1. In a large bowl, dissolve yeast in warm water. Add buttermilk, butter, honey, salt, baking soda, wheat germ and 4 cups flour. Beat until smooth. Gradually stir in enough remaining flour to make a soft dough.
2. Turn onto a heavily floured surface; knead until smooth and elastic, about 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and let rise in a warm place until doubled, about 1 hour.
3. Punch dough down. Turn onto a floured surface; divide into thirds. Divide each portion into thirds; shape each into a 12-in. rope. Braid three ropes; pinch ends to seal and tuck under. Place in a greased 9x5-in. loaf pan. Repeat with remaining dough. Cover and let rise until doubled, about 45 minutes.
4. Preheat oven to 350°. Bake 40-45 minutes or until golden brown. Remove from pans to wire racks to cool. Yield: 3 loaves (12 slices each).