The Cottage Smallholder

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What is the setting point for jam and jelly?

Jam thermometer and maslin pan for jam making

Maslin pan with thermometer on our busy hob

Earlier this summer I decided to use my jam thermometer to help me find the setting point of jam. To my delight I noticed that it was marked ‘JAM’ at 105°c/220°f.
“This is going to be so easy.” I thought. “No more trailing back and forth to the fridge waiting for a tardy batch to set.”

Danny had bought me a 9 litre Maslin pan and this was the day it was christened. Up until then I had been using a very large non stick saucepan. So I clipped the thermometer to the side of the pan and feeling like a pro started to boil the jam.

I waited and waited, watching the jam get thicker and more gloopy. All the signs indicated that the jam was setting – coating the spoon, a thick residue on the sides of the pan but I persisted – determined to believe that a temperature of  105°c would produce perfect and tasty jam. I did eventually lose a bit of faith in the thermometer. Perhaps the jam was hotter in the centre of the pan? I moved the thermometer about but the temperature remained the same.

When the jam eventually reached the magic JAM level I took the pan off the stove. I didn’t need to test for a set – it was like glue and all the fresh fruity taste had gone. In fact the jam stuck so hard to the thermometer that it rubbed off of most the markings for the lower temperatures.

I did a bit of research on the Internet and discovered that 105°c is generally seen to be the setting point for jam. What had gone wrong? I checked the reviews for the Tala jam thermometer but no mention was made of  temperature faults. The reviewers did point out that the temperature points on the thermometer could easily be wiped away. Next time I’ll invest in a thermometer with etched points. The jam went down the loo and took a few days to shift. Danny was a bit irritated.

So much so that I wanted to chuck the thermometer over the fence but luckily kept it as I’ve discovered that our jam thermometer is useful as an indication that a jam/jelly is nearing setting point. When the temperature reaches 102°c, I stop whatever I’m doing and hover by the pan testing for set every five minutes on a plate from the freezer. The set happens somewhere between 102°c – 103°c, usually after ten minutes or so. I’d love to hear the temperatures that you use to gauge the setting point for jam.

By the way I thoroughly recommend investing in a Maslin pan if you are keen on making preserves. Apart from the thermometer fiasco all my jams, jellies and chutneys have been much easier to make this year. Perhaps is just that the design of the pan – a larger surface area compared to the base. Even the “glue 105°c jam” didn’t burn the base. This combined with a Silicone Spatula means that not a drop of jam is wasted and washed away in the sink.

Up until now I thought that Maslin pans were an unnecessary expense. Like my attitude to the simple but efficient jam funnel I have been proved wrong, yet again. The latter is used constantly for putting rice/beans/lentils/whatever into jars. And when I make preserves so little is wasted that it paid for itself in no time. And now I wouldn’t give up my Maslin pan without a strenuous, elongated fight.

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  1. I forgot to add that your jam recipe must be correct. It won’t set if you cut down the sugar and it certainly won’t keep, also you must have the correct amount of water.
    I have a kitchen craft thermometer which I think I got from Lakeland. I wouldn’t be without it

  2. Well, I’ve just made some lovely plum jelly.
    I always use jam sugar( it has pectin) whatever the fruit and in this , I also put in some lemon juice.
    I boiled it at a Rolling Boil- I think this is essential, the temp was 102* and I boiled it for 10 minutes
    The first test was successful- a pudding spoon , in the freezer, dip in pan and put back in freezer. It was set nicely after it was cooled.
    I think he eproblem some have is that you can go past the setting point and then your jam or jelly will never set- just be gooey with no flavour
    So Don’t Overboil!
    I hope this is helpful

  3. how long does it need to boil once it reaches setting point?

    • Erna Rae

      Once it reaches setting point you can STOP boiling the jam. Or to put it another way, you boil the jam until it reaches setting point.

  4. Busygreenmum

    No matter how long I boil the jam my jam thermometer never ever rises above 100 degrees c so I have resorted to the saucer test and what looks about right – and seems to turn out OK despite the thermometer. Mines a Kilner one – and very difficult to use. Won’t clip onto the Kilner jam pan without falling in.

  5. Elderberry and Blackberry Jelly at 105 did set but moved around the jar in one solid mass. I questioned myself , did I try to make too much. were the jars too hot, I poured into the jars from my Maslin pan. I am now trying to add another half pint of apple juice plus half pound of sugar and mixing all as if starting from scratch.

  6. nancy elena

    Just finished making QUINCY JELLY, (still hoping that it will be OK)

    Recipe said 25 minutes plus…used the thermometer, also dish/freezer wrinkle testing…) in all it took about 40 minutes…lots of glue on the pot…but never quite wrinkle…half of my mixture evaporated as well…Do not know what i did wrong?
    Nowhere said that the thermometer actually helps to make JAMS OR JELLYS… a bit frustrated righ now.

  7. For all those people having trouble with jam thermometers, can I recommend the digital thermometer embedded in a silicone stirring spoon available at Lakeland shops. It is brilliant, and very useful for testing things other than jam as the thermometer rod can be removed from the silicone spoon. I bought it for jam making and it hasn’t let me down. I find my jam setting between 103C and 104C.

  8. Your pan size needs to be matched to your jelly volume for your thermometer to work. Thermometers are only accurate when immersed to a certain point.. Shallow is no good.

    • Crazyfox

      Ahh. Now that seems like good information. I have made marmalade with a thermometer and it worked, just great. But, today a made a small amount of jam, but I couldn’t get the heat up and eventually it burnt!! So, I would suggest immersing a digital thermometer at least half way up the shaft.

  9. Deb S

    As I understand it, jellies and jam set at lower temperatures if you’re at an altitude above sea level. Here’s more information:

  10. Andrew Charles

    Maslin in this context is an old word for a type of brass (Old English maeslen), the type used for making kettles or cauldrons. It came to refer to any kind of vessel made from maslin brass, and later to this specific type of kettle for making jam. Although brass jam kettles can still be found in antique stores few people realized that the name referred to the material, and not the form, and so it came to be used for jam kettles of any material as they became available. It is also known as a mashing kettle, but it is believed this is a case of folk etymology (people trying to make sense of a word whose true meaning is forgotten), in the belief that it was first used to making home-made beer.

    Maslin can also refer to mixed grains or other materials, but this word is more recent (borrowed from the French in the 14th century) and unrelated to the brass or kettle.

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