These jars are often too brittle to withstand the heat treatment involved in canning and have a great likelihood of breaking during heat processing. They are best for uses other than canning. Pint and quart jars are the most commonly used sizes. Process 1 pints for the same time as quarts. Half-gallon canning jars are recommended only for very acid juices.
Jars also come in both the regular and wide-mouth styles.
If properly used, jars may be reused indefinitely. This type consists of a flat metal disc that has a sealing compound around the outer edge and a separate metal screw band. Do not use any old, dented or deformed lids or those with gaps or flaws in the sealing com-pound. These may not seal. Lids should be good for at least five years after manufacture.