LeBonn's Russian Cabbage Soup

Core and thinly slice cabbage (can use food processor fit with thinnest blade). Drain sauerkraut, discard pickling liquid, rinse well under cold running water, and squeeze dry. Melt butter in 3-quart Dutch oven over medium-low heat. Add cabbage or sauerkraut and cook, stirring occasionally, over medium heat until it begins to wilt (about 10 minutes). Add all remaining ingredients except sour cream. Raise heat to high and bring to a boil. Reduce heat to medium, cover partially, and simmer until cabbage is tender (about 30 minutes). Taste to adjust seasoning, adding a bit more sugar or lemon juice if desired. When ready to serve, ladles into warmed soup bowls, and spoon a rounded tablespoon of sour cream in the centers.