How are canned goods able to stay good for so long?


Just made myself a canned clam chowder, and really confused on why they’re able to stay good for so long.

I used to manage restaurants and it’s always confused me how my canned clams and clam juice, etc is fine sitting on a shelf for 6 months.

They’re not dehydrated, the can says to not add water. Ahh, please help lol

In: 11

The can is sealed (so no new air or cooties can get in), then it is heated up to kill anything inside that could make it go bad. So nothing inside can grow and nothing new can get in there to grow.

The environment the food is in is sterile, airless and airtight. Therefore, there aren’t any decomposers to make the food spoil, and there isn’t any oxygen to degrade the food. Before sealing, the food is usually passed through UV or heat, and preservatives are usually added. Sometimes the food is submerged in a liquid such as oil, water and sauce in order for the food to not be in contact with air and oxygen.

As an addendum to what others have said, the sterile environment in canned foods is extremely fragile. If there’s the slightest bit of damage on a can, toss it out, or you might end up getting a mouthful of botulinum toxin.

Met a couple who were cleaning a shed after their grandma passed away. They apparently found there a can from UNRRA post-WW2 relief effort. They opened it out of curiosity and the food looked edible, ~50 years after production. They obviously did not try to taste it…

There is also lots of home canning done in jars for fruit, vegetables and meat without having any preservatives or chemicals added. Although there are very specific requirements for the various foods involved. For example jars containing meat must be done in a pressure canner so it is hotter than 100 C/212 F and for several hours.