Dissolve yeast in two cups of lukewarm water and milk which has been scalded and cooled; or if so desired the milk may be omitted and all water used; add two and one-half cups of rye flour or enough to make a sponge. Beat well; cover and set aside in a warm place, free from draught, to rise about two hours. When light add white flour, melted butter or oil, two and one-half cups of rye flour to make a soft dough and last salt. Turn on a board and knead or pound it five minutes. Place in greased bowl; cover and let rise until double in bulk, about two hours. Turn on board and shape into loaves; place in floured shallow pans; cover and let rise again until light, about one hour. Brush with white of egg and water, to glaze. With sharp knife cut lightly three strokes diagonally across top, and place in oven. Bake in slower oven than for white bread. Caraway seeds may be used if desired.
By adding one-half cup of sour dough, left from previous baking, an acid flavor is obtained, which is considered by many a great improvement. This should be added to the sponge.