Pumpernickel (English pronunciation: /ˈpʌmpərnɪkəl/ ; [ˈpʊmpɐˌnɪkəl]) is a typically heavy, slightly sweet rye bread traditionally made with coarsely ground rye. It is often made with a combination of rye flour and whole rye berries.ence, pumpernickel is described as the devil's fart, a definition accepted by the Snopes International Language Database, the publisher Random House, and by some English language dictionaries, including the Merriam-Webster Dictionary. The American Heritage Dictionary adds so named from being hard to digest.