While the can has worked its magic to help preserve the food contents inside it for all this time, once the seal is broken, air seeps in and highly acidic foods (eg, fruit, tomatoes) like to cling to the tin, iron and aluminum within the can, also known as metal leaching, per Science Notes. While this won’t raise health concerns and the food inside the can is completely safe to eat stil, it will present an “off” tinny flavor and make for less enjoyable leftovers. If you’re stuck at the office with a lack of resources, it’s best to cover the opened can with plastic wrap instead of the metal lid, which will help to reduce the metallic taste. However, sealable glass or plastic storage containers are preferred.
When cooking at home and racking your brain trying to figure out what to do with those stubborn canned ingredients you only needed a little of, the freezer is your friend. In fact, there are so many freezer hacks out there for leftover canned foods — some of which include Martha Stewart’s huge save for tomato paste or POPSUGAR’s ice tray hack for pumpkin puree — you should have little trouble finding a storage solution for your own opened canned food, because let’s be honest, you probably won’t end up using it all up in time (within the USDA’s three- to seven-day refrigeration timeline).