Beef stew leftovers will last up to four days in the refrigerator stored in an airtight container. In fact, as the stew sits, the flavors further develop, making for an extra flavorful beef stew! It's an excellent meal to make ahead of time too. Warm the leftovers in the Instant Pot or on the stovetop to reheat. For longer storage, transfer the stew to a tightly sealed container and place it in the freezer. It should last up to three months. When you're ready to serve it again, let the beef stew thaw in the fridge overnight and heat it back up in the Instant Pot or on the stove.