Add About 3-4 Cups of additional whole wheat ½ cup at a time to the mix and the sponge, graduating from a wooden spoon to hand mixing, as the dough thickens.
When all the flour is added, turn out the dough onto a floured surface. Knead 15 minutes, add small amounts of flour if the dough persists in stickiness.
Return the kneaded dough to an oiled bowl and cover with a towel until its bulk has doubled (about 1 hr.)
Punch down the risen dough, turn it out onto a floured surface, and knead it again for 10 minutes.
Form your desired loaves, cover with a towel and let rise until doubled in bulk one more time.
Preheat oven to 375.
Brush with melted butter just before, and after, baking.
Bake 30-40 minutes or until the loaves sound hollow when tapped. If using bread pans, remove the loaves right away so the crust can crispen. Let the loaf cool before diving in!