Step 1: In large mixer bowl, combine 5 cups of all-purpose flour, yeast, sugar and salt, mix well. In saucepan, heat water and shortening until warm (110 to 120 degree for dry yeast) (80 degree for fresh yeast); the shortening does not need to melt.
Step 2: Add shortening mixture to flour mixture; beat 3 minutes at medium speed. Add egg whites. By hand, gradually stir in remaining flour and enough flour to make a firm dough.
Step 3: Knead on floured surface about 5 minutes. (Dough will be slightly sticky.) Place in greased bowl, turning to grease top.
Step 4: Cover; let rise in warm place until double, about 1 hour. Punch down dough. Divide into 4 evenly pieces.
Step 5: On lightly floured surface, shape each into a round loaf and place into 8 inch round cake pan. Cover; let rise in warm place until almost doubled, about 30 minutes.
Step 6: Spray tops of loaves with water and bake at 400 degrees for 35 to 40 minutes until loaves sound hollow when tapped. Remove from pan and cool.