Cut unpeeled apples into slices, removing bruised or diseased portions. Stew apples till soft in just sufficient water to prevent burning. Rub through a sieve. Add a paring of lemon rind and sugar to taste. Immediately return the pulp and rind to the pan, bring to the boil, stirring to dissolve the sugar, pour into hot preserving jars and seal at once. Process as for pulp above.