1500 g  Flour, rye

    750 g  Sourdough

    900 ml Water, 30C8C/ 85C8F

      1 tb Salt

    150 g  Molasses

  Mix sourdough with a part of the flour and let rest for 5 min. Add water
  and the rest of the flour and knead well. Cover and let rest for 2 1/2 - 3
  hours at a warm place. Add salt and molasses and kned well. Part in two
  halfes and give in oven-forms. Bake for 12 hours at 100 C8C/ 212 C8F. Let
  cool down for one day before cutting.
  "Wie man eyn teutsches Mannsbild bey Kraefften haelt." (Historic recipes)