Place ribs in a large pot, cover them with water and bring to a boil. Reduce heat and simmer for 15 minutes. Drain the water and cool the ribs until you can touch them. Cut them into 1 or 2 rib portions. Sprinkle with salt and pepper and set them aside.
In a large Dutch oven sauté the onion in shortening until glassy. Add the ribs, reduce the heat and cook for 15 minutes, stirring occasionally.
Drain sauerkraut and add it to the ribs. Pour water and wine over the ribs. Add the apple, bay leaf and cloves, turn up the heat and bring to a boil. Turn down heat to low, cover the pot and simmer for 1 1/2 hours.
Peel, wash and grate the potato and place into the sauerkraut mixture. Add a little water if needed. Stir and simmer another 1/2 hour. Season with salt and pepper and a dash of sugar.