How long will leftover food stay fresh in the refrigerator?

3 - 5 Days Leftovers must go in the fridge within two hours of serving to reduce your risk of food-borne illnesses, because bacteria grow more quickly at room temperature. Don't leave leftovers out. Put them in the refrigerator as soon as you're done with them. Cold temperatures slow the rate of bacteria growth. For larger items, such as large quantities of Chinese food, refrigerate in several shallow containers rather than large clumps. That way, the food will cool evenly and more quickly. You don't want a big clump: That risks the chance of something growing in the center because it didn't cool properly.