In a large bowl, add yeast to warm water. Stir until dissolved. Add salt(optional), sugar, shortening and warm milk. Stir. Mix in 2 cups flour. Add more flour until dough chases around bowl. Turn dough out on floured board. Knead until smooth. Put in greased bowl then flip up. Rise x 1 hour. Punch down and let rise again. Put in greased bread pan. Preheat oven to 375*. Bake x 45 min.