In 2 cup glass measure microwave (high) water 30-45 seconds until lukewarm.
Add yeast to soften.
Stir into flour making a thick, smooth batter. (Cover; rest overnight in warm place.) In a 4 cup glass measure, scald milk with shortening, molasses, sugar and salt about 2-3 minutes (high).
Cool until lukewarm.
Stir the yeast sponge and combine with milk mixture.
Add whole wheat flour, 1 cup at a time, making a stiff dough.
Turn dough onto lightly floured board and knead until smooth.
Divide into 2 equal portions.
Cover with a towel; rest 10 minutes.
Shape into loaves; place in 9x5x3-inch loaf pans.
Cover; rise for about I 1/2 hours, or until double in bulk. (Hurry by placing a 4 cup glass measure boiling water in microwave with bread dough until water cools.
Reheat water and repeat until dough doubles in size.) Microwave (high) 1 loaf, 3-4 minutes, rotating 1/4 turn once or twice as needed for even shaping.
Test for doneness with a toothpick.
Brush with melted butter (optl.) and place under a hot broiler element 1-2 minutes to brown.
Cool 10 minutes.
Remove from pan, cool on rack.