Mix dry ingredients. (You may use some whole wheat flour in place of white flour.).
Cut in the shortening with a pastry blender or knives.
Dissolve the yeast in the warm water.
Add buttermilk and yeast mixture to the dry ingredients and stir to blend.
Bring dough together on a floured surface and kneed lightly. (No more than 12 times - this is the key to keeping the biscuits light.).
Roll or pat to 1/2 inch thick.
Cut into 3 dozen biscuits.
Bake at 450 for 10 - 12 minutes.
Alternately, place unbaked biscuits on a parchment paper covered baking sheet. Freeze until solid. Store in freezer bags. When you want to use them, remove from freezer and allow to defrost on a baking sheet before baking at 450 for 10 - 12 minutes.