The grain harvest was badly affected, and creative solutions to make the flour last longer were introduced.

[6] In Northern Sweden, traces of Sami harvest of bark from Scots pine are known from the 1890s, and, in Finland, pettuleipä (literally "pinewood-bark bread", made with cambium [phloem] flour) was eaten in Finland as an emergency food when there has been a shortage of food, especially during the Great Famine of the 1690s,[7] during the second famine of the 1860s, and, most recently, during the 1918 civil war.

The yellow or green inner bark (depending on tree species) was dried over open fires, in an oven, or in the sun.

Erik Pontoppidan, the bishop of Bergen, Norway in the mid-18th century, recommended using elm, as it helped the often crumbly bark bread hold together better.

Another problem is that the yeast cannot break down the ground bark; as a result, the bread will not leaven properly, and will be hard and not hold together well.

Both the bishop Pontoppidan and others blamed the high mortality during the famine of the 1740s on the "unhealthy bark bread" and general lack of food.