Dissolve yeast in warm water in a small bowl; let stand until creamy, about 5 minutes.

Meanwhile, combine flour, sugar, baking powder, salt, and baking soda in a large bowl. Cut in shortening with a pastry blender until the mixture resembles coarse meal.

Stir buttermilk into yeast mixture until combined, then add to dry ingredients and stir until moistened. Turn dough out onto a floured surface and knead 4 to 5 times.

Roll dough on a lightly floured surface to a thickness of 1/2 inch. Cut out twenty-four 2 1/2-inch-diameter circles. Place circles onto lightly greased baking sheets so they are barely touching each other. Cover and let rise in a warm, draft-free place until almost doubled in volume, about 1 hour.

Preheat the oven to 425 degrees F (220 degrees C).

Bake biscuits in the preheated oven until golden brown, 10 to 12 minutes.