How to Date Old Ball Mason Jars

Dating old jars

Warning Only use a

Kerr used the patents to create a revelation in preserving food.

This means it would be

Look for a date of manufacture, job number, plant location and various other information. This means it would be post, during days of more efficient machines.

Warning Only use a Kerr jar lid once before disposing. Observe the finish of the jar.

Look for a

This would mean the jar is modern. Look for the Kerr name, which is embossed onto the surface. Kerr also founded the Hermetic Fruit Jar Company in the same year. San Francisco man Julius Landsberger patented metal lids fastened onto a composition gasket.