Bark bread
During the 18th and early 19th century Northern Europe had several very bad years of crop failure. This was  particularly during the Little Ice Age of the mid 18th century. The grain harvest was badly affected. Many ideas to make the flour last longer were introduced. In 1742, samples of “emergency bread” were sent from Kristiansand, Norway to the Royal Administration in Copenhagen. One of these was bark bread. This is bread made from grain husks and bread made from burned bones. During the Napoleonic Wars, moss too was used for food.