Find out how to test a jam for set, pot and seal you preserves with these hints and tips?
Do you know when your jam has reached setting point? Or how to sterlise jars? What is the best way to pot and seal your jar. Follow these tips to ensure your jam preserving is sucessful
How to Test for Set
When making jams and preserves you will need to test to see if setting point has been reached. Some recipes will give you a temperature but this can still vary, so it is worth testing as well.
- Before you start making your jam or preserve, place a couple of plates in the fridge to chill.
- When you are ready to test for set, drop a little of the preserve onto a chilled plate and return to the fridge for about 2 minutes. Gently push your finger into the mixture and see if it mounds and wrinkles. If so, the setting point has been reached.
- If not, return the mixture to the boil for another 5 minutes and retest. Repeat again as necessary until setting point is reached.
Remember to turn the preserve off while you test for set.
How to sterilise Jars
- Wash the jars in warm soapy water and rinse well. Do not dry.
- Place the wet jars on a tray, heat the oven to 140℃ (120℃ fan)/275°F /gas 1 and put the jars in the oven to dry completely.
- Sterilise the lids (and rubber rings if using Kilner style jars) in a pan of boiling water for 5 minutes.
I always sterilise one or two more jars than I think I will need, to ensure I have enough.
Filling The Jars
- Fill the jars while they are still hot.
- Jellies and shredless marmalade can be potted immediately after setting point has been reached.
- Jams with fruit pieces and marmalades with shreds should be allowed to cool slightly and stirred. This will evenly distribute the pieces and prevent them from rising to the top of the jar.
- Use a wide funnel to make filling easier.
- Fill almost to the rim to allow for shrinkage on cooling.
- Pack chutneys and thicker preserves down well and try to exclude any air bubbles.
Sealing
- Immediately each jar is filled, cover the top with a waxed disc (wax side down) or piece of parchment so that it lies flat on the surface and excludes any air. This will help to prevent mould forming in storage.
- Then place the lid on the jar while the jam is still hot.
- Jars can be sealed with cellophane secured over the jar with a rubber band. As the preserve cools the cellophane will tighten producing and airtight seal.
Storing
Remember to label and date your preserves before storing. Store in a cool dry place. Most preserves will keep for several years if stored well. Refrigerate after opening and use within a few months.
Do I need to use a water bath?
In some countries preserves, jams and jellies are further processed in a water bath. Traditional UK jams tend to have a higher sugar content so this additional step is not required. If the jam has reached setting point and the jars are sterilised and sealed properly the jam will still keep safely for up to 1 year.
If a preserve required this additional step the recipe should give instructions on how to carry out this process.
Carolyn says
Hi jacqui I’ve a lot of gooseberries from last year in my freezer. If I make them into jam do I use the same amount of water as stated in your recipe or do I need to reduce it? Thank you Carolyn
Jacqueline Bellefontaine says
Hi Carolyn Yes just use the same amount of water and follow the recipe as it is. Frozen gooseberries work very well.
KAREN GREEN says
HI, Do you turn the jars upside down to cool overnight after filling the sterilised jars with the hot jam?
Jacqueline Bellefontaine says
Hi Karen, Noi I never turn my jars upside down after filling with the hot jam. I've never understood the logic for this. Fill the jars almost to the prim and place a disc of waxed paper on the top. Then fit the lid. As the jam cools a vacuum is formed and there is very little air left in the jar. Using this method I have found almost all the jams I have ever made will keep for at least a year.
Abbey says
Hi, I am making some jam for gifts and have just normal jam jars for example the ones that you would get your supermarket jam in. How would I seal these best? Also how long will the keep for? Many thanks!
Jacqueline Bellefontaine says
Place a disc of wax paper on top then seal the jars while they are still hot. As the jam cools it will form a vacuum.
Liz Haskew says
Hi!
I'm making green tomato chutney for the first time! Can I re-use jars and lids which I've saved? I've read that even if I sterilise these (jars in oven & boil lids) this isn't enough to prevent harmful bacteria from making the chutney unsafe. I'm confused & would appreciate some clarity!
Thank you,
Liz
Jacqueline Bellefontaine says
While Im not an expert in microbiology I have not heard this before. (Where did you hear this?) I have been reusing jarsfor preserves all my life and indeed every one I know who makes them also reuses jars. I do of course make sure i sterlisie them before use and I do avoid jars that have hard strong smelling foods such as pickles as these can retain odours that taint the flavour of the new preserve (usually in the rubbery sealing ring). Avoid usig jars where the lids have started to corrode too.
Sophie Buckman says
Hi - I am making some jam and chutneys about three months ahead but want to know if I need to buy "preserving jars" with the pop down lids; or will I be ok using jars that do not have the pop down lid?
Thank you!
Jacqueline Bellefontaine says
Sorry Sophie I don't know what you mean by pop down lids. You can use pretty much any glass jars with lids for jams and preserves so long as you sterilise them first. Avoid using jars that have had strong smelling foods in them like pickles especially for jams as they smell may linger and taint the flavour of the new preserve over time.
Amy says
Hi, I’m using Kilner jars with the attached flip top lid, would I sterilise these in the same way? And when creating an airtight seal, is that the same process as well?
Thanks in advance
Jacqueline Bellefontaine says
Hi Amy
Yes you would sterilise the jars themselves in the same way, however remove the rubber seal first as these will perish with the dry heat. Sterilise the rings in a pan of boiling water for a few minutes before removing from the hot water and popping back in place on the warm jars. To make the airtight seal fill the jars almost to the rim. Place on a disc of wax paper then close the jars while still hot. This will cause a vacuum as the preserve cools giving a good airtight seal. Hope this helps and if you have any other questions just ask. Enjoy your preserves.