First cake: weigh the water, sprinkle with a little yeast (some recipes give 0.1 g, but who can weigh that?). Add the flour and stir well. Leave in the warm for an hour and then in the refrigerator for 24 hours.
Sourdough: I have my own in the fridge that needs to be fed regularly. There are some to buy or there are enough instructions available on how to do it, so that I save this description here.
Main dough: Weigh the water, add the yeast. Weigh the flour, sourdough and the other ingredients and add except for the creme fraiche. Add the pre-dough and let the food processor mix for 5 minutes on the lowest setting. If the dough is still too dry, a little water can now be added. Now add the creme fraiche. Those who like it more rustic (and actually it's a pané rustico) use lard instead. Then knead for 10 minutes on the next higher level. The dough is now slightly sticky, but it comes off the bowl well. The ideal dough temperature would be 22 - 24 ° C.
Take the dough out and place it on a lightly floured surface and leave to ferment there covered for 2.5 hours. Stretch and fold again every 30 minutes. After this time the dough has increased in volume and is now left to mature for 24 hours in a sufficiently large container with a lid in the refrigerator.
The next day, preheat the oven to 250 ° C. (Mine unfortunately only brings 225 ° C, as a disadvantage of the combi steamer). If a baking stone or pizza stone is used, please preheat for 45 minutes.
Take the dough out of the refrigerator and let it sit for a while to acclimate. Shape the dough into three strands on a lightly floured surface, roll them in the wheat meal and twist the ends of the individual strands against each other. Let rest for 30 minutes. When the parts are in the oven, reduce the heat to 230 ° C and bake with plenty of steam for 18-20 minutes.