Feather Light Biscuits

1 package dry yeast
2 tablespoons warm water
5 cups all-purpose flour
1-tablespoon baking powder
1-teaspoon baking soda
1 ½ teaspoons salt
1 cup shortening
2 cups buttermilk
Butter or margarine, melted


Dissolve yeast in warm water. Let stand 5 minutes. Combine flour and next 4 ingredients in a large mixing bowl. Cut in shortening until mixture resembles coarse meal. Add buttermilk, mixing well. Stir in yeast mixture. Turn dough out onto a lightly floured surface and knead 1 to 2 minutes. Roll dough to ½-inch thickness. Cut with a 2-inch biscuit cutter. Place biscuits on a lightly greased baking sheet. Brush tops with melted butter. Bake at 400 degree for 15 minutes.