How Long Does Canned Food Last?
by Tara Dodrill
How long does canned food last? Well, that will depend on several very important factors. First, there is a difference between the potential shelf life of home-canned fresh produce or meat and commercially canned food items – at least according to the United States Department of Agriculture – USDA.
As a general rule store-bought canned foods can remain edible for several years past the listed expiration date on the can, however, canned foods that are eaten past the listed expiration date may not have the full nutritional value as the same foods that are eaten before the given expiration date on the can.
There are several different varieties of “canned” food and date stamps applied to supermarket preserved food – both of these factors can make it very confusing to know when it is time to throw out the items stocked in your pantry. Fear of eating canned food beyond a date stamped onto a can accounts for about 20 percent of safe food waste in the United States annually.
Home Canned Food
The federal government (USDA) only considers home canned food shelf stable for up to 12 months and commercially canned food safe to eat for between two to five years – depending on the type of food inside the can.
Anyone who has been growing and canning food for a long time, or grew up eating home canned food from grandma’s garden, already knows most food canned from a backyard garden or farm is typically stored and eaten for far longer than 12 months. If properly canned and stored, many farmers, homesteaders, and preppers eat home canned meat and produce for up to five or sometimes even 10 years, after it was harvested – but the USDA strongly recommends against such a practice.
Just as with commercially canned food, it is essential to visually inspect the storage container for signs of cracking, damage, rust, or leaking – as well as the look of the food inside, before consuming any preserved food.
The answer to how long home canned food will remain safe to eat will vary widely based upon who you ask.
A can of corn discovered in 1974 and had been sitting on a basement shelf in California for 40 years was examined by scientists from the National Food Processors Association. The researchers found that the canned corn both smelled and looked like it had only recently been canned. Upon further review, the scientists also learned a few of the nutrients in the corn (vitamin C, in particular) had lower levels than freshly canned or in date corn.
When cans of peppers were unearthed from a steamboat that sank in Nebraska more than a century, extremely similar results to those found after reviewing the can of corn.
Will every home canned food item yield these same results? Maybe, maybe not. The USDA would not want you to eat anything canned in your own kitchen that is even a quarter as old, but learning how to can food properly, could make a life or death difference during a long-term disaster…and the extensive reconstruction phase which would follow.
Expiration Dates Explained
There are no true standards when it comes to the labeling of expiration dates of canned food, with the exception of baby formula. The expiration dates placed on cans is primarily intended for use by grocery stores so they know when to pull food from shelves because it is no longer guaranteed safe to consume beyond that date.
Some manufacturers use the term “expiration” others use phrases like “use by” or “best by” when stamping a date onto the bottom of a can. Once that relatively arbitrary dates passes, that does not necessarily mean the can most be thrown out and money lost. That date merely means the food is guaranteed to be safe to consume until the date stamp on the can passes.
Shelf Life Storage Factors
How the canned food, whether it is preserved at home or in a factory, is stored, will most likely have a vast impact on its shelf life. Canned food that is stored in a cool and dry place will almost always last a lot longer than canned food stored in a warm place that is exposed to even indirect artificial light or sunlight.
This is why tens of thousands of American used to routinely undertook the back-breaking work of digging a root cellar. The cool and dark storage area where the corn, tomatoes, and peppers noted above were found, almost certainly played a significant role in the incredible preservation longevity. Exposure to light also can diminish the overall nutrient quality of canned food.
While storing canned food in a basement should help it remain safe to eat long past the noted “sell by” date on the can, the placement location even in the underground storage area, is still substantially important.
If the home or commercially canned food is stored near a furnace or beneath pipes where hot water runs, it probably not last as long as the same food stored elsewhere in the basement away from the house utility features.
There are some drawbacks to both using root cellars and basements for storing canned food. If the canned food was not properly sealed, moisture from the typically damp location will infiltrate the food, forcing it to become either invisibly unsafe to out or quite visibly rancid.
Dampness causes the metal in home canned food or commercially preserved cans, to corrode and ultimately leak If the lid or any portion of the can is damaged or there is flaking in the lid, that might indicate acid has worn through the metal and permitted potentially harmful microorganisms to get inside.
If the lid of home canned food or any part of commercially canned food shows signs of rust, the contents inside are likely contaminated and no longer safe to eat. Before consuming any canned food past the USDA recommended guidelines, always inspect the food for signs of discoloration or unnatural changes in the texture of the food – this is actually a great habit to get into even when opening a can of food that is only a few weeks to months old.
Also review the color and texture of any broth, brine, or syrup the food is packed in to better detect signs of spoilage. I the liquid boast a musty smell or appears either opagu or “muddy” in color, that is a sure sign the canned food might no longer be safe to eat.
If liquid squirts out of the can upon opening, air and moisture have infiltrated the inside, making the food quite unlikely to still be safe to consume.
Should you still be unsure about the quality of the food inside a can after following the tips above, do a little taste test.
Dip a clean finger just slightly into the can and sample its contents. Hopefully, you would be able to determine if the food “tastes right” from past experience eating the same item. This test should only be used as a last resort during a disaster scenario when no other food was available and you were desperate to eat.
Impact Of Acid Content On Shelf Life
Canned food with a low acidic content can remain safe to eat approximately two to even five, years longer than food with a high acidic content. Foods that are high in acid contain vinegar. The same vinegar that helps to preserve the beneficial nutrients in the food cause them to decompose at a far greater rate.
Food with a high acid content should boast the crispest or fresh taste as well as the most nutrients for the first 12 months after being preserved, but they will not be shelf stable.
Therefore, home or commercially canned meat and fish could potentially possess a longer shelf life than many varieties of preserved vegetables or fruit.
Canned pumpkin, peas, carrots, potatoes, and soups as long as they do not contain tomatoes, should have a substantially longer shelf life well past the “best by” date stamped on the can or permanent marker date inked to the top of a Mason jar lid.
High acidic foods that will likely only be shelf stable or up to 18 months include all varieties of citrus, tomatoes, and pickles – due to the amount of vinegar in the brine used to make them.
Five Commercially Canned Food Items With Longest Shelf Life
- Hormel Spam. – This cheap processed meat product might not be a gourmet delight, but it is filled with protein, sodium, and “good” fats that should help your body strong during a long-term disaster. You could mix the canned Spam into soup or stew recipes to create more filling and energy building meals. How long will Spam keep? Some claim to have opened and safely eaten a can of Spam 10 full years after the expiration date stamped on the top of the can.
- Beef Stew – This is a low acid offering from the supermarket soup aisle because it does not contain tomatoes. It should safely keep, when stored properly, for about five years.
- Chunked Chicken Breast – The small cans of chunked or shredded poultry you would buy to make chicken salad also boast a low acidic count and are full of protein and sodium. This low acid canned food is typically expected to remain shelf stable for around five years when stored in a cool dry and dark place.
- Canned Chili With Beans – This protein-rich commercially canned food also possesses at least an average fiber count and when stored properly, can remain safe to eat for at least five years.
- Green Beans – Getting in your greens could prove to be both especially difficult and important during a doomsday disaster. Stocking up on green beans when they are on sale or adding a few more rows to your garden will increase your level of shelf-stable greens. When stored properly, green beans should remain safe to eat for at least five years but possibly seven.
Food Rotation System
To avoid the loss of food and the money it cost to either grow or buy it, use a simple food rotation process for all types of canned goods. The first can put onto the shelf should be the first one pulled out and used.
Food storage rack system made for commercially canned food are designed so you roll a can onto an upper ramp, forcing each can to be pushed toward the opening where it can be selected and used – first can in…first can out.