Dissolve yeast in warm water. Stir yeast mixture into buttermilk; mix well, and set aside. Combine flour and sugar; cut in shortening until mixture resembles coarse meal. Add buttermilk mixture; stir until dry ingredients are moistened. Cover and let rise in a warm place until doubled. Or cover bowl tightly, and store in refrigerator until needed. (Dough may be stored up to 3 days.) Punch dough down; turn dough out on a lightly floured surface. Knead lightly 3 or 4 times. Roll dough to 1/2 inch thickness; cut with a 2 inch biscuit cutter. Place biscuits on lighlty greased baking sheets; bake at 450 degrees for 10 to 12 minutes or until lighlty browned. SOURCE: Southern Living Magazine, sometime in 1980. Typed for you by Nancy Coleman.