Lightly spoon flours into dry measuring cups, and level with a knife. Combine 3 cups bread flour, 1 tablespoon salt, and yeast in a large bowl, stirring with a whisk. Stir in water, 1/2 cup honey, and olive oil. Add 2 cups bread flour, whole wheat flour, and soy flour to yeast mixture, and stir until a soft dough forms. Turn dough out onto a lightly floured surface. Knead until smooth and elastic (about 8 minutes), adding enough of remaining bread flour, 1 tablespoon at a time, to prevent dough from sticking to hands (dough will feel tacky).
Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in size. (Gently press two fingers into dough. If indentation remains, dough has risen enough.) Punch dough down; cover and let rest 10 minutes.
Divide dough into thirds. Working with 1 dough portion at a time (cover remaining dough to prevent drying), roll each portion into a 14 x 7-inch rectangle on a lightly floured surface. Roll up the rectangle tightly, starting with a short edge, pressing firmly to eliminate air pockets; pinch seam and ends to seal. Place each roll, seam side down, in a 9 x 5-inch loaf pan coated with cooking spray. Cover and let rise 45 minutes or until doubled in size.
Preheat oven to 350°.
Bake dough at 350° for 25 minutes or until loaves are browned on bottom and sound hollow when tapped. Remove from pans, and brush tops of loaves with melted butter. Cool on wire racks.