In a small bowl, dissolve yeast and sugar in warm water. Let sit for 5-10 minutes until yeast mixture is bubbly.

In a large bowl combine butter, salt, and 1c. whole wheat flour.

Add the yeasty mixture to the whole wheat flour mixture. Mix well. Stir in the white flour ½ cup at a time, mixing well after each addition.

When the dough has pulled together, turn it out onto a lightly floured surface and knead until smooth and elastic, about 8 minutes.

Lightly oil a large bowl, place the dough in the bowl and turn to coat with oil. Cover with a damp cloth and let rise in a warm place until doubled in volume, about 1 hour.

Deflate the dough and turn it out onto a lightly floured surface. Form into a loaf and place into a lightly greased 9x5 inch loaf pan. Cover the loaf with a damp cloth and let rise until doubled in volume, about 40 minutes.

Preheat oven to 375 degrees.

Bake at 375 degrees for about 30 minutes or until the top is golden brown and the bottom of the loaf sounds hollow when tapped.