how long do they keep? preserves, chutney etc

[gregorach]

If you are regularly getting mould in your jam - either you are not boiling it long enough or you have not sterilised your jars & lids properly before filling and haveintroduced contaminants.

As the "microbiological pedant" (Thanks MKG! ), I feel I should point out that unless you're running everything through a proper autoclave cycle and filling your jars using laboratory-style aseptic handling techniques, you haven't sterilised your jars & lids at all and almost certainly have introduced contaminants. Your jam isn't really sterile either. Pressure sterilisation of the whole lot once the tops are on is the only way to actually achieve sterility in anything bottled, canned or jarred at home.

On my most recent check, a 100mm sterile wort agar plate simply exposed for 60 seconds in my kitchen developed 11 mould colonies. Even using my best sterile handling techniques I can't guarantee avoiding contamination when I'm propagating yeast, and that's a lot more controlled than making jam.

Now, of course, having said all that... Jam is not a hospitable environment for most organisms, so you don't actually need to worry about laboratory-grade sterilisation and sterile technique. I just get twitchy when people throw the word "sterile" around, and I guarantee that you do have some mould spores in there.

My jam seems to keep OK though...

[Marmalady]

Did I ever mention I used to run a factory making preserves for independant and multiple retailers? ( yep that stuff you see for £4 for a pot of Jam with "dave's deli from Dagenham" on the lid, and those pots of chutney with a cheese board for £15 in T&sco at Christmas, that was me)

and i, on the other hand, am a one-woman business successfully selling truly home-made preserves for over 20 years

If you are regularly getting mould in your jam - either you are not boiling it long enough or you have not sterilised your jars & lids properly before filling and haveintroduced contaminants.

As the "microbiological pedant" (Thanks MKG! ), I feel I should point out that unless you're running everything through a proper autoclave cycle and filling your jars using laboratory-style aseptic handling techniques, you haven't sterilised your jars & lids at all and almost certainly have introduced contaminants. Your jam isn't really sterile either. Pressure sterilisation of the whole lot once the tops are on is the only way to actually achieve sterility in anything bottled, canned or jarred at home.

On my most recent check, a 100mm sterile wort agar plate simply exposed for 60 seconds in my kitchen developed 11 mould colonies. Even using my best sterile handling techniques I can't guarantee avoiding contamination when I'm propagating yeast, and that's a lot more controlled than making jam.

Now, of course, having said all that... Jam is not a hospitable environment for most organisms, so you don't actually need to worry about laboratory-grade sterilisation and sterile technique. I just get twitchy when people throw the word "sterile" around, and I guarantee that you do have some mould spores in there.

My jam seems to keep OK though...

well yes, unless you really want to make your jam in a laboratory there will will air-borne contaminants around. But, as you say - jam does not easily support such organisms so anyone who is regularly getting mouldy jam has done something wrong somewhere along the line.

I still maintain that properly made & stored preserves do not need the extra sterilisation process - but you can do it if you want!

[boboff]

What confuses me somewhat, is that you think your way is "proper" and that everyone else is not.

The hot fill method you use does base itself on some rather complex science, and indeed it is effective provided you fill above 70c, and your Ph is right. The fact that you boil the arse out of the pulp helps as well. The fact the product has enough latent heat to kill bacteria and mould when sealed does the job, the Ph is important to prevent any spores gowing into bugs when cooled.

My nans been making "truly home made preserves" for the last 65 years, and some of hers go mouldy, some taste shite, lots however are nice. What you can't afford when you do sell your products is a mistake, and a product recall, the pastuerisation, or strictly speaking apertisation process reduces this risk considerably. It properly does.

Anyway, whats to say, I don't run a factory anymore, you still make your preserves without pastuerising, and you are happy, I am happy. A forum is a place of different views, and long may it continue. Properly.