Combine first 5 ingredients in a Dutch oven; bring to a boil. Reduce heat, and simmer, uncovered, 30 minutes or until lentils are tender.
Cook bacon in a nonstick skillet over medium heat until crisp. Remove bacon from pan; crumble. Reserve 1 tablespoon drippings; discard remaining drippings. Combine bacon and sauerkraut in pan; cook 1 minute or until thoroughly heated.
Add reserved drippings, salt, and pepper to lentil mixture. Spoon soup into individual bowls; top with sauerkraut mixture.