Tool: Mason Jar
A Mason jar, created in the early 1850's by John L Mason, is a glass jar used in home canning to preserve food. They are also called Ball jars after the Ball Corp, a manufacturer of the jars. They are also referred to as fruit jars because they are often used to preserve fruit, and sometimes simply glass canning jars. Today, these terms often specifically refer to jars with a two-piece cover: a flat metal lid (with a seal on the inside lip), and a screw on metal ring which tightens on the lid. The loosely placed ring holds the lid in place during the canning process, creating a vacuum allowing air and steam to escape, and sealing the lid to the jar.
The jars are made of soda-lime glass and are available in various sizes such as, quarter pint, pint, half pint, quart and gallon, as well as regular and wide-mouth.