Mould on home made jam

Farway

For the first time ever I had mould on my plum jam. I did scrapoe it off, but sampled a small spoon full, it tasted "off" so binned the two jars

No idea why this happened, other jars of same batch are fine, so can only put it down to jar sterilisation [low oven]

Valli

Angela wrote: »

I think your problem could be with the jars.
To sterilise you should wash thoroughly in soapy water,put in dishwasher then put in over for 15 mins at 180 degrees.
You must use new lids as you cannot sterilise old lids as you cannot get them to temperature without the plastic ring inside melting, you must use a new lid and you do not need a wax disc with jam, only lemon curd which doesnt need a lid to seal it,as soon as you have filled the jar with jam as far up to the top as possible put the lid on very tightly.
I cook for country markets(old WI market)and this is the correct sterilising and filling method and I have never had any mould on any jam or marmalade in 15 years of cooking for markets.
HTH

I have always washed jars out, then, prior to filling, sterilised in the oven. Always use old lids; as most of mine are the pop-up type as the jam cools they pop and seal themselves.

I was under the impression that if you have a dishwasher you need not sterilise (again) in the oven!

I have never yet had jam or marmalade go mouldy. I have kep HM jam for a couple of years; unopened, succesfully! And I make plum jam and damson jam (among others).

Mind you I know the WI would turn down my randomly sized jam jars!:rotfl:

OP it MIGHT be your plums - let me have a bagful and I'll check;)