Mix rye flour, wheat flour and wheat bran. Crumble the fresh yeast and add the sourdough and mix well in the food processor.

Add the sour cream, salt and caraway seeds and stir.

Now slowly add lukewarm water. As soon as the dough becomes crumbly, stop adding water and let the dough knead for about 10 minutes. It has to come off the edge of the bowl well.

Now shape a loaf and place it on a baking sheet dusted with flour, cut into it and let rise under a bowl for about 1 hour at room temperature.

Preheat the oven to 250 degrees.

Sprinkle the bread with salted water and dust some flour over it.

Reduce the temperature to 220 degrees, put a bowl of cold water in the oven and bake the bread for about 40 minutes.