WECK JARS: Weck jars are a German jar used throughout most of Europe and Asia and have increasingly become more popular within the United States as of late. Originally they were extremely hard to find in the States and even if you were successful at that, they were outrageously priced. Now it seems they can be found all over the place at a decent price. Weck Jars were invented to seal through the Water Bath Canning Method. This is where the jars are completely submerged in boiling water for a specific amount of time based on the contents and then left on the counter to create a vacuumed seal as it cools down. Note that due to the thickness of the jars, Weck encourages you to add an extra five minutes of processing time when canning with their jars.
Weck Jars come in all different shapes and sizes, but all jars are composed of the same basic elements. Here is a breakdown of a Weck Jar and the importance of each piece.
As shown above, Weck Jars are made up of four parts. The jar, lid, ring and clamps. Each plays a very important part in ensuring it seals properly after being processed.
RUBBER RING: The rubber ring holds the seal. It is designed to fit snugly around the lip of the lid (see above). It is best to fit the ring around the lid first and then place that combo on the jar. This ensures a good fit. You'll notice a tab on the ring. Pay close attention to this as it can be an indication of a good seal. After processing and cooling, the tab should face slightly downward as if the jar is somehow sticking its tongue out at you. Also, the tab is the only way to safely open the jar. Just place one hand around the lid and upper half of the jar and gently pull the tab away from the jar. You will hear the sound of air rushing into the jar.
Contrary to popular belief, the rubber rings can actually be used and re-used until they wear out or become defective in some way. Be sure to take care of them and check for wear and tear before using them to seal. Don't leave them in water or direct sunlight for long periods of time. This will cause the band to turn brittle and eventually break. Basically, the better you take care of them the longer they will last.
GLASS LID: The glass lid is what makes the Weck Jars so unique. You are able to see the contents of your jar from any angle and having such a beautiful lid makes the jar one to show off. Another benefit is that when processed correctly, the only thing your processed food comes in contact with is glass. Say goodbye to BPA forever! Now that's a topic for another day.
Lids come in three sizes. Small, medium and large based on the jars shape and size. So jars can stack and lids, rings and clamps can be kept separate. Lids of the same size- and rings for that matter- are interchangeable.
CLAMPS: The last thing to talk about and probably the most misused part of the jar are the clamps. It is important to understand that when canning with Weck, that the clamps should only be used when processing the food and then during the cool down period. After cooling you should take off the clamps. If a jar did not seal, you will know immediately as the lid will lift right off. Another reason to take the clamps off after processing is for safety. If bacteria in the food was not killed completely during processing, gasses will cause the lid to unseal as the pressure inside the jar equalizes to the pressure outside of it. This can happen any time as early as right after you canned- up to many months later. At this point, the lid and ring will sit loosely on top of the jar as if never sealed. If this happens, do not taste test the contents but carefully dispose of the contents of the jar. Be sure to always pull up on the jar lid to test the seal before opening a sealed jar for consumption.
