Scald milk; remove from heat, and add butter, 1/2 cup sugar, and salt, stirring well. Let cool to lukewarm (105° to 115°).
Dissolve yeast and 1 teaspoon sugar in warm water; stir well, and let stand 5 minutes or until bubbly.
Combine cooled milk mixture and yeast mixture in a large bowl. Stir in eggs and 5 cups flour; mix well. Dredge raisins in 1/4 cup flour, stirring to coat well; add to dough, stirring well.
Stir in enough remaining flour to form a firm dough. Turn out onto a lightly floured surface, and knead 7 to 8 times. Place in a greased bowl, turning to grease top. Cover and let rise in a warm place (85°), free from drafts, 1 1/2 hours or until doubled in bulk.
Punch dough down; cover and let rest 10 minutes. Turn out onto a floured surface; divide dough into 3 equal portions, shaping each into a loaf. Place in 3 greased 8 1/2- x 4 1/2 x 3-inch loaf pans. Cover and repeat rising procedure 45 minutes or until doubled in bulk.
Bake at 350° for 30 minutes or until loaves sound hollow when tapped. Remove bread from pans immediately, and cool on wire racks. Brush tops with butter.