Grind the rye for the pre-dough. Mix with the sourdough and water. Cover and let rise in a warm place for about 8-10 hours.
Then finely grind the wheat for the main dough. Toast the sunflower seeds in a pan without fat. Dissolve the yeast in a little lukewarm water. Add the wheat flour and the yeast water to the starter dough. Knead vigorously. Finally, work in 100 g of sunflower seeds. Let go for another 60 minutes.
Add the salt and knead the dough thoroughly again. Now remove 100 g of the dough and keep it for the next bread. Pour the dough into a greased loaf pan and moisten the surface with water. Sprinkle with the remaining sunflower seeds. Let rise for another 20 minutes.
Preheat the oven to 220 ° C and add a bowl of hot water. Slide the bread on the middle rack and bake for approx. 70-80 minutes.