Mix 3 1/2 cups of the flour, the sugar, salt, shortening and yeast in a large bowl. Add warm water. Beat with electric mixer on low speed 1 minute, scraping bowl frequently. Beat on medium speed 1 minute, scraping bowl frequently. Stir in enough remaining flour, 1 cup at a time, to make dough easy to handle.
Turn dough onto a lightly floured surface. Knead about 10 minutes or until smooth and elastic. Place in a greased bowl and turn greased side up. Cover and let rise in warm place 40 to 60 minutes or until double. Dough is ready if indentation remains when touched.
Grease bottoms and sides of 2 loaf pans, 9x5x3 or 8 1/2x4 1/2x2 1/2 inches.
Punch down dough and divide in half. Flatten each half with hands or rolling pin into a rectangle, 18x9 inches, on a lightly floured surface. Roll the dough up tightly, beginning at 9-inch side, to form a loaf. Press with thumbs to seal after each turn. Pinch edge of dough into roll to seal. Press each end with side of hand to seal. Fold ends under loaf. (*Freeze at this point wrapped in plastic wrap, if baking later.) Place seam side down in a pan. Brush loaves lightly with butter. Cover and let rise in warm place 35 to 50 minutes or until double.
Move oven rack to low position so that tops of pans will be in the center of the oven. Heat oven to 425°F.
Bake 25 to 30 minutes or until loaves are deep golden brown and sound hollow when tapped. Remove from pans to wire rack. Brush loaves with butter; cool.
*To make frozen dough later, remove dough from the freezer. Unwrap and place in prepared pan, as above. Thaw overnight in the refrigerator. Remove to a warm place and allow to rise until doubled. Bake as directed above.