Start by bringing water, salt and potatoes to a boil in a large soup pot. Cook the potatoes until you can easily poke a fork through them.
Once your potatoes are cooked, add in the ham, sauerkraut, chopped onion, garlic, dill and caraway. Bring back to a boil and then reduce to medium heat and cover. Simmer for 20 minutes.
While the soup is simmering; in a medium bowl combine the sour cream and flour mixing thoroughly.
Next take 1 cup of the hot soup and slowly stir it into the bowl with the sour cream mixture. Stir until it is blended well. Do this one more time giving you 2 cups of the hot soup/sour cream/flour mixture.
Pour the mixture into the SauerKraut Soup. DO NOT BOIL.