Rinse the apples, you can peel them if desired, cut into slices, fill with water and put in a boil. Cook apples until soft, the time will depend on the variety.
Remove apples from the heat and beat in mashed potatoes with a hand blender.
Add sugar and simmer for 40 minutes, removing the foam.
The jam should thicken, then turn off the heat, put it in sterile jars and roll it up.
Turn the jars of jam upside down and cover with a blanket until completely cooled.