You Asked
How are air tight food cans made? Sonny, Dallas, Texas

Marshall Answered
The dictionary defines a “can” as “a sealed container for food, beverages, etc.” There are five types of “cans” that typically hold food and beverages today: Steel cans, aluminum cans, glass bottles and jars, plastic bottles and jars and retort packaging (things like juice boxes and MREs). The following video explains how aluminum cans are made for beverages:

How it’s made – aluminum cans

It’s a fairly involved process, but if you break it down to the fundamentals it has four steps:
1)Drawing out the can shape from a flat sheet
2)Thorough cleaning
3)Printing the label on the outside and plastic coating on the inside
4)Forming a neck at the top of the can

From there the can would be filled and then sealed with a lid. Whether you are filling a plastic jar with peanut butter or putting beer in a glass bottle…

…the process is the same.

You can do the same kind of thing at home. People who do home “canning” usually use glass jars with metal lids. The lids have a rubbery ring that forms an airtight seal with the lip of the glass jar. You put the food in, put the lids on and boil the jars to kill any bacteria. As the jars cool, the lids seal tightly. The food will last for a year or more in the sealed jar.