In a large bowl, dissolve yeast in warm water. Add the milk, potatoes, bacon, butter, eggs, sugar, onion, caraway seeds, garlic salt, salt and 3 cups flour. Beat until smooth. Stir in enough remaining flour to form a soft dough.
Turn onto a floured surface; knead until smooth and elastic, about 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and let rise in a warm place until doubled, about 1 hour.
Punch dough down. Turn onto a lightly floured surface; divide in half. Shape each into a round loaf. Place in two greased 2-qt. round baking dishes with straight sides. Cover and let rise in a warm place until doubled, about 40 minutes.
Bake at 350° for 40-50 minutes or until golden brown. Remove from baking dishes to wire racks to cool.