Bark bread

Bark bread is a form of bread used during a famine. It made by adding ground phloem to the flour as an to make it last longer.
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 and bread made from burned bones. During the Napoleonic Wars, moss too was used for food.
The last time bark bread was used as famine food in Norway was during the Napoleonic Wars. The introduction of the potato as a staple crop gave the farmers other crops when grain production failed. So that bark bread and moss cakes were no longer needed. In Northern Sweden, traces of Sami harvest of bark from Scots pine are known from the 1890s. In Finland "pettuleipä" (literally "pinewood-bark bread") was produced as a substitute for bread during the Finnish Civil War of 1918.