Making chutneys.Expiry dates.

Technically, in a sealed and sterlized jar, with the proper acidity and sugar, forever. But in your case... I would not trust it.

My MIL has jars of jam and preserves a few years old, like 5-6 years old, and it always gives me the heebeegeebees when she opens up a jar. So far no deaths yet. :)

..........They are stored in second hand jam jars which were sealed by tightening as much as possible by hand!

that violates pretty much everything about canning there is.
methinks you're on really thin ice there.

Unless you used regular canning jars with new lids (bands can be reused) I would not trust it. It really depends on the acidity/sugar level to prevent many types of food poisoning.

It's not the second hand jars that create an issue. I use my canning jars regularly. It's the lids that need to be replaced every time you can (not the rings, just the flat lids as these are what do the sealing. When you heat packed them into the jars did you use new lids, and did the lids seal properly? You can tell this by depressing on the lid, if it pops then they did not seal. If they don't pop and are slightly concave then you have acheived the vacuum that is required for proper storage. If you have followed those rules then the stuff should be safe. I have been eating jams made a couple of years ago, and even some pickles and haven't had an issue yet.

If you made a typical chutney with a vinegar/sugar ratio of 1/1, and followed proper canning procedures, I can't imagine there would be a problem. Also if the chutneys are on the thick side, that too would help to insure good shelf life, as there would be less available moisture needed by pathogenic microorganisms to survive.

notes: Anntinjou is playing with fire.

reading the original post:

[[heat packed and sterilised.]]
one assumes this means sterilized in a boiling water bath

[[They are stored in second hand jam jars]]
second hand jam jars are not 'reusable' canning jars -
[[several hundred jars]]
and these are all the same size, and all (as erroneously suggested) take a perfect fit to new lids?

[[sealed by tightening as much as possible by hand! ]]
if I'm reading this correctly, the jars were sterilized in a boiling water bath, the stuff poured in, the jam jar lids screwed on tightly by hand, and (assuming here) then processed in a boiling bath?
[[how long chutneys last depending on the sterilizing and bottling conditions.]]
and if this means they are not processed in a boiling bath, then:
[[have in stock 1 year old peach, apple ....]]
is not a good thing.

the purpose of a ring on a canning jar is to hold the lid sufficiently tight to exclude water in the boiling bath.
as the stuff heats up, air is expelled.
as the stuff cools down, a vacuum forms in the jar - sucks on the lid - the vacuum is proof of concept.

a tightly screwed on jelly jar lid may not allow air to escape, it may not (re)seal to promote a vacuum - no vacuum = no clue if sealed.

[[how would it be possible to detect if there was a bacteria problem if there is no visible or other evidence (such as the taste?)]]
somebody gets really sick, or dead.

One more thing.....

Never tighten the bands down to much after the water bath and cooling, as the action may loosen the seal on the rubber of lid.

Food Scientist

Provided that your heat processing was correctly done and that jar sealing is good, you shouldn't worry about bacteria. If stored under the conditions you specify, it will have a shelf life of a couple of years.