Dissolve the ready-to-bake wheat sourdough in a bowl in the water. Add the flour and salt and knead briefly. Then add the hazelnuts and knead everything well. Cover the dough in a well-floured bowl and let rise for 1 1/2 to 2 hours. Then place on the floured work surface and leave to rest for about 5 minutes, covered with a kitchen towel (you can of course also make bread rolls from the dough, then divide it into 6 - 8 pieces and then let it rest for 5 minutes).
After the short rest, form a loaf of bread (or roll) and let rise on a baking sheet for about 1 1/2 hours. Preheat the oven to 50 ° C 10 minutes before the end of the walking time. Then put the tray with the bread in the oven.
After 1/2 hour, cut the bread crosswise with a sharp blade and set the oven to 200 ° C. After 1/2 hour reduce the temperature to 180 ° and bake the bread in about 20 minutes.
If the bread sounds hollow when you tap the underside, it`s done!