Consuming tree bark might seem unusual, yet it has a long history as a food source for various cultures, particularly in survival situations. Understanding which types are edible and how to prepare them can provide an alternative food option.
Edible Tree Species and Their Bark
The inner bark, specifically the cambium layer, of several tree species can be consumed, offering starches, sugars, vitamins, and minerals. Pine trees, widely distributed, are known for their edible inner bark, which can be eaten raw, boiled, or dried into flour. The Eastern White Pine, identifiable by its needles grouped in bundles of five, is often cited as one of the better-tasting pine varieties for this purpose. However, some pine species like Ponderosa pine should be avoided due to toxicity.
Birch trees, recognizable by their distinct papery bark, also possess an edible inner bark that is often sweeter than other types. It has a reddish color and a sweet, woody aroma. Aspens, particularly quaking aspen, offer an inner bark that can be peeled and eaten, though its taste can be bitter, especially outside of spring. Maple trees, famous for their syrup, also have edible cambium that can be processed into flour or used as a soup thickener.
The inner bark of elm trees, such as slippery elm, is noted for its mild taste, often described as sweet, with less bitterness than evergreens. Willow trees, commonly found near water, also have an edible inner bark. This bark contains salicin, a compound with properties similar to aspirin, which contributes to its bitter taste.
Preparing Tree Bark for Consumption
Harvesting edible tree bark involves careful consideration for safety and sustainability. The edible portion is the inner bark, specifically the cambium layer, located between the outer bark and the wood. The outer bark, which is typically rough and dry, is not consumed. The ideal time for harvesting is often in spring when the sap is flowing, making the inner bark easier to separate.
To collect the inner bark, a small section of the outer bark can be carefully removed. Avoid girdling the tree, which means removing a complete ring of bark around the trunk and can kill the tree. Once exposed, the thin, moist inner layer can be scraped off with a knife or similar tool. This fresh inner bark can be eaten raw, though it might be fibrous.
For further preparation, the inner bark can be dried, either in the sun or near a fire, and then ground into a powder. This flour-like substance can be mixed with other flours for baking bread or used as a thickening agent in soups and stews. Alternatively, strips of inner bark can be boiled to soften them, fried until crispy, or roasted over a fire.
Important Safety Precautions
While certain tree barks are edible, many others are toxic or indigestible, highlighting the need for accurate identification before consumption. Misidentification can lead to severe illness or even death. Trees like oak, wild cherry, yew, black locust, and the manchineel tree have poisonous barks and should never be consumed. The manchineel tree, for example, is highly toxic in all its parts, including its sap, which can cause blistering upon contact.
Allergic reactions are also a concern, as individuals may respond differently to plant compounds. Avoid harvesting bark from areas contaminated with pesticides, herbicides, or pollutants. Consuming bark should primarily be considered in survival scenarios or as a small dietary supplement due to its fibrous nature and the potential for nutrient imbalances if relied upon as a main food source. Always prioritize reliable identification guides; when in doubt, refrain from consumption.