Wash, roughly core, and cut up the apples. Place in a large kettle and add enough water or cider to come about ⅓ of the way up the apples. Cook until the apples are well done and easily break up. Strain the apples, measure, and return to the kettle.
Note: One way to speed up the final cooking of the jam is to cook part of the apples, covered, in the microwave