Rubber Seal for Large Weck Lid (Food Safe)

Food Grade Rubber Seal for Large Weck Lids

Like all canning jars, the rubber rings and  glass lids of Weck jars need to be perfectly tear- and chip-free for the seal to become airtight.  It is always recommended that you use a new rubber seal every time you process a jar under heat (this does not apply to fermenting obviously as no heat is used)

It is easy to tell when Weck jars are successfully sealed. Canning jars seal after being taken out of the boiling water bath as they are cooling on the counter top. The changing temperature creates the vaccuum seal. 

If the jar is sealed, the tab on the rubber ring will be pointing down. Allow the jars to cool fully (preferably for 24 hours) before removing the clamps. Check again that the jar is sealed by lifting the lid. If it is sealed the lid will not lift off. If the lid comes of, either reprocess the jar, or put it in the refrigerator and seat the contents in a reasonable time period. 

Large suits the following models: 739, 740, 741, 742, 743, 744, 745, 748 and 974.  Large size is 100mm inner diameter, 110mm outer diameter.