How to Make It
In a small bowl, dissolve the yeast and the pinch of sugar in the lukewarm water and let stand for 5 minutes, or until foamy. Meanwhile, in a large bowl, mix the flour with the remaining 1/4 cup of sugar. Using a pastry blender, cut in the shortening into the flour until pieces the size of small peas form. Add the yeast mixture and the buttermilk and stir until the dough just comes together.
Turn the dough out onto a lightly floured work surface and knead 5 times; the dough should be soft and moist. Transfer the dough to a clean bowl; cover with plastic wrap and refrigerate overnight.
Transfer the biscuit dough to a lightly floured surface and knead 10 times. Roll out the dough to a 16-inch round 1/3 inch thick. Using a 2 1/4-inch biscuit cutter, stamp out biscuits as close together as possible. Gather the dough scraps, knead 3 times and reroll, then stamp out more biscuits as close together as possible. Discard any remaining scraps.
Lightly butter 2 large baking sheets. Brush the tops of the biscuits with the melted butter. Fold the biscuits in half, brush the tops with the remaining melted butter and set them, unbuttered side down, on the prepared baking sheets. Cover loosely with plastic wrap and let rise in a draft-free place for 2 hours.
Preheat the oven to 400°. Bake the biscuits for about 15 minutes, or until browned on the bottom and light golden on top. Serve warm.