Canned tomatoes are very easy to keep on hand for that planned meal or spur-of-the-moment dish. Store unopened at room temperature in a pantry or food cupboard. Like most canned foods, they will store this way for up to one year.
Be sure to arrange your canned foods by the FIFO method (first in, first out) to help ensure you are using the product by the appropriate expiration date. Once the can has been opened, transfer leftovers to a glass or plastic storage container to avoid any metallic taste. Then store refrigerated for up to four to six days.
Another way to preserve your leftover sauces, crushed tomatoes or tomato paste is to freeze them in an ice cube tray. Once the food is frozen, transfer to a re-sealable plastic freezer bag. Use within six months.