In a small bowl, combine the yeast and warm water; set aside. (Note: It is important to use warm water here. Hot water will prevent the yeast from activating.)

In a large bowl, add the flour, sugar, salt, baking powder and baking soda; stir until well combined.

Using a pastry cutter or two table knives, cut the shortening into the dry ingredients until it becomes the size of small peas.

Stir in yeast mixture and buttermilk; toss until just combined.

Turn dough out onto a well-floured countertop and fold several times.

Roll dough into a circle about ¾” thick.

Using a 2” biscuit cutter, cut biscuits and place close together on a baking sheet. Cover biscuits lightly and let rest at room temperature for 30 minutes.

While biscuits are resting, preheat oven to 400°F.

Bake at 400°F for 14-16 minutes, or until light golden in color.

Brush biscuits with melted butter before serving.