Canned food is considered one of the most reliable types of food today. There have been many studies showing how canned food can last for decades and yet remain edible, with no traces of bacteria or microbial growth.
In some cases canned food as old as 100 years was still just as good and healthy as when it was canned. Of course, food loses some minerals and vitamins over time, and also the color isn’t as vibrant as when it was fresh, but the fact that it remains edible is what makes it so reliable.
According to some research results, frozen food can be considered just as nutritional as canned food. And while frozen food can’t necessarily remain edible for more than 40 years, this isn’t the case with canned food. Of course, we don’t recommend that you can corn and eat it in 50 years time, rather we show you that canning food can be a powerful way to store food for unfavorable conditions, emergencies or disaster events. We show you that even after the alleged expiration date is overdue, the food may surprisingly be unspoiled yet.
How long does canned food last?
We need to differentiate between commercially canned food and home canned food.
Commercial vs home canned food
So, usually commercially canned food, as we stated above, can last for many decades. This is true, of course, depending on how you store the food. According to research, if you store the canned food at a temperature around (or below) 75º F, it is possible that the food will remain unspoiled for possibly more than 100 years, and even indefinitely. This is provided that the can isn’t broken anywhere, punctured, etc. It must be intact.
Also, make sure not to freeze the canned food, as there may be risk of the food getting larger and breaking the jar/can. The optimal temperature range is 50-75º F.
You can see that certain canned foods are suspicious if the can is bulging. This may mean that some fermentation process is going on, and that there is microbial presence. You could open the can and inspect it yourself. As we recommend, use your senses (smell mostly) to determine whether the food is ok or not.
Again it’s worth mentioning that the longer you store your canned food, the more the color and texture will be changing. Don’t let that fool you. If you taste the food with the tip of your tongue and smell it, this should be enough to determine its properties. If you find it unpleasant, then it’s best to discard it.
When it comes to home canned food, the expiration date is usually much shorter. You need to be more careful when making your own canned food. This is because the process of canning is specific and requires certain conditions to be met. If the food you’re canning isn’t properly heated, a bacteria called Clostridium botulinum begins to grow. It causes botulism, which is a heavy form of food poisoning. According to data, large amount of patients in the United States suffered botulism because of improper heating of their home canned foods.
Apart from all that, home canned food should last up to 12 months. If stored in a cool and dark place, and if canned properly, the food can last about 1-2 years.
In those cases when you prepare your home canned food, adding certain preservatives can be a good start in prolonging its shelf life. Natural preservatives like elderly high acid, alcohol, etc. can bring some discoloration (if minor and only on the surface, that’s perfectly normal). Depending on what preservatives you’ve used the brine may (or may not be) muddy. It’s still important to note these things like muddy water, scum in the brine, bubbles, etc. The intensity of these indicators will show more clearly if there’s something fishy (no pun intended) in your jars.
If we need to compare canned vegetables, fruits and other plant food with canned meat, we must point out that canned meat tend to have a much longer shelf life. All that provided that you canned it properly. If it’s a commercial canned meat, according to some people the shelf life can be at least 7 years with the prospect of being virtually impossible to spoil.
All the above requirements of storage and can protection remain valid. It is also important to know that if you can meat at home, you must pressure cook it for as long as you pressure cook ordinary meat meals.
You should know that, for most commercially canned foods the expiration date doesn’t always mean that the food will be spoiled on the day after the printed date. Usually you may find on canned foods a ‘Best before’ date. This means that the flavor, taste and color of that canned food is best before that date. Practically ‘Best before’ dates are often simply suggestions for consumers, but they don’t indicated when the food will turn inedible.
This means that canned meat, for example, may have an average shelf life of 7 years, but have a ‘Best before’ date of 1 year after canning. It’s still perfectly edible on the 7th year. And as we already mentioned, its life is much longer if stored properly. According to most consumers SPAM’s canned meat can last forever if the can is not damaged in any way.
An example from real life is worth sharing. A British couple decided to marry in 1956. Among all the presents, they were also given a can of chicken. The man decided to set a game stating that on the couple’s 50th anniversary he will open the canned chicken and eat it. And so, in 2004 he kept his word and opened the can. He ate the chicken and liked it. It agreed with him just fine.
Canned plant food
According to labels and official information, canned plant food can last less than canned meat – about 2 years at most. Again, keep in mind that it can still be edible long after the ‘Best before’ date. The canned plant food will have best properties, highest mineral and vitamin value, and fresh taste and smell before the 2nd year. After that, the nutritional content will decrease with 10% every year. If the canned food is in jars and close to natural sunlight, the exposed areas may lose their fresh color.
Here is a real example of canned bread which survived the Second World War and was perfectly fine when first opened in 2002. It was found by an old man in Germany. He donated the 20 cans of bread to the European Bread Museum in Northern Germany.
The rye bread was carefully inspected and there were no signs that it wasn’t edible. This canned bread was perfect for human consumption even after 50 years.
Canned dairy products
Canned cheese and butter can also have a very long shelf life (just like the products we already mentioned). They can have an average shelf life of 5 years at least. According to one of the largest and most significant US food supplier the all-known ‘best before’ date of 1-2 years doesn’t come from the food itself, but from the can manufacturers. This is because even metal cans have some guarantee date.
After that date has expired, the can manufacturer can’t take any liability. Otherwise, after testing the microbiological flora in canned cheese and butter, the results are that the food is as good as new.
As for a real-life example, we can share that a food supplier employer had kept a 7-year-old canned cheese in his basement. He decided to bring it for inspection and it was discovered that the microbial content is normal and that cheese is edible.
The science of inspecting food
There’s a scientific establishment called National Food Lab. (NFL). You may be surprised to know that what they specialize in determining whether, and to what extent, the foods lose their taste, smell and looks. They taste foods at different stages after they were prepared – after 1 week, 1 month, 1 year, etc. They don’t eat it, but only taste. The verb is expectorate.
As they taste certain foods, they give them grades, from 1 to 10. As the food is deemed older, it is natural that the taste many not be as good any more, and they may give it 6. Yet, this doesn’t make it spoiled. It is only that they food may not be as tasty any more. So, as this data is processed and sent to food producers, they determine the ‘Sell-by’ and ‘Best-by’ dates according to how the experts from NFL had graded these foods. In this way food producers will protect their reputation by maintaining high quality of taste and smell for their foods.
The reason why we share this with you is to let you see into the process of labeling canned foods with ‘sell-by’ and ‘best-by’ tags. Most people believe that when the date has expired the food must immediately be tossed away, while it may be perfectly fine.
Keep in mind that if a canned food has ‘expired’ according to the date, it is sent to auctions or donated to food banks. It isn’t thrown away as stale.