For the sourdough, mix water, roe flour and rye sourdough and let ripen for about a day.
For the main dough, mix the remaining ingredients and the sourdough and knead for about 5 minutes until a slightly sticky dough is formed. Let the dough rest for about 30 minutes.
Depending on which baking pan you use, shape the dough accordingly, flour / fold it lightly and finally place it in the proofing basket. Let rise for about 70 minutes.
Preheat the oven with the baking stone / baking tray on the highest setting (at least 250 ° C top / bottom heat).
Turn the loaf out of the basket on a floured baking stone / baking sheet and cut into it. Slide in the oven and steam with a bowl of water in a corner of the oven or with a flower water sprayer. After 10 minutes, open the oven door wide to let off the steam.
Then lower the temperature to 200 ° C and bake for a total of one hour. For a nice crust, I recommend leaving the oven door a little open for the last 5 minutes.