Make a sourdough from the first three ingredients and let it stand for approx. 16 hours at room temperature.
Then remove 50 g of the sourdough and put it in a jam jar in the refrigerator as a topping.
Knead the remaining ingredients with the food processor on the lowest setting. Let the dough rest for about 30 minutes. Then act the dough. The dough is a bit sticky, but it is still easy to work with. Then let rise in a proofing basket. (Do a finger test in between.) This can take approx. 60 minutes with the addition of yeast, without approx. 120 - 240 minutes.
Preheat the oven to 250 ° C.
Bake: The first 15 minutes at 250 ° C, on the middle rail. Spray into the oven a few times with the flower sprayer. Then bake the bread for 20 minutes at 200 ° C and then for another 20 minutes at 180 ° C.