HM jam going mouldy - what am I doing wrong?

safetygirl

I am not a home jam maker but consult in food hygiene so; if you didnt use a lid that could be sealed, the wax disc would not have prevented air getting into the jar and jam and thus cross contaminating the product. You would have got some airborne ( ie bacteria that are already in the air) in there and also some mould spores. Mould shows on the surface of a food, but its 'spores'can extend beyond and into the product, so taking an extra layer off was a wise precaution. Sugar is an 'inhibitor' for bacteria and mould, but is only a tenth as effective as its equivalent weight of salt (I am not suggesting you use salt in jam making!) Mould grows and spreads far more easily and quickly than bacteria, but it worth noting that some bacteria can only grow in anaerobic conditions i.e. those where there is no oxygen or air at all -just like the conditions you are creating in a sealed jam pot. These anaerobic bacteria can cause nasty food poisoning so be careful. i think the cellophane covers and proper fitting lids, plus the 'sterilisation' methods that others mention above are very viable for removing and killing off mould and bacterial contaminants (bacteria are ONLY killed by high temperatures, cooler and frozen temps only slow down or stop them multiplying). Alcohol is also an inhibitor. It is worth remembering that the commercially made jams will be full of preservatives etc., to prevent mould growth. It is also worth mentioning that home made jams once opened will not last very long at all as once opened, the seal has been broken and therefore all the airborne bacteria etc., will be getting into the jam. Finally, the good news is - is that mould growth will usually occur before any nasty bacteria get a grip on the food, so take mould growth as an indicator (like you did) that something is wrong and react accordingly

:beer:

katyboo123

Hey there, I have made four batches of jam now and following Delia's Ten Steps to Jam making http://www.deliaonline.com/how-to-cook/preserves/ten-steps-to-jam-making.html

It seems that these tips and techniques all work - so don't presume you're going to have to throw it away...

"if mould develops on the surface of jam in a jar, remove it with a spoon, along with about half an inch (1 cm) of the jam underneath – rest assured, the rest of the jam will not be affected – and place a waxed disc dipped in brandy on top"

Nom!

PS I think it sounds as though you are doing everything that I have done, so maybe it's just the lids situation. I have used waxed discs alone, but then I added a cellophane circle and elastic band to ensure it was air tight. No mould developed at all! Good luck xxx

tinateaspoon

I've just made some pumpkin jam and having read through the above, bit worried that the cellophane on some of the jars hasn't dipped down in the centre. So presume not sealed properly, can I try resealing now the jams cold?

Hopeinhell

I make jam a lot, but always find I need to boil it much longer than recipes say in order to set properly. Don't use wax circles, reuse old jars with their lids but sterilise both these in the oven for 20 minutes at 120 degrees C. Then fill jars straight away with hot jam, leave a few minutes and put on lids. Then.. store jam in fridge. Use in date order.

shop-to-drop

Just wanted to add (not sure if said already) but don't through away the jam. Spoon off all the mouldy jam and use the rest keeping it in the fridge. It's probably only the top layer that is moudly.

grandma247

I do my jams the American way. The jars have metal lids and the filled jars are placed in a deep pan with water covering them for at least two inches above the lids. They are then brought to the boil and boiled for the time they need. Google boiling water bath canning. I have never had a failure and the jam keeps for a long long time in good condition. The lids can be re- used several times. Make sure your fruit is not too overipe.

janb5

Hi- if anyone would like it I have a copy of the Daily Mail`s " booklet How to Make Jam" which I havent used. If anyone would like it please pm me and if you send me a sae I`ll send it to you :A. If I get lots of replies...and there is only one..I`ll pick one at random.

jscrooge

I make jam with no added sugar at all. The trick is to make one jar at a time, keep it in the fridge and consume it within 10 days in winter or 5 days in summer before it has time to go mouldy. A very easy way to make it is to cut the fruit in chunks and microwave it in a microwave pressure cooker ( basically a plastic tub with a closeable aperture) for 3 minutes on full power then 5 minutes on half power. Then mash it with a fork. If using soft fruit remove one or two tablespoons of juice so the product will not be too runny. Then add a tablespoon of heat surviving artificial sweetner (sucralose is one) and the juice of one lemon. Microwave again on full power for 2.5 or 3 minutes then spoon into a sterilised jar, lid it and leave to cool. The jam will be pure fruit lowish calorie and of a soft texture unlike solid supermarket jam which contains up to 50% added sugar and sometimes chemical colour and preservative. With imported fruit available all the year round this easy jam can be made anytime and if used as above rarely has time to go mouldy. I don't add alcohol to jam but do use it to bottle whole fruit putting as much fruit as possible in a jar then topping up with vodka. I read once that adding a vanilla pod to the alcohol bottled fruit produced a nice result. The only home preservatives I know of are sugar,alcohol.salt,vinegar and possibly acid fruit juice. If anyone knows any artificial preservatives suitable for home use that would be useful information as diabetic jam sold in supermarkets contains about 25 -30% sugar some of it as fructose instead of sucrose or glucose syrup but still sugar.