A Jam question

[hippolyta]

I had a glut of rhubarb so decided to make jam. Never made any before.
It's turned out delicious, slightly runny but that's not the problem.
I only found out afterwards that you are supposed to fill the jars to the top. I had an assortment of odd jars and have left big gaps. Also no wax toppers. Is it all going to go mouldy? Can I do anything now?

Was it hot when you put it in the jars? If so it'll be ok but use the one with less in first. I've been making jam for 30 years and never used wax paper!

You could tip one jar into the others to fill to the top and exclude the air?
Have you got greaseproof paper, cling film, any of that you could substitute for wax paper rounds.

And /Or store it in a very cool place.

Nb it's probably runny as rhubarb doesn't have much pectin, which is the setting agent. You could (next time) add pectin, use jam sugar which has pectin added, or add in some fruit which is naturally high in pectin. Gooseberries, currants, lemon rind and pips (but fish this out when done!), unripe plums, quince, crab apple etc. Depends what time of year it's and what's about!

I don't use wax paper either, but I DO 'sterilise' everything and fill to the top. And use airtight- ish jars.

Did you sterilise the jars and was the jam hot when you filled them? Is there a vacuum seal on the jars?

If the answer to all those is yes, then my part filled jars have always been OK.

If you sterilised the jars it will be ok but use least filled one first.
Love rhubarb!

Thank you.
I did sterilise the jars and lids and the jam was hot when it went in.
The recipe I used was without pectin, I knew it wouldn't be a firm jam and that's fine. It spreads lovely on bread.
I'm just worried that there won't be a vacuum seal because of the gap.

I can't believe I'm 64 and I've never made jam before, it was so easy. I remember my mum and grandmother making jam and always seemed such a drama.

You should be able to tell if there's a vacuum seal for the screw top jars with the dimple in the jar lids. As the contents cooled, it should have created a partial vacuum and pulled the dimple down - if you're around you can here them pop.

For the clip jars, if you undo the clip part if there is a vacuum seal the lid will stay down, if there isn't the lid should pop up slightly.

I can't tell what type the front right jar is, it almost looks like a plastic lid?

I would keep them in the fridge and use quickly.

The jar on the right with a plastic lid probably won't be airtight so use that first.

If you sterilised the jars and lids before filling, all should be well.

To sterilise jam jars ; wash in hot soapy water (even if they were put away clean) then rinse. Stand them in a roasting tin in an oven at 100, while the jam cooks.
Meanwhile, boil the lids in water in a saucepan, drain and cover with a clean tea towel.
When you're reasdy to pot up, get the jars out of the oven and stand them on a newspaper (easy clean-up after) Fill jars and lid straight away.

My DH make rhubarb and ginger every year. We clean the jars in the dishwasher and fill them pretty full. The jam always keeps well.

The reason it is a drama is that it needs to boil on a rolling boil for a time to get to the right temp for the sugar to be cooked enough for it to set. And then it needs to go into sterilised jars which are also very hot. If you boil it too much then it can set too much.

If you have made a non-set, runny jam, you might not have got it to that temp and this may mean it will go mouldy sooner.

I have jars of jam that I made in 2012 that are still ok, in fact I have one that I am waiting until October to ope on its 10 year anniversary.

The plastic lidded jar was a coffee jar and is now eaten. I'll treat the rest as short shelf life and keep in the fridge.
I've learned from this and will make some more jam when my strawberries and blackcurrants are ready.

OP here, name changed.