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.
Rubber rings and lids are available singly or in larger packs. Note that the rings come in 5 sizes. The large size is 100mm and the number 100 will be embossed on the glass lid that suits these jars.
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 seals.
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.
Refer to the Weck chart to see what size rings you need for your jars.
Large suits the following models: 739, 740, 741, 742, 743, 744, 745, 748 and 974. Large size is 100mm inner diameter, 110mm outer diameter.
Ozfarmer Australia pleased to announce that we are now the Australian Distributor for the world famous Weck preserving jar. Weck Jars are known throughout the world as the best preserving jars on the market manufactured in Germany with the highest quality and German precision! These are also known as heirloom jars in Europe because they are so well made they tend to last forever.