Combine all of the ingredients in a slow cooker set to high. Once an hour stir the apple butter scraping down all the sides and bottom of the slow cooker. Repeat this process for 4-5 hours or until the mixture is very thick and dark. To tell when the apple butter is done, drop a small spoonful of it on a plate and wait a minute or two. When the apple butter is done, a liquid ring will no longer ooze to the outside of the drop of apple butter; it will stay solid. Store in the refrigerator. Or, to can, carefully pour into in sterilized jars and process for ten minutes in a hot water bath.