes in the refrigerator by Sunday, December 20. The safe faster way is cold water: keep the turkey in a leak-proof bag, allow 30 minutes per pound, change the water every 30 minutes and cook it as soon as it's thawed. Never thaw it on the counter.

How long for other sizes? Up to 12 pounds, 1 to 3 days. 12 to 16 pounds, 3 to 4 days. 16 to 20 pounds, 4 to 5 days. 20 to 24 pounds, 5 to 6 days.

165°F

165°F is the safe minimum, checked with a food thermometer in the innermost part of the thigh and wing and the thickest part of the breast. Go by the lowest number you read. Stuffing has to reach 165°F in the center too, in the bird or in its own dish.

If the turkey reads 165°F, is the stuffing done? Check it separately. The center of the stuffing has to read 165°F on its own.

145°F, then rest 3 minutes

Raw ham and beef roasts, prime rib included, are safe at 145°F with a 3-minute rest before carving. A fully cooked ham straight from its package only needs warming to 140°F. Any other cooked ham, such as one already heated once, goes to 165°F.

Is medium rare safe? Medium rare stops short of 145°F, so it doesn't meet the safe minimum. Recipes that call for it are going by taste.

2 hours

Cooked food can stay out for 2 hours, counted from when it comes off the heat. If the room is above 90°F, that drops to 1 hour. Food that's been out longer should be thrown out, even if it looks fine.

Does a buffet get longer? Not at room temperature. Food kept at 140°F or warmer, or 40°F or colder, is the exception. Some warming trays only reach 110 to 120°F, so check yours.

3 to 4 days

Cooked turkey, ham slices, stuffing and side dishes keep 3 to 4 days, so Friday's dinner is done by Tuesday. Gravy gets 1 to 2 days. Reheat leftovers to 165°F and bring gravy to a rolling boil.

How long does a whole ham keep? A whole fully cooked ham keeps 7 days in the refrigerator, half a ham 3 to 5 days, and slices 3 to 4 days.

2 to 3 weeks, airtight

Baked cookies keep 2 to 3 weeks in an airtight tin in a cool spot, and they don't need the refrigerator, though soft ones are at their best the first week. To freeze them, cool them completely, stack them with paper between the layers, seal and label the container, and thaw them in it at room temperature. Eat frozen cookies within about 3 months for the best flavor.

How long can cookies stay in the freezer? University guides run from 2 months to a year at 0°F. Past about 3 months they're still safe, but they taste less like the day you baked them.

Yes, if cooked to 160°F

Yes, if you cook the eggs and milk to 160°F, stirring the whole time, or start with pasteurized eggs. Raw eggs can carry Salmonella even when they're clean and cold, and liquor doesn't take care of that. Store-bought eggnog is pasteurized, but read the label to be sure.

How do I know it's reached 160°F? Use a food thermometer. The mixture will coat a metal spoon at about that point, and much hotter can curdle the eggs.