Pumpernickel

Pumpernickel is a typically dense, slightly sweet rye bread traditionally made with sourdough starter and coarsely ground rye. It is sometimes made with a combination of rye flour and whole rye grains ("rye berries"). At one time it was traditional peasant fare, but largely during the 20th century various forms became popular with other classes through delicatessens and supermarkets. Present-day European and North American pumpernickel differ in several characteristics, including the use of additional leaveners. The less dense North American version may eschew rye grains, have coloring and flavoring agents, added wheat flour, glazed crust, a higher baking temperature, and a dramatically shortened baking time. The word supposedly stems from an old Bavarian term for "hard", either referring to the process used to grind the grain into flour, or the density of the final bread product.[citation needed]

Source: Wikipedia