Most non-perishable foods are safe indefinitely. In fact, canned goods will last for years, as long as the can is in good condition (without rust, dents, or swelling). Low-acid canned products, such as vegetables, canned meats and soups, should be eaten 2 to 3 years after their expiration date. According to the USDA, canned products with high acid content (tomatoes, citrus fruits, etc.) stable canned ham (such as spam) last 2 to 5 years on the market.
After opening it, it will usually be in good condition for 3 to 4 days in the refrigerator. Apples kept in a fruit bowl at room temperature generally last five to seven days. However, when stored in a humid place at a temperature of 30º to 40º F, they can remain crisp and fresh for up to six months. According to Candice Christian, a food safety expert for consumers and retailers at the North Carolina State University Extension, proper canning methods “remove oxygen, destroy enzymes in foods and prevent the growth of unwanted microorganisms.” Food canned at home doesn't have an expiration date, so it's always a good idea to mark the container with the date the food was canned.
If you're canning your own food at home, you should know that these foods will last up to a year on the shelf. However, since expired foods can decrease in quality, it's always a good idea to check with your local food bank or food pantry beforehand, especially if canned goods have expired for a significant period of time. The former public relations director of the Atlanta Community Food Bank says they do accept donations of expired food. In all cases, the estimated shelf life is for food stored at room temperature or slightly cooler, not in the refrigerator or freezer, which will substantially extend the shelf life of most items.
Tamika Sims, PhD, senior director of food technology communications at the International Food Information Council, says canned products can be safe and healthy to consume for years after their expiration date or better quality, but highlights that cans should be inspected for dents deep, swelling and rust. However, those dates actually have nothing to do with food safety, so they're not perfect indicators of how long canned foods last. The National Food Processors Association (NFPA) is a research group that studies topics such as expiration dates and food freshness. As long as your emergency food is food you normally eat, you shouldn't have problems with rotation.