Vegetarian Sauerkraut Soup

Why sauerkraut works in soup

Sauerkraut soup is a cold-weather staple in several Central and Eastern European kitchens, where it is often made with smoked meat or sausage. A vegetarian version can be just as satisfying if you build depth another way: browned onion, tomato paste, smoked paprika, potatoes, and beans. The sauerkraut supplies tang, which balances the starchy vegetables and richness.

If you already have a jar of homemade or store-bought kraut, this is an easy use for it. For a related side dish, see our sauerkraut kapusta recipe.

Ingredients

For about 6 servings:

• 2 tablespoons olive oil or butter
• 1 large yellow onion, diced
• 2 carrots, diced
• 2 celery stalks, diced
• 3 cloves garlic, minced
• 1 tablespoon tomato paste
• 1 to 2 teaspoons smoked paprika (sweet paprika also works)
• 1 teaspoon caraway seeds (optional but traditional in many sauerkraut dishes)
• 2 bay leaves
• 1 pound potatoes, peeled and cut into bite-size cubes
• 6 cups vegetable broth, or water plus a good bouillon
• 1 1/2 to 2 cups sauerkraut, drained, plus a few tablespoons of its brine
• 1 can (15 ounces) white beans or chickpeas, drained and rinsed
• 1 to 2 teaspoons sugar or maple syrup, to taste
• Black pepper
• Fresh dill or parsley, and sour cream or a plant-based alternative, for serving

Step by step

1. Soften the base. Heat the oil in a large pot over medium heat. Add the onion, carrots, and celery and cook until soft and lightly golden, about 8 to 10 minutes.
2. Add flavor. Stir in the garlic, tomato paste, paprika, and caraway. Cook for a minute or two until fragrant.
3. Add liquid and potatoes. Pour in the broth, add the bay leaves and potatoes, and bring to a simmer. Cook gently until the potatoes are nearly tender, about 15 minutes.
4. Add the kraut and beans. Stir in the sauerkraut and beans. Simmer another 15 to 20 minutes so the flavors blend.
5. Taste and adjust. Add a pinch of sugar if the soup is too sharp, a splash of brine if it needs more tang, and pepper. Hold off on adding salt until the end, since sauerkraut and broth are often already salty.
6. Rest and serve. If you have time, let the soup sit for 30 minutes off the heat. Remove the bay leaves, then serve with dill and a spoonful of sour cream.

Adjusting tang, salt, and body

• Too sour: Rinse the kraut next time, add a little sugar, or add more potatoes and broth. Epicurious’s sweet-and-sauerkraut soup uses apples and small amounts of sugar for this reason.
• Not sour enough: Add more kraut or a few spoonfuls of brine at the end.
• Too salty: Dilute with unsalted water or broth and extra potato. Avoid adding more salt, and use low-sodium broth next time.
• Too thin: Mash some of the potatoes or beans against the side of the pot.
• Too flat: Smoked paprika, a little tomato paste, and a splash of soy sauce or nutritional yeast can add savory depth without meat.

Variations

• Mushroom: Brown sliced mushrooms with the onions for deeper flavor. Dried mushrooms soaked in hot water, with the strained soaking liquid added to the pot, are popular in many Eastern European sauerkraut soups; see dried black trumpet mushroom recipes for how to dry and rehydrate them.
• Apple: Add a diced apple with the potatoes for a sweet-and-sour balance.
• Bean: White beans, chickpeas, or kidney beans all work.
• Smoky tempeh or plant-based sausage: Brown diced tempeh or sliced sausage separately and add to each bowl.
• Greens: Stir in spinach or kale at the end.

Common mistakes with vegetable soup

• Skipping the browning step. Letting the vegetables soften and pick up color builds flavor.
• Overcooking the potatoes. Cube them evenly and watch the clock so they hold their shape.
• Salting too early. Taste at the end after the kraut has had time to season the pot.
• Adding too much kraut at once. You can always add more.
• Boiling hard. A gentle simmer keeps vegetables intact and the broth clear.

What do Germans add to sauerkraut?

Practices vary by region and family. Common add-ins to cooked sauerkraut in German-style cooking include onion, apple, caraway seeds, juniper berries, bay leaves, potatoes, and sometimes a little sugar or white wine. In a vegetarian soup, caraway, bay, apple, and potato are the easiest to borrow.

A note on live cultures

Cooking sauerkraut heats and likely kills the live cultures in it. The soup is a way to enjoy its flavor, not a source of live bacteria. If you want to keep some raw kraut, stir a spoonful into individual bowls after the soup has cooled slightly, or serve raw kraut on the side.

Storing and reheating

Refrigerate leftovers within two hours of cooking in shallow containers. USDA guidance generally suggests eating refrigerated leftovers within 3 to 4 days. The soup also freezes well, though potatoes can become a little soft or grainy after thawing. Reheat until steaming hot throughout. The flavor often improves on the second day.

Looking to make your own kraut? Start with our guide to fermented foods that taste good for ideas, or see how to lacto-ferment peppers for another salt-brine project.