Dissolve yeast in warm water; add 1 tsp sugar until frothy.
In the bowl of a stand mixer fitted with dough hooks, combine starter, yeast mixture, oil, honey, eggs and 2 cups wheat flour. Mix well.
Add baking soda mixed with flour and salt. Mix well.
Add bread flour, one cup at a time.
Using the stand mixer, knead with dough hooks for 10 minutes.
Grease a large bowl and place the dough in the bowl. Cover with a cloth and place in a warm place to rise until double in size, about an hour.
Shape dough into two loaves and place them in two greased bread pans. Cover the dough and let rise in a warm place for another 20-30 minutes.
Bake at 350° for 30-35 minutes.
For a soft crust, brush the top of the loaves with butter while they are still warm. Allow the bread to cool and slice to serve.
Store any remaining bread in an airtight container.