Eli5 How can canned meats like fish and chicken last years at room temperature when regularly packaged meats only last a few weeks refrigerated unless frozen?

Question

Eli5 How can canned meats like fish and chicken last years at room temperature when regularly packaged meats only last a few weeks refrigerated unless frozen?

In: Chemistry

Answer 1

Bacteria needs a few things to grow. The canning process denies bacteria of some of these things while simultaneously sterilizing and totally sealing off contents.

Regularly packaged meats have some bacteria in them at relatively safe levels. Cooling the meat makes the bacteria grow very, very slowly, but it is still growing so you have to eat it before the bacteria eats away at the meat. Cooking kills the bacteria, which is why meat needs to reach a specific internal temperature to be safe.