A Mason jar is a molded glass jar used in canning to preserve food. The mouth of the jar has screw threads on its outer perimeter to accept a metal ring (or "band").

 

The Mason jar was invented and patented in 1858 by Philadelphia tinsmith John Landis Mason (1832-1902). Among other common names for them are Ball jars, after Ball Corporation, an early and prolific manufacturer of the jars.

 

Need them to preserve home-made jams, pickle, spices and my Korean kimchi!

 

Blue Ball Heritage Mason Jars

 

Most antique jars that are not colorless are a shade of aqua known as "Ball blue," named for the prevalent jar maker. Colored jars were considered better for canning use, as they block some light from reaching the food, which helps to retain flavor and nutritional value longer. 

 

Buy them here.