Check the jar from top to bottom. The Kerr name will be embossed on the glass. There are some general guidelines to approximate the date of a vintage Kerr jar between 1915 and 1930. The finish on a fruit jar can tell you roughly about the date it was made.

Are Kerr and Mason jars the same?

Standard Mason jars might be a bit small for this endeavor, however. If the Kerr jars and their packaging looks eerily similar to that of Ball jars, its because theyre basically the same: Both Ball and Kerr brands are now owned and manufactured by the parent company Jarden.

Do they still make Kerr Mason jars?

These jars are still in production, and will be a match to any Kerr Regular Mouth Self Sealing Pint that you can buy off the shelf.

How old is my blue mason jar?

Some helpful notes to keep in mind:Not every jar has their manufacture date on the glass, but most have the patent date. There will be a large number on the bottom of your jar. These charts tell you the approximate decade in which your Ball jar was made.More items •Aug 16, 2021