Put both types of flour in a bowl. Sprinkle salt and bread spices on top. Dissolve the yeast in warm water and add to the flour with the sourdough.
Knead everything into a smooth dough, then let it rest for 2 hours. Knead the dough again and place on a baking sheet lined with baking paper, cover and let rise for another 30 minutes.
Preheat the oven to 220 ° and bake for about 10 minutes. Switch back to 200 ° and bake the bread in about 35-45 minutes.