Storing and reheating cooked food safely
Cool quickly, store cold, reheat hot. Two hours on the stove are the problem, not the third day in the fridge.
Bacteria multiply between 7 and 60 °C — the longer food sits in that range, the more. Leftovers should be in the fridge within two hours. A big pot cools faster in a sink of cold water or decanted into shallow containers. Warm food may go in the fridge — the “cool first” rule dates from the era of weak fridges.
In the fridge most dishes keep 2–3 days, rice and pasta only 1–2 (Bacillus cereus survives cooking and grows especially well in cooked rice). When reheating, at least 2 minutes at a rolling boil — and only once. Anything reheated twice is no longer good.
Mushroom dishes and spinach may be reheated despite the old rule — if they were cooled quickly and are heated only once. The nitrate problem with spinach is no longer one with modern fridges.