Angel biscuits

5 cups sifted all-purpose flour (preferably a fine southern flour; see headnote)
1 tablespoon baking powder
1 teaspoon baking soda
1/4 cup sugar
2 teaspoons salt
1 cup firmly packed vegetable shortening or lard or a half-and-half mixture of the two
2 cups buttermilk
One 1/4-ounce package active dry yeast dissolved in 1/4 cup very warm water (105° to 115° F.)

1. Preheat the oven to 400° F.
2. Sift the flour, baking powder, baking soda, sugar, and salt into a large mixing bowl. Using a pastry blender, cut in the shortening until the texture of coarse meal. Add the buttermilk and yeast mixture and toss briskly with a fork just until the mixture forms a soft dough.
3. Turn the dough onto a well-floured surface and with floured hands, knead lightly for about a minute. With a floured rolling pin, roll the dough out until 5/8 inch thick; then, using a well-floured 2 1/2- to 2 3/4-inch cutter, cut into rounds. Place on ungreased baking sheets, spacing about 1 1/2 inches apart. Gather scraps, reroll, and cut as before.
4. Bake in the lower third of the oven for 15 to 18 minutes or until the biscuits are nicely puffed and pale tan on top. Serve at once with plenty of butter.