Mould on home made jam

Linda32

Hello all,

I wonder if you could give me some pointers or to tell me that this "just happens" sometimes.

I opened a jar of home made plum jam tonight and it had a spot of mould on the top.

I made this last autumn, boiled to 220 degrees and checked for setting point using the cold plate method. Sterilized jam jars in warm soapy water and dried in oven. Potted jam into hot jars and sealed with wax disc and lid on whilst hot.

Kept in cupboard and when opened stored in fridge.

I've opened the two which were still in the cupboard tonight to find mould on the top. :eek:

Does this just happen sometimes or did I miss something?

Also one of the jams was very hard, I think this was due to over boiling. The reason this happened was that the jam reached 220 degrees very quickly, yet my Readers Digest Food from the Garden book says that it needs to boil for around 20 minutes.

I guess now I should have stopped when them temperature reacked 220 regardless of how long that took.

Thanks for looking.

Toxic_Lemon

I chucked out some HM strawberry jam today for the same reason! :eek: it looked like a scientific culture.

Stephen_Leak

I remember this from my grandmother's and mother's home made jam. You just scraped it off.

thriftwizard

Plum jam is notorious for developing mould. Have to say that I wouldn't risk it, but I'm allergic to some moulds.

Puddleglum

If there is just a little bit, scrape it off. Use your judgement about when a little bit becomes too much and jettison the jar. In practice it is very rare that a jar cannot be savaged.

Angela

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

[Deleted User]

I too remember just scrapimg any off when I was a little girl Rationing meant that we wern't quite so fussy as today.I know my Mum always said to use a seperate spoon for jam when sprreading and nevver ever put a knife in the jar as anything left on it even a tiny scrape of butter would spoil the jam.I must admit well over 65 years later I still use a spoon to get jam or marmalade out of the jar and onto the bread and never the knife.Old habits die hard

Linda32

Thank you all.

I did throw it away I'm afraid. I don't want to waste food, but I don't think its worth risking any health worries, or indeed necessary to consider the risk.

You have answered some questions though, thankyou. In as much as plum jam is known for it unfortunately we have a plum tree :T so it'll still have to be plum jam this year as well

Angela, I'm afraid I do not have a dish washer so I can't use that to dry them off. So it will have to be hot soapy water, and a hot oven for abit longer. I'll convert the 180 degrees to my gas mark as well as our oven is gas. I do realise that that won't make a difference its just that maybe I didn't have the oven hot enough.

I won't use a wax disk next time around though.

Perhaps you could help with the lid sizes, I did see a packet of spares in Lakeland but it was abit confusing as to the size of the lids for jars. The measurements didn't seem quite right for the sizes I had. Yet I'm sure the packet says it fits the size of jars that I have. Hope that makes sense.

lizzyb1812

This may not be the traditional way of sterilising but I wash everything, including reusing the lids, in very hot soapy water then fill the jars with clean hot water and put in a shallow dish in the microwave for a few minutes until the water has boiled over. Lids go in a jug and have fresh boiling water poured over them. No mould so far.

Buying new lids - take a jar with you next time.

Swan_2

JackieO wrote: »

I too remember just scrapimg any off when I was a little girl Rationing meant that we wern't quite so fussy as today.I know my Mum always said to use a seperate spoon for jam when sprreading and nevver ever put a knife in the jar as anything left on it even a tiny scrape of butter would spoil the jam.I must admit well over 65 years later I still use a spoon to get jam or marmalade out of the jar and onto the bread and never the knife.Old habits die hard

I always use a spoon for jam too, no buttery knives it's just horrible, in the same way that I don't like bits of coffee in my sugar bowl

I remember as a child when we had visitors, the jam would go into stemmed glass jam dishes & each one had an individual proper jam spoon


unless the mould had totally taken over, I'd just scrape it off & go ahead & enjoy the lovely jam

Linda32

lizzyb1812 wrote: »

Buying new lids - take a jar with you next time.

I took the lids with me. It did seem obvious as you said However, the Lakeland spares didn't seem to be the same size I could have taken the jar, but the lids were sealed in their packet anyway, so I couldn't have tried for fit.


Just to add, I don't stick the butter knife in the jam either. So its not that.

I think fresh new lids seem to be the answer, or plum jam being known for it.