Combine flour, soda, and sugar; cut in shortening and stir in yeast and buttermilk. Be sure to mix well. Keep covered in refrigerator at least an hour or two before using. Roll out and cut as desired. Plae on greased pan. Let rise for 2 hours. Bake at 230ºC for about 10 minutes. NOTE: Dough will keep in refrigerator as long as a week.