Kyselo (Czech Sourdough Mushroom Soup)

• Potatoes
• 100 g sourdough starter, ideally made with rye flour
• 15 g dried porcini mushrooms, preferably Central European
• 1 tablespoon caraway seeds
• 1250 ml water
• 1 onion, chopped
• 20 g butter
• 3 chicken eggs
• Salt
• Vinegar
• Chopped green herbs, such as parsley or scallion

Ingredients for 5 servings (2.2 kg) · the original recipeShow how each ingredient was counted

Method

1. 1

   Boil potatoes with their skins, then peel them, chop onto small pieces and roast it in a pan (without adding grease).

2. 2

   Put 250 ml tepid water into a bowl. Stir in the sourdough starter. Cover with a clean cloth, and let rest at room temperature for 30 minutes to 3 hours.

3. 3

   Put 1000 ml water into a stockpot. Add the dried mushrooms and caraway, and boil for at least 15 minutes to make a strong broth.

   Stovetop
4. 4

   Carefully add the sourdough mixture into the broth, stirring well—there is a danger that the sourdough will shrink into small dumplings.

5. 5

   Boil the soup, stirring, until the sourdough thickens the mixture. This should take about 10 minutes.

   Stovetop
6. 6

   Sauté the chopped onion with butter in a pan. Stir it into the soup.

7. 7

   Beat the eggs with a pinch of salt, and scramble them in an ungreased pan. Stir the cooked eggs into the soup.

8. 8

   Season the soup to taste with salt and vinegar. It should be mildly sour, flavored primarily by the mushrooms and sourdough.

9. 9

   Served the soup hot, garnished with the chopped herbs, with the potatoes as a side dish. Individual diners may wish to add additional vinegar and salt to taste.