Three-day-old leftovers are generally safe if they were chilled within 2 hours and kept properly cold, per FDA guidance.
Divide big batches into shallow containers for fast cooling, reheat once to steaming hot, 165°F, and bring soups and gravies to a boil. Tighter clocks apply to some foods: cooked rice within 24 hours, and seafood and cooked meats within two to three days. Smell and looks are only backup checks; slimy, sour, or fizzy means out regardless. Take only the portion you will eat rather than reheating the container repeatedly.
What to do
Common questions
Is it safe to eat leftovers after three days?
Three days is generally fine if the basics were done right, and day four is where caution rises. The safety of a leftover is decided less by the calendar than by two things: how fast it got cold and how cold it stayed. The FDA's rule is to refrigerate perishables within 2 hours of cooking, or within 1 hour if it is hot out, and to divide large amounts into shallow containers so they cool quickly. A stew that sat on the stove all evening is a day-one risk; one that went into a cold fridge fast is a day-three lunch. When reheating, the FDA says bring sauces, soups, and gravies to a boil, and get leftovers to 165°F, steaming hot throughout. Some foods have their own tighter clocks: cooked rice should be eaten within 24 hours per UK food safety guidance, and seafood and cooked meats are best within two to three days. Trust the test senses only as backup: smell and looks miss plenty of bacteria, but anything slimy, sour-smelling, or fizzy is out regardless of dates. The one-way rule helps too: reheat once, not repeatedly, taking only the portion you will eat. When genuinely unsure, the cheap option is binning it, because food poisoning costs more than a replacement lunch.