Why Does Canned Food Not Spoil?

Canned food is one of the most popular and convenient ways to store and consume food. But have you ever wondered why canned food is so shelf-stable, and why it doesn’t spoil? It all comes down to the process of canning and the materials used to make cans.

The process of canning starts with the selection of fresh, healthy ingredients. The ingredients are then thoroughly cleaned, cooked and sealed in a can.

This can is made from either tin or steel, both of which are non-porous materials that provide an airtight seal. The airtight seal prevents bacteria from entering the can and spoiling the food inside.

The cans are then placed in a special machine called a retort or autoclave. This machine heats the cans for a specific amount of time at temperatures ranging from 121°C to 131°C. This heating process kills any bacteria inside the cans and also creates an even tighter seal.

Finally, the cans are cooled down quickly using cold air or water, which helps preserve their contents for longer periods of time. By keeping out oxygen, light and moisture, canned foods remain safe to eat for months or even years in some cases.


Canned food does not spoil because it goes through an extensive process that involves cleaning, cooking, sealing and boiling before being cooled down quickly. This process eliminates bacteria from entering the can while also creating an airtight seal that keeps out oxygen, light and moisture which would otherwise cause spoilage.