Dissolve the yeast in the warm stock. Stir in the starter, salt, yogurt, eggs, wheat bran, wheat germ, soy grits, and rye flour. Blend this mixture until it is smooth.
Add the whole wheat flour gradually, using enough to make the dough easy to knead. Knead until smooth and elastic, then let rise until double.
Punch down, shape into loaves (you may make 3 large loaves instead of 4 small), let rise again in oiled pans.
Bake the loaves at 375°F for 40 to 45 minutes.