Updated: Mar 12, 2019
I had mostly always heard that white oak (Quercus alba) is not a good bark for tanning. My guess is because it may be lower in tannins than the bark of other species of oak. Most of my experience so far using oak bark has been of black oak (Quercus velutina), which produces a vibrant, deep maroon leather, which I love and highly recommend.
This large, very much alive, white oak tree (of at least 2 ft in diameter), was recently taken down at some friends’ property to make space for the building of a cabin. All of my experience harvesting oak bark so far has come from large trees taken down for safety or building or brought down by storms. So I jumped at the chance to harvest the bark from this tree while it was still green. Remember, even if someone is going to use oak for firewood, it makes no difference for burning whether or not the wood has bark on it. Definitely take the opportunity to strip that bark before the wood is split! Often friends or acquaintances will be glad to let you do this.
This Quercus alba was felled and the bark stripped in July in Western North Carolina, while the tree was fully leafed out. The green inner bark tasted moderately tannic--good enough to harvest, though certainly not the strongest I’ve ever tasted. While harvesting, the green inner bark was very blond in color, and the metal from iron draw knives & hatchet stained it purple and purplish pinks (these colors, so I’ve once heard, are good to make note of, as they can be indicators of various kinds of tannins, so I take note. I think all of the species of trees from which I’ve ever harvested bark and noticed coloration have reacted with iron in the pink-purple-blue range. So far no greens.) Once harvested, much of the blond inner bark oxidized to a light or medium-light brown color over the next several days of drying open air and in the sun. Because this inner bark was so light colored I suspected it might make a beige colored leather.
I love using squirrel hides as tests for new tanning plants. They’re small, they tan quickly (in under a week usually), they only require a small pot of tanning liquid, and their skin is robust enough that it makes a very sturdy, surprisingly thick leather with beautiful grain which is very nice for crafting small pouches and wallet sized sort of things. Sometimes I almost think that squirrel leather with the hair off, grain-on is even more beautiful than a fur-on squirrel!
This Eastern grey squirrel hide was bucked in a solution of wood ash, the hair and epidermis removed, and then rinsed in preparation for tanning.
I boiled a small pot of the oak bark, simmered it for under half an hour, and let it steep, covered, overnight, as is my typical method (A slower cold infusion probably would have worked great as well). By the next day, I was surprised at how deep red colored the tannin solution was! The solution looked typical of other oak barks, and had a similar very earthy and rich aroma. The solution also impressed me with how strong it tasted (by which I mean how astringent it tasted).
The first day in solution, the squirrel hide took on a warm, orangey-beige color. Over the course of a week of tanning, this color darkened to a medium brown, which was much darker than I expected.
Another note, is that the one-time-boiled oak bark from this solution, once placed in a pot of fresh water and left covered in the Summer sun, took about 4 to 5 days to leach out the remainder of its tannins. This created a lighter orangy solution of a decent (read moderate to moderate-low) strength (by strength again I mean the astringency by taste), certainly usable and worth the while. The bark tasted very spent at that point, and I would say not worth further boiling or soaking. So this same method I would use with a larger batch of solution.
After rinsing well, and oiling & softening (I used pig lard to oil the hide), the leather turned out a slightly reddish, very rich colored medium brown with a very shiny grain. The leather is both supple and tough, and I call the grain color super attractive! In all ways thumbs up for white oak bark! I plan to use this batch of oak bark next on a deer hide. I think it would also be great for hair-on hides like sheep.
Use the lesser-sought. Celebrate the life and uniqueness of every plant. Receive the gifts and opportunities that come to you, especially through the cycles of death and discarding that happen all around us the way the earth today turns. Go to the dumpsters, the tree surgeons and the arborists just as much, if not more, than you would go to the woods. Especially regarding the use of tree barks for tanning, the avenues of harvest that I believe make the most sense in our world have changed. I don’t go to the woods and say, “I’ve heard that chestnut oak is the best for tanning. I’m going to go find and cut down a chestnut oak.” Instead I use what has already fallen, what must come down for firewood, for building, or for other things, and what is already close to death. Experimenting with every new plant in tanning is a scientific adventure and also a magical and (to me) very exciting journey. It is always worthwhile. We’re building the tanning practices of a harmonious world, which is small scale and rooted into the specific climate and ecologies of each place. Listen from the inside, and go with gentleness and imagination as you go.
~Victoria, August 2018, Sodom Laurel NC