Dissolve yeast in water. Into a bowl, sift flour with other dry ingredients. Cut in shortening, add buttermilk, then add yeast mixture. Stir until all flour is dampened. Knead on floured board a minute, roll to desired thickness, and cut with a biscuit cutter. Bake at 400 degrees about dozen minutes. Dough may be kept refrigerated and used about a week. Mrs. Leslie M. Smith