Cream shortening, then add sugar. Beat until light and fluffy. Add eggs, one at a time and beat well after each addition. In another bowl, mix dry ingredients. In a third bowl, mix bananas and sour milk. Add dry ingredients alternately with banana mixture to shortening/sugar mix. Stir in nuts and pour into a greased loaf pan. Bake at 350 for 1 hour.
*Add a small amount of vinegar to fresh milk to curdle.