2 pounds underripe Granny Smith apples, washed and cut into eighths (not peeled or cored)
4 cups water
In a large saucepan, over high heat, bring the apples and water to a boil. Reduce the heat to medium and simmer for 20 minutes or until tender. Remove from the heat and cool. Line a large bowl with dampened cheesecloth. Pour the pulp and juice through the cheesecloth. Gather the corners of the cheesecloth, and tie in a knot. Suspend from a cabinet knob or handle and allow to drip into a bowl overnight. The next day, measure the apple juice and pour into a large pot. Bring the liquid to a boil over high heat and cook until reduced by half. Refrigerate and use within 4 days or pour into containers and freeze for up to 6 months.
Recipe from Preserving the Taste by Edon Waycott (Hearst Books)