How long can meatball stew be left in fridge after cooking?--Linda
A lot of factors can influence how long leftovers can be kept, but generally assuming that the food was properly cooled through the danger zone between 140°F (60°C) and 40°F (4°C), see How Long Can Cooked Food Be Left Out. It should be stored in the fridge within 2 hours total time since it was cooked. If both of these are the case, then, according to the USDA Food Safety and Inspection Service, the rule of thumb is the food can be kept safely for 3 to 4 days.
If food was left out too long, or was kept at a temperature within the danger zone longer than 2 hours, then the answer is that it is already spoiled, and should be thrown away. Now, I know that there are going to be people who say they hate to waste good food, and I invariably hear from somebody who claims to have an iron stomach, but the best motto is "When in doubt, throw it out!" You don't want to take chances with your health or that of your loved ones.
When reheating leftovers, they should be heated to at least 165°F (74°C). Sauces, soups and gravies should be brought to a full boil. If food is reheated in the microwave, it should be left to stand for 5 minutes or so to allow the heat to even out. Microwaves heat food unevenly so some areas may be above the 165°F limit while other places are still cold. Standing time helps to even this out.