Activate yeast by combining warm water and yeast in a bowl for about 5 minutes until frothy.
In another bowl, whisk together whole wheat flour, all-purpose flour, baking soda, and salt.
Pour the yeast mixture into the dry ingredients along with honey and melted butter; mix until a sticky dough forms.
Knead on a floured surface for about 8 minutes until smooth and elastic.
Place dough in a greased bowl, cover, and let rise in a warm area for about an hour or until doubled.
Punch down the dough, shape into two loaves, and place in greased loaf pans; let rise again for about 30 minutes.
Preheat oven to 350°F (175°C); bake loaves for approximately 30 minutes or until they sound hollow when tapped.