The use of Inner Tree Bark Flour in history (and now?)

In the last few days before Easter, I stumbled upon an article on Linkedin (I am sorry I didn’t save it and cannot share it with you) where they were talking about the use of tree inner bark flour for the production of flavourful bread. I got very curious about it and started thinking about the challenges, compositions, regulatory aspects, and suppliers. I have been asking my connections on Linkedin and searched the web and looked for publications and here is what I have found so far. I am very happy to hear anything you have to say about it.

The tree’s inner bark (phloem) is characterised by a red colour and has a very intense woody aroma. The phloem is living tissue and has cells that can transport water and nutrients to the plant and acts as starch storage. 

When I started asking about tree bark flour, many people said that tree bark is mainly made of compounds that are not compatible with human digestion, and that is correct. It was my mistake, as I was supposed to specify that the inner part of the bark, the phloem, was used to produce this special flour. Compared with the outer bark, the inner bark (phloem) has a lower concentration of compounds that can have anti-digestive effect.

As you might have already understood, the use of phloem for edible purposes is not widely documented. I have learned from my readings that the inner bark of specific trees like Birch or Pine was used historically by the Sami people in northern Scandinavia. They used to harvest the bark from trees that fell for timber, firewood, handcraft, and the phloem was extracted while the tree was still fresh.

The phloem was obtained from the tree trunk, then separated from the outer bark, and left to dry either under the sun or by a fire (or, as it would be done nowadays, in a dehydrator). Once the phloem was dehydrated, they ground it into a fine powder that could be used as flour for bread or biscuits. The inner bark flour does not contain gluten, making the bread quite dense and tough. This and the fact that it would be extremely bitter are the reason why a 100% inner tree bark flour would not be functional in a bread formulation, to obtain an appealing loaf of bread, the inner tree bark flour should be used in combination with other types of flour (usually wheat or rye).

Use of tree inner bark for edible formulations: Sami populations, Native Americans, and more

The Sami populations from Northern Scandinavia are the ones that are linked with the consumption of tree inner bark flour-based products. In the 19th century, the Swedish authorities decided to forbid the harvesting of bark from trees as it was considered dangerous and unhealthy. Regardless of what the Swedish from the 1800s said, it looks like you can eat tree (inner) bark as long as you are using the right part of the bark from the right species of trees (Pine and Birch). 

Alongside the Sami populations in Europe, Native Americans were used to eating and consuming the inner edible layer of tree bark as food and medicine. This was also recorded from the early explorers that visited North America. In the mountains of the New York state, there used to live a tribe called ‘Adirondack’ which means ‘bark eaters’ . As the Sami, they were using primarily Pines and Birch.

Northern Italy

In recent months, tree bark flour was made famous again by an Italian chef, Stefano Basello, who is working in the ‘Il Fogolar La’ restaurant in La Di Moret, Udine, Italy. Following a flood in October 2018, he decided to collect the fallen trees in the Zoncolan area and use the inner bark of Spruce Pine to produce a flour. This flour is then used alongside wheat flour to produce a sourdough that translates into a flavourful bread that reminds the customers of the wood of the Zoncolan forest.

Nothing more romantic than using food to link someone to their roots and history! I just want to specify that only fallen trees have been used and that no trees have been cut to produce this flour.

I have been looking for a commercial supplier of inner Pine or Birch bark flour but you can guess that it is quite challenging to find. Moreover, there are many tree-bark biscuit recipes online where the users can collect and grind their own tree bark flour.

Here is where my story ends, for the moment, and where I ask you to let me know more if you have heard about this type of flour and if you have heard of it being used in some formulations.

I am aware that further reading and better reading must be done but so far, see some of the references:

Zackrisson, O., Ostlund, L., Korhonen, O., and Bergman. The ancient use of Pinus sylvestris L. (Scots pine) inner bark by Sami people in northern Sweden, related to cultural and ecological factors. Vegetation History and Archaeobotany, 9:2. 99-109. July 2000.

Chaney, William R. “Why Do Animals Eat The Bark and Wood of Trees and Shrubs.” Forest and Natural Resources (2003): Purdue University, Aug. 2003.

Huebner, Matt. “Study Shows Metabolic Benefits of Birch Bark.” Next Level Nutrition. 2014.

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