To set well, jam needs the right balance of pectin and acid. Lemons provide the acid, but different types of fruit have various levels of pectin.
Pectin rich fruits include apples, gooseberries, blackcurrants, redcurrants and damsons. Combine fruits with differing pectin contents, such as strawberries (low in pectin) and redcurrants, or apples and blackberries (also low).
Test the jam for setting point when it reaches 105°C/220°F (use a sugar thermometer to test the temperature). Dip a wooden spoon into the jam, lift it out horizontally and keep it in this position to cool. Then tilt the spoon and let the jam fall off it. If small drops run together on the edge of the spoon to form larger drops that then fall cleanly off the spoon, the jam has boiled long enough.
Or, drop a small spoonful of the hot jam onto a cold plate. If it forms a skin on the surface as it cools, which wrinkles when you press it, the jam is at setting point and is ready to pot.
If the potted jam is runny and won't set, don't reboil it - you will only ruin its flavour. Dissolve gelatine in warm water, warm the jam - simply so that you can mix it with the warm gelatine - and stir it into the gelatine solution. (Use 5-6 teaspoons of gelatine for 2½-31b/1.1-1.4kg of jam.) Pot it again and refrigerate when cool. Use it within a few weeks or it may become mouldy.
This tip has 7 comments shown below
Comments by: Sally from UK Jun 15, 2011
As a relative novice to jam making, it's nice to have simple clear instructions on how to reach setting point
jam setting King!
Comments by: Deedee from Deux Sevres, France. Oct 16, 2010
You've solved a lifelong problem for me. My jam either sets so hard that you can trot a mouse on it or it's a sauce...... that wooden spoon idea is so easy and I'll try it tomorrow. Many thanks.
Great tips, but....
Comments by: Denise from Tasmania Dec 19, 2009
Hello, I'm new at jam making and right now am making gooseberry jam. The recipe said cook to jam setting but didn't really know what that was.
This advice was great, but I couldn't copy and paste it into doc form to be able to print out and refer to..... All that I got with Ctrl C, and Ctrl V, was a double line. Denise (Tasmania)
rescue method if it hasnt set?
Comments by: Sally from Australia Nov 30, 2009
My friend says that you have to boil up some chopped granny smith apples then tie them in muslin and tie to a wooden spoon suspended over a bowl in the fridge so it drains overnight. Then add the apple juice that you have collected back in with the jam and reboil. Has anyone heard of this? How long do you boil it?
TipKIng says:Makes sense they are rich in pectin which is what sets the jam. I would boil them till they are falling apart. Hope this helps
Comments by: michael from GB Oct 24, 2009
i boil for ages & the jam still wont set
Comments by: ANONYMOUS from RHOS ON SEA,COLWYN BAY, WALES,UK Dec 23, 2008
THIS METHOD IS RIDICULOSLY RETARDED AS IT TELLS YOU NO TIMES OF SETTING POINTS AND ONLY SHOWS THE METHOD OF KNOWING!!!
setting rhubarb jam
Comments by: Mo from Glasgow, Scotland Aug 04, 2008
i have always had problems setting rhubarb jam and i always use recipies. Where am i going wrong ? Mo