In a large bowl combine 3 cups hot water, the sugar, salt, oil or butter and the dry milk powder; stir well and allow to cool to lukewarm. In a small bowl combine 1/2 cup warm water (100° to 115°) and the yeast, let stand for 5 minutes to dissolve. Add the dissolved yeast and 2 cups of the whole wheat flour to the first mixture. Stir well. Cover and let stand 10 minutes (or longer if you wish.) Add remaining whole wheat flour. Then add 2 cups bread flour, oat flakes, bran, cornmeal, bulgur wheat and semolina, if used. Mix well. Turn out onto a floured board and knead for a minute or two. Then cover with a bowl and let rest 10 minutes. Adding just enough of the remaining flour so that the dough is not sticky, resume kneading until the dough is elastic, 8 to 10 minutes. Place dough in a large greased bowl; cover and let rise in a warm place until doubled in bulk. Punch dough down and shape in 3 loaves. Place in 3 greased loaf pans. Cover and let rise until just double again. (Do not let dough get too light or it may fall when transferred to the oven.) Bake at 375° 40 to 45 minutes. Remove from pans and cool on racks.