We have a glut of fruit at the moment, and although I am fast running out of jars now, this is the way I make my sweet pie fillings to keep for winter.
All I do is , wash and clean the fruit, at the moment its black berries or peaches.
The blackberries are put in the preserving pan, any large heavy pan will do, with just a small amount of water, to one kilo of fruit I add around 200 ml of liquid.. gently warm the fruit till the juice runs... simmer away till fruit is soft and fallen. Add equal amounts of sugar to fruit... bring to a rolling boil as in making jam... but dont expect it to thicken like jam.
For the peaches I just peel, and pit them, cut into chunks as it will cook down to a pulp. (half the water though) I also add the odd clove and a handful of dried fruit... and cook as for the berries, when all has fallen to a soft pulp, add the sugar, and rolling boil..
Meanwhile, scrub jars well, I then fill my washing up bowl with boiling water, slip in the jars and lids, and leave to sterilise for a few minutes, then with tongs I pick one at a time out, fill with red hot fruit , and put a paper circle on inside to seal against the air, then screw on lids tight. Mine always keeps for all winter...
Perfect for a quick pie filling, fruit turnovers, or just on pancakes ... yummy...