Combine the yeast, whole wheat flour, all purpose flour, baking soda, salt, honey, oil, and buttermilk into pan of a bread machine.
If baking in bread machine use medium temperature setting.
If baking in an oven, use manual or dough cycle to knead dough. Remove from bread maker, and place in a greased loaf pan. Let rise until doubled in size. Bake in a preheated 350 degree F (175 degree C) oven for 25 minutes, or until bottom of loaf sounds hollow when tapped.