Keep cold foods cold and hot foods hot. If you’re serving a buffet, you can keep cold foods on ice to maintain a temperature below 40°F, and keep hot foods on a hot plate or sterno flame to ensure internal temperatures stay above 140°F.
As soon as your meal is over or within two hours (whichever comes first), place leftover food in the refrigerator. Allow hot or warm leftovers to cool in the fridge, not at room temperature.
Divide large amounts of leftovers into small portions. The smaller size will not only be convenient for leftovers, but shallow containers will allow for quick chilling.
Any leftovers should be covered, refrigerated and eaten within 3 to 4 days – or frozen up to 3 months. Reheat to 165°F throughout. Stir foods during reheating to be sure that all the food reaches the appropriate temperature.
When in doubt, throw it out. Never taste leftover food that looks or smells strange.
New Mexico Beef Council - Beef, It's What's for Dinner