The clock and the danger zone
Bacteria multiply fastest between 40 and 140 degrees, a range the USDA calls the danger zone. Cooked food may spend no more than two hours there in total, and that window shrinks to one hour when the air is above 90 degrees. The clock starts when the food comes off the heat, not when dinner ends. For restaurant leftovers and takeout, it started when the plate reached the table.
Cool it quickly
A deep pot of soup or chili placed whole in the refrigerator can stay warm in the center for many hours. Divide large batches into shallow containers, two or three inches deep, so the cold reaches the middle. Carve a large roast or a whole bird off the bone before storing it. Hot food can go straight into the refrigerator, and there is no need to let it cool on the counter first.
How long it keeps
Cooked leftovers keep for three to four days in a refrigerator set at 40 degrees or below. That limit covers cooked meat, poultry, fish, casseroles, soups, pizza, and cooked rice and pasta. For anything you will not eat in that time, freeze it on the first or second day rather than the fourth. Frozen leftovers remain safe indefinitely and taste best within three to four months. Label every container with its contents and the date.
Reheat it properly
- Thaw frozen leftovers in the refrigerator, or reheat them directly from frozen, but never thaw them on the counter.
- Heat solid food to 165 degrees in the center, checked with a thermometer.
- Bring soups, sauces and gravies to a rolling boil.
- Cover food in the microwave, stir or rotate it halfway through, and let it stand for a minute so the heat evens out.
- Reheat only the portion you plan to eat, because each trip through the danger zone takes a toll.
Why the sniff test fails
The bacteria that make food smell spoiled are generally not the ones that make people sick. The dangerous ones usually give no sign at all, which is why the date on the tape matters more than your nose. Some bacteria, including one common in cooked rice left warm too long, produce toxins that reheating does not destroy. Reheating is not a way to rescue food that sat out overnight.
Note Anyone who is pregnant, over 65, very young or living with a weakened immune system faces the most serious consequences from foodborne illness. When cooking for them, keep strictly to the limits.
