The simple answer is you can reuse canning jars but lids may not seal properly when reused.
The simplest questions are sometimes tricky to answer because while it may seem obvious things aren’t always so simple in practice.
Reusing Canning Jars
Reusing canning jars is fine and they have an indefinite life as long as they are not chipped or scratched.
You still need to keep them clean and make sure they are sterilized before each use but once you have the jars they can be used again and again.
Reusing Canning Lids
The two-part lids that are used with canning jars are not so simple. The disk part of the lid is not reusable.
You will probably have noticed that the disk part of the lid is sold without bands and come in large packs. This is because they are designed to be replaced after every use.
Canning jar lids comprise a band that actually screws onto the jar and a disk that sits on the mouth of the jar.
The bands of the lids can be reused as long as they aren’t bent or rusty. The disks cannot be reused as the gaskets that are on the underside that form the seal are only designed to seal once.
When you can your preserves in a hot water bath or pressure canner the gasket on the lid becomes soft and flows to seal the mouth of the jar in a sense deforming to fit exactly over the mouth of the jar.
Once cool the gasket hardens forming a completely airtight seal.
If you then come to reuse this lid the gasket may fail because it is not completely smooth and may even have a depression from the initial seal.
Of course, if the jars don’t seal completely airtight your batch of preserves will spoil and need to be discarded.
Replace The Lids Each Time You Water Bath Or Pressure Can
If you are canning in a hot water bath or pressure canning then replace the lids.
Suppliers sell packs of the disks at really reasonable prices which means you can reuse the jar and the band and simply replace the lid and have a brand new fresh gasket.
What Can You Do With The Old Lids?
The lids while not being able to seal for long-term canning can still be used for storage.
If you are making refrigerator pickles or quick pickles that are eaten within a few days or a week then they are perfectly usable.
Used for storage they are fine but long-term preserving will require fresh new lids.
Is There A Reusable Canning Lid Available To Buy?
If you don’t like the idea of waste and having to replace the lids of your canning jars all the time what can you do?
There are now suppliers of reusable canning lids but they are slightly more expensive than regular lids but, of course, you can use them time and time again.
These reusable lids come as a disk with a rubber gasket that is separate from the lid. You will need to use your own bands for the jars. The disks can be used in a regular hot water bath or a pressure canner.
If you are concerned with the waste of having to replace lids every time you can a preserve then these reusable lids are definitely an option worth investing in.