The use of Inner Tree Bark Flour

In the last few days before Easter, I stumbled upon an article on Linkedin. 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, searched the web and looked for publications. 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) has a red colour and has a very intense woody aroma. The phloem is living tissue. It has cells that can transport water and nutrients to the plant and acts as starch storage. 

Many people said that tree bark contains compounds that are not compatible with human digestion. That is correct. But it was my mistake! I had to specify that the it is the inner part of the bark, the phloem, the one that can 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.

The Phloem

As you might have already understood, there is not much evidence for the use of phloem for edible purposes. I have learned that the Sami people (from Northern Scandinavia) historically used the inner bark of specific trees for food production purposes. They harvested the bark from trees that fell for timber, firewood, handcraft. They extracted the phloem 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 and used it as flour for bread or biscuits. The inner bark flour does not contain gluten. This makes the bread quite dense and tough. The bread would be extremely bitter which is why a 100% inner tree bark flour would not be functional in a bread formulation. For bread production, you should use other types of flour alongside inner tree bark 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 consumed inner tree bark flour-based products. In the 19th century, the Swedish authorities decided to forbid the harvesting of bark from trees. They considered it 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 as well consumed the inner edible layer of tree bark as food and medicine. The early explorers of Norther America were among the first to observe this. 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. As a result, 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 in this case, the only trees that they collected were the fallen ones. They did not go around cutting trees to produce the flour.

In conclusion, 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.

Listen to the episode of The Food Science Addict where I talk about my chat with Chef Basello (02×07).

I am aware that I need to look for further information, however, here are some of the references that I have used for this blog post:

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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