Whether your meatballs are fresh, refrigerated or frozen, there is a delicate balance between overcooking and undercooking. Overheated meatballs tend to be dry or rubbery while underheated meatballs may be cold or frozen in the center. The method used to heat the meatballs will affect the texture and flavor. You can also add heat to your meatballs with fiery spices.
Once cooked, meatballs can be refrigerated for up to 3 or 4 days. When reheating, you can microwave, bake or simmer in sauce. When microwaving, use a lower heat setting (between 50 and 80 percent) so you don't overcook the meat; a lower setting will warm them from the middle outward. The center will be hotter than the outside, so they may feel cool to the touch even though the interior is warm. Using too high a setting will produce dry, rubbery, chewy meatballs.
If reheating frozen meatballs in the microwave, use a paper towel or other microwave-safe drainer to catch excess liquid so the meatballs don't become soggy.
If baking to reheat, again use a medium setting, around 300 to 350 degrees Fahrenheit. While dry heat oven roasting cooks the balls from the outside in (the reverse of microwaving), high temperatures -- over 400 F -- overcook the exterior while leaving the center cold. Lower temperatures allow the heat to penetrate the meatball without drying out the exterior. Refrigerated cooked meatballs need only about 8 to 12 minutes in a 350 F oven, depending on diameter.
Since frozen meatballs take longer to warm, cook for 10 to 15 minutes in a 350 F oven, until the center reaches 165 degrees.
Simmering meatballs in a sauce is an effective way to reheat without drying them out. Place meatballs in a pot of sauce, cover and simmer over low temperature on the stove for 20 to 30 minutes. Do not let the sauce come to a boil.
If using a Crock-Pot, the meatballs will take longer to reheat, but can be kept warm by turning the pot to low after the meat has reached the desired temperature.
If reheating frozen meatballs using this method, remember that some ice may melt and dilute the sauce during the reheating process. Test the center for done-ness before serving.
Adding More "Heat"
If you want to liven up the fire level in your meatballs, add seasonings such as cayenne pepper, jalapenos or hot sauce to the ground beef. For spicy Italian meatballs, use spicy Italian sausage as your meat base. Lastly, use something fiery in your preparation, such as a hot sauce for Buffalo wings or hot mustard, to add spicy heat to your meatballs.