In a large bowl; Add the cracked rye kernels, cracked wheat, flax seeds, sunflower seeds, water, malt syrup and the sour dough. Let it all soak for minimum 8 hours. This can with advantage be done in the evening, so that you can continue the morning after.
After about 8 hours; add the rest of the ingredients and let the rye bread dough rise for about 1.5 hours.
Divide the dough into two portions and pour it into two normal bread pans. Cover the bread pans with some plastic wrap (or a damp dishtowel). Let the dough rise for about 1-2 hours or until the bread pan is full of dough.
Bake the rye breads at 180 C (360 F) for about 1 hour.
When done; remove the breads for the bread pans and let them cool off. When the breads are cooled off; keep them in an air tight container or a plastic bag.