Heat first 6 ingredients until belt melts. Cool and reserve.
Dissolve yeast in water and let stand for 5 minutes until bubbles form. Add to buttermilk mixture.
Add zest, rye flakes or wheat germ and rye flour. Beat until smooth.
Add 3 to 31/2 cups wheat flour, stirring in 1 cup at a time, until the dough will not accept any more. The dough will appear very rough.
Flour work surface with remaining flour and turn out dough. Cover with damp kitchen towel and let rest 15 minutes.
Gently knead the dough, as gluten in rye is more fragile than wheat, until smooth, approximately 5 to 10 minutes. Form into a ball and place in greased bowl, turning to coat all sides. Cover with clean kitchen cloth and let rise in a warm spot until doubled in size.
Punch down dough and gently knead for a minute. Form dough into 3 round loaves and place on lightly buttered baking sheet. Cover and let double in size.
Pre-heat oven to 375°F Combine molasses and water. Brush tops of dough with half of mixture. Pierce the loaves all over the top, gently, with a fork.
Bake for 35-45 minutes, until bread sounds hollow when tapped on bottom. While bread is hot, glaze with remaining molasses and water mixture. Cool on racks.