Start the Detmolder 3-stage process at 6:00 AM on day 1.
For the first stage, mix the sourdough starter, water, and whole rye flour and let it sit for 6 hours.
For the second stage, use the mixture from the first stage and add more water and whole rye flour, letting it sit for 24 hours.
For the third stage, again use the mixture from the second stage and add more whole rye flour, letting it sit for 5 hours.
After the third stage, mix all the ingredients for the final dough and knead for 5 minutes.
Let the dough rest for 5 minutes, then knead for another 5 minutes until smooth.
Form the dough into rough loaf shapes and let it rest covered for 30 minutes.
Shape the loaves and let them rise until almost doubled in size, about 2 hours.
Preheat the oven to 450F and bake the bread for 10 minutes, then lower the temperature to 350F and bake for another 45 minutes.