Sponge Preparation: Dissolve 1 pk yeast in the warm water. Stir in rye flour and caraway seed. Cover bowl snugly with plastic wrap and let stand for 1-3 days. Bake Day Preparation: Sprinkle the remaining package of yeast and remaining 1 cup water on the sponge mixture, blend well. Add molasses, caraway seeds, egg, salt and rye flour and 2 cups of the bread flour. Beat until smooth. Add butter. Stir in remaining flour and mix well either with your hands or in a mixer with dough hooks. Knead for 5-10 minutes. Put in a greased bowl and let rise until doubled in bulk ( about 1 hour) Punch down and let rest 10 minutes. Shape into loaves or put into loaf pans, cover and let rise until doubled. Carefully make slashes on the top of each loaf with a sharp knife or a razor blade, and brush with a beaten egg mixed with a tablespoon of milk. Bake at 375 F for about 40 minutes. This will make 2 large loaves or 3 smaller ones. From *Prodigy's Food and wine Bulletin Board, from Linda Karner, -TNXC18B