Combine flour, 1 cup buttermilk and butter in a food processor until
a ball forms. If dough is too thick, add more buttermilk, but it should
be thick enough to form a ball. Place in a bowl, cover with a towel
and leave in a warm place for 12-24 hours.
Combine water, yeast and honey in a small bowl and leave for 5 minutes or until it bubbles. Add salt and baking soda and mix well. Place half the flour mixture, half the yeast mixture and ½ cup unbleached white flour in a food processor. Process until a smooth ball forms. Repeat with the other half of dough, yeast mixture and white flour.
Knead the two balls together briefly and place in a buttered bowl.
Cover with a towel and let rise 2 hours, until doubled in bulk.
Punch down, cut the dough in half and process each half in a food
processor for30 seconds each.
Form into loaves and place in buttered loaf pans (preferably stoneware). Cover with a towel and let rise 1-2 hours, until doubled.
Bake for 30 minutes at 350 degrees.
Cool on racks.
This is a good compromise bread that can be sliced and used for sandwiches.
Yeast is used, but the flour is soaked in buttermilk first.