Mashed Potatoes with lemon

2 cups water, divided 1 teaspoon brown sugar 1 small lemon, halved and juiced, halves reserved 1 large apple (such as Honey Crisp), peeled and chopped 4 large[...]

2 1/2 lbs baking potatoes , such as Yukon Gold, peeled and cut into 2 inch cubes 1/4 teaspoon salt 1/2 cup skim milk 2 tablespoons butter or 2 tablespoons[...]