Dissolve yeast in warm water, stirring well; let stand 5 minutes or until bubbly.
Scald milk; add shortening, sugar, and salt, stirring until shortening is melted. Add water; let cool until mixture is lukewarm (105° to 115°). Stir in dissolved yeast. Gradually stir in enough flour to make a soft dough.
Turn dough out onto a heavily floured surface, and knead 8 minutes or until smooth and elastic. Place dough in a greased bowl, turning to grease top. Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in bulk.
Punch dough down; turn out onto a floured surface. Divide into 4 equal portions, shaping each into a smooth ball. Cover; let rest 10 minutes.
Shape each portion into a loaf; place in 4 greased 8 1/2- x 4 1/2- x 2 1/2-inch loaf pans. Cover and repeat rising procedure 45 minutes or until doubled in bulk. Bake at 375° for 35 minutes or until loaves sound hollow when tapped. Remove bread from pans immediately; cool on wire racks.