After countless hours fussing over a holiday feast, you may see leftovers as liberation from the kitchen. But before you re-heat and eat that once-hot turkey, ham, sweet potato casserole or custard pie, you should know that they can make you so sick you might wish you were dead.
Food safety specialists explain that when cooked foods linger more than two hours at room temperature, they can become mess halls for colorless, odorless, tasteless bacteria.
You might suspect such dangers in meat or turkey, and you've probably heard that it's important to separate turkey from the stuffing when storing them. But what might surprise you is that even simple, starchy dishes like mashed potatoes enter a bacterial "danger zone" at temperatures between 40 degrees and 140 degrees Fahrenheit. At those temperatures, toxic bacteria can quickly multiply, stealing your holiday spirit -- and squashing your appetite.
Given enough warmth, nutrients and moisture, a single bacterium dividing every half-hour can produce 17 million offspring in 12 hours, according to figures cited by the Center for Science in the Public Interest.
Three particularly nasty microbes can hitch a ride on hands and steam tables, turning a Christmas or New Year's party into anything but a celebration, according to the U.S. Department of Agriculture's Food Safety and Inspection Service:
Staphylococcus aureus, which lives harmlessly on the skin and inside the nose and throat, frequently spreads through improper food handling. Cooking kills staph bacteria, but the toxin the bacteria produce are like action movie villains, withstanding heat, refrigeration and freezing temperatures to wreak havoc inside the intestines. The toxin attacks cells lining the gut, producing cramps and bloody diarrhea that may begin hours to days after you've swallowed the offending food.
Clostridium perfringens, sometimes called the cafeteria germ, is frequently found on cafeteria steam tables holding meat and gravy.
Listeria monocytogenes, often found in soft unpasteurized cheeses, thrives on cold buffet foods and continues multiplying inside refrigerators. Many people can be exposed without any health consequences, but this microbe poses peril to pregnant women, in whom it can trigger miscarriages, and to the elderly, who could land in the hospital after exposure.
In general, food safety experts recommend chilling leftover foods at 40 degrees or less, and re-heating them to at least 165 degrees to eliminate dangerous bacteria.
Soups should be heated to a rolling boil and stirred to heat throughout, advises Caroline Smith DeWaal, food safety director for CSPI, a consumer advocacy organization in Washington, D.C.
Food safety experts try to encourage good food-handling practices. DeWaal likes to invoke the following rule of thumb for holiday foods: 2 hours -- 2 inches -- 4 days.
2 hours is the maximum time a food can go from oven to refrigerator. "You take it out of the oven, you have your nice meal, but within two hours, you really need to be putting that food away and in the refrigerator," she said in a pre-holiday interview.
2 inches is the depth of containers you should use to quickly cool warm foods. That means dividing up big pots of soup, taking turkey meat off the bones and putting these into multiple, small containers.