For this jam I used
1.1 kg of raspberries (as this is what I had)
1.1kg of sugar
juice of half a lemon
The basic ruling is equal quantity of sugar to fruit. Use around half a lemon for each kilo of fruit you use.
Heat the fruit in a large pan. The bigger the better, even if you are thinking that it looks daft, trust me jam is a messy business.
Heat until the juices start flowing from the fruit. This takes around 5 minutes for raspberries.
You don't want the mixture to boil so keep the heat medium.
Remove from the heat and stir in the lemon juice.
Stir in the sugar and place the pot back onto the heat. Make sure it is low. Stir the mixture gently but continuously until the sugar has completely dissolved.
Turn up the heat and bring the mixture to the boil. Cook at boiling for 4 minutes. If foam appears either add a knob of butter to disperse it or scoop it out - I am a scooper!
After the four minutes check for setting. If you have a jam thermometre this makes life easier if you don't then follow my guide below for the saucer test.
Using sterilized bottles or jars fill to the top and put the lid on while the jam is still hot. Allow to cool.
Label your jam. This jam should keep for around 9 months if unopened.
*The saucer test: place a saucer into the freezer for about 5 minutes. When ready for the test, remove from the freezer. Drop a spoonful of the jam onto the saucer. Leave for about 5 minutes. Run your finger through the mixture, if it wrinkles then the jam is ready.