Mix and knead together all of the ingredients--in a bowl, mixer, or bread machine--to make a smooth, but quite sticky dough. (Polysaccharides in pumpernickel called pentosans are responsible for this stickiness; they?re the reason rye dough will never att
Transfer the dough to a lightly greased work surface, and gently deflate it. Shape it into an 8-inch log, and place it in a lightly greased 8 1/2 x 4 1/2-inch loaf pan. Cover the pan, and allow the loaf to rise till it?s crested a good inch or so over the
Bake the bread in a preheated 350°F oven for 35 to 40 minutes, until an instant-read thermometer inserted into the center registers 190°F. Remove the bread from the oven, and turn it out of the pan onto a rack to cool.