Jars

Jars are closed containers, typically cylindrical vessels with a mouth at the top, used for storage, preservation, and serving. They are most commonly made of glass, but can also be metal, ceramic, or certain plastics. Glass jars are valued for being non-porous and chemically inert, helping to protect contents from contamination and odor transfer.

Common types include general-purpose storage jars, spice jars, and jars designed for preserving foods such as jams, pickles, and sauces. For food preservation, jars often use a two-piece metal lid with a flat disk and a screw band, forming an airtight seal during processing. Jars come in a range of openings, including wide-mouth and regular-mouth designs, to accommodate different contents and uses.

Sizes vary widely, with common household options including 4 oz, 8 oz, 12 oz, 16 oz (a pint), and 32 oz (a quart). In metric terms, equivalents range roughly from 100 ml to 1 liter. Jars have a long history in food preservation, and modern home canning jars were popularized in the late 19th century by John Landis Mason.

Uses extend beyond preservation to include dry storage (grains, coffee, spices), portioning, beverages, and decorative or display purposes. Care and safety considerations include dishwasher compatibility for glass jars and appropriate handling of lids during heat processing to prevent seal failure. Environmentally, jars are reusable and recyclable, contributing to reduced disposable packaging when reused for storage or repurposed. See also packaging materials, food preservation, canning, and container.