800gms tinned peaches (in juice not syrup); tip away juice from one tin;
Chop up the peaches and place them in a large (non aluminium) jam pan, with 1 tablespoon of lemon juice and the liquid from the other 2 tins, and cook slowly in the liquid until soft. Use a potato masher to mash about half of the peaches, so that some of the pieces are larger and some smaller.
Off the heat, add 1Kg of granulated sugar and a knob of butter and stir till dissolved, then add 1 sachet of silver spoon pectin with sugar and stir well until it is completely dissolved throughout the pan.
Bring to a vigourous boil, stirring for 4 minutes and NO LONGER!