Leftovers and reheating: how to do it safely

The basic rules

• Refrigerate within 2 hours of cooking — or within 1 hour if it's above 90°F (32°C). Perishable food left out longer should be thrown away.
• Cool it fast: divide large batches into shallow containers so they chill quickly.
• Eat within 3–4 days from the fridge, or freeze. Frozen leftovers stay safe indefinitely, though quality drops after about 3–4 months.
• Reheat to 165°F (74°C), checked with a food thermometer — sauces, soups and gravies should come to a rolling boil.
• Microwaving: cover, stir or rotate, and let food stand before checking the temperature in several spots — microwaves leave cold spots.
• Thawing: thaw in the fridge, in cold water, or in the microwave. Food thawed in cold water or the microwave should be cooked before refreezing.

Cooked rice needs extra care

Uncooked rice can carry spores of Bacillus cereus, which survive cooking. If cooked rice sits at room temperature, the bacteria can produce a toxin that reheating won't remove.

• Cool rice as quickly as possible — ideally within 1 hour — then refrigerate.
• Eat it within 24 hours.
• Reheat until steaming hot all the way through, and only reheat it once.

Meat: watch the charring, not the reheating

Cooking muscle meat — beef, pork, poultry, fish — at very high temperatures, especially grilling or pan-frying above 300°F, forms compounds called HCAs and PAHs. To reduce them: avoid long cooking over direct flame, turn meat often, cut off charred bits, and consider partly cooking in the microwave first. Reheating cooked chicken to 165°F is the safe, recommended practice.

What about reheating spinach, eggs or chicken?

You may have seen warnings never to reheat these. Food-safety agencies don't say that. Like any leftover, cool them quickly, refrigerate within 2 hours, and reheat thoroughly to 165°F.