Prepare the fruit. Wash the apples and orange. Cut the apples into large chunks and slice the orange. There is no need to peel the apples.
Fill the slow cooker. Add the apples, orange slices, cloves, cinnamon sticks, brown sugar and allspice to the slow cooker. Pour in 8 cups of water.
Cook for 4 hours. Cover and cook on HIGH for 4 hours, or until the apples are very soft.
Mash the apples. Use a potato masher to thoroughly mash the softened apples directly in the slow cooker.
Strain the cider. Pour the mixture through a fine mesh strainer into a large bowl or stockpot. Gently press the apples to extract as much cider as possible. For clearer cider, strain it a second time through cheesecloth.
Sweeten. While the cider is still hot add more brown sugar if desired.
Serve or preserve. Serve the cider warm, refrigerate it for later, or continue with the water bath canning instructions.