Soften the yeast in the warm water and set aside. Heat the cottage cheese to lukewarm in a large bowl in the microwave. Stir in the dill, onion, sugar, butter, salt, dill seed and baking soda. Stir in the yeast mixture and 1 cup of all purpose flour and 1 cup of whole wheat flour to form soft dough. Knead in the remaining flour on well-floured board, adding more all purpose flour if necessary. Place the dough in a greased bowl and cover with plastic wrap sprayed with cooking spray. Let the dough rise until doubled in size (about an hour). Stir down the dough and turn it into well-greased loaf pan. Let the dough rise again for 30 minutes in a warm place. Bake at 350 for 35 to 40 minutes or until top is a deep golden brown color and the loaf sounds hollow when tapped. Brush with additional butter and sprinkle with salt, if desired.