Nutrition per serving may change if servings are adjusted.
2 1/2 cups nonfat milk
1/2 cup dark brown sugar
1 1/2 tablespoons active dry yeast, (two 1/4-ounce packages)
3 cups whole-wheat flour
2 1/2-3 1/2 cups unbleached bread flour, divided
1/2 cup cracked wheat
1 1/2 tablespoons oat bran
1 1/2 tablespoons unprocessed wheat bran
1 1/2 teaspoons salt
Combine milk and brown sugar in a small saucepan; heat over medium heat, stirring to dissolve the sugar, until warm. (The temperature should register 95 °F on an instant-read thermometer.)
Pour the milk mixture into a large mixing bowl and sprinkle in yeast. Let stand until the yeast has dissolved, about 5 minutes.
Meanwhile, combine whole-wheat flour, 2 cups bread flour, cracked wheat, oat bran and wheat bran in another mixing bowl.
Give the milk/yeast mixture a stir and add about half of the flour/bran mixture to it. Add salt and beat with a wooden spoon until smooth. Beat in the remaining flour/bran mixture. Gradually add enough of the remaining white flour until you can stir no more.
Place the dough on a floured work surface and knead, adding only enough flour to prevent it from sticking, until the dough is smooth and somewhat elastic, 5 to 10 minutes. (Alternatively, the dough can be mixed and kneaded in a stand-up mixer fitted with a dough hook.)
Place the dough in a lightly oiled bowl and cover with plastic wrap. Let rise in a warm place until doubled, about 40 minutes. Gently punch the dough down.
Coat two 9-by-5-inch loaf pans with cooking spray. Place the dough on a floured work surface and cut it into 2 pieces. Shape into loaves and place in the prepared pans. Cover with greased wax paper or plastic wrap and let rise until loaves are 1/2 to 1 inch above the tops of the pans.
Meanwhile, preheat oven to 350 °F.
Bake the loaves until the tops are brown and the bottoms sound hollow when tapped, 30 to 40 minutes. Remove from the pans and place on a wire rack to cool.