Food Safety
About product dating
Except for infant formula and some baby food, product dating — having a "use-by," "sell-by," "best-if-used-by" date — is not required by Federal regulations. Dating is for quality, not safety. However, if a calendar date is used, it must express both the month and day of the month (and the year, in the case of shelf-stable and frozen products). If a calendar date is shown, immediately adjacent to the date must be a phrase explaining the meaning of that date, such as "sell by" or "use before." While there is no uniform or universally accepted system used for food dating in the United States, dating of some foods is required by more than 20 states. A shelf-stable product can be safely used after the "sell-by" date. Products displaying a "use-by" date, although still safe, may not be of acceptable quality after the "use-by" date.
Will commercially canned foods last forever?
Commercial canning is done under tightly controlled conditions — careful sanitation and the necessary time and temperature under pressure, but there are still limits to how long it will preserve food. There are several factors that limit the shelf life of canned foods. First, cans can rust over time. Shipping accidents, where cans fall and dent or are crushed, also cause container problems. Then there's can corrosion. In all foods, but especially in high-acid foods like canned tomatoes, natural chemicals in the food continually react with the container. Over several years, this can cause taste and texture changes, and eventually lower the nutritional value of the food. High temperatures (over 100 °F) are harmful to canned goods too. The risk of spoilage jumps sharply as storage temperatures rise. In fact, canned goods designed for use in the tropics are specially manufactured. Store canned foods and other shelf stable products in a cool, dry place. Never put them above or beside the stove, under the sink, in a damp garage or basement, or any place exposed to high or low temperature extremes. Temperatures below 85 °F are best. Check your pantry every few weeks and use canned goods you have had on hand for awhile. Don't use bulging, rusted, leaking, or deeply dented cans.