1 pkg (approx. 2 1/4 tsp.) dry yeast
1/4 cup warm water

5 cups flour
1/4 cup sugar
3 tsp. baking powder
1 tsp. baking soda
1 tsp. salt
1 cup shortening
2 cups buttermilk or sour milk

Dissolve yeast in warm water and set aside. 
In large bowl, stir together flour, sugar, baking powder, baking soda and salt.  Cut in shortening.  Add yeast and water mixture, and buttermilk.  Stir well with a wooden spoon.  This will be sticky dough.  Cover and keep in the refrigerator for up to 2 weeks, taking out as you need it.  To make biscuits, use a well-floured board (the dough will be sticky!) and pat out as much as you want.  Cut into rounds and bake at 400* for about 15 minutes or lightly browned on top.