In stockpot, combine water, potatoes and salt. Heat to boiling. Cook until potatoes are almost tender, about 15 minutes.
While potatoes are cooking. Heat a medium fry pan over medium high heat. Add 1 Tablespoon neutral oil, such as canola. Once the oil is shimmering, add the chopped onion. Lower heat to medium and cook onions, stirring often, for about 7 min. Or until starting to soften. Add garlic and cook until fragrant. About 1 minute. Remove from heat.
Using a 1 cup measuring cup, fish out 1 cup of the starchy water. Add the sour cream to the water and whisk until smooth. Set aside
Without draining the water from the potatoes, add sausage, sauerkraut, dill and caraway. Simmer for 5 - 10 minutes or until everything is heated through.
Just before serving, stir the sour cream mixture into the soup.
Heat thoroughly over low heat. Serve immediately.
Notes
Tips
Purchase pre-cooked links of your favorite smoked sausage. Bratwurst is a natural choice, Kielbasa works good and I've even used Andouille for a spicier soup.
If you purchase Bavarian style sauerkraut, it will already contain caraway seeds. You may want to skip adding additional caraway seeds. Or perhaps half of what is called for in this recipe.