If you like to make jam at home by yourself,you should pay attention to your jam jars and make them keep sealing to store the jam for a longer time. But when some of your jars failed to seal, what could you do to prevent them not sealing? Here are some tips for you:

    1.Use only standard canning jars. The glass in commercial jars (such as pickle or mayonnaise jars) doesn't have adequate lip thickness and thread depth needed for a good seal.

    2.Use a two-piece lid (flat and screwband). Do not use a one-piece lid as a substitute for a screwband. The ring may be re-used if it is not bent or rusty. Use a flat lid only once. Even mixing brands of flats and rings can cause sealing problems because of the design. Brand names are now stamped on the rings.

    3.Be sure the lip of jar is clean and not chipped.

    4.Follow headspace directions to avoid having liquid boil out of jars (siphoning) during processing. Headspace is the space between the inside of the lid and the top of the food. During siphoning, food particles in liquid may interfere with a seal. The ring (screw band) should be "finger tight" (tightened by hand) - not too tight or too loose. The band and lid are designed to let air vent from the jar during processing.

    5.Use jar lifter to remove each jar after processing so that the lid is not disturbed. Sealing takes place AFTER the jar is removed and starts to cool. Do NOT turn jars upside down.

    6.Be sure the correct processing time is used for the product being canned.