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CHAPTER 1

Inspired by Beavers

After my oak barrel epiphany, I started to become slightly obsessed with discovering the flavor of wood. For weeks I researched every source I could think of, searching the web and talking with friends and colleagues, as well as many food producers and scientists. Each conversation contributed another idea, insight, or clue. Soon, it became increasingly apparent that there was no single answer. Some sources strongly supported the thesis that wood affects the food products it comes in contact with; others categorically disagreed. To complicate things further, those that did note the influence (and these affirmers only existed in the realms of wine and spirits) were split into two camps: One deemed the influence of wood to be very positive, and the other thought it was altogether a negative thing, ruining the flavor of a given food item. After a while it also became clear that most took "wood" to mean "oak"; no other species of tree was discussed, particularly when it came to storage barrels.

Determined to find conclusive evidence of the flavor of wood, I continued with my research, always hoping to find the one lead that would definitively confirm — or deny — my hypothesis that wood did indeed flavor our foods. Quite to the contrary, though, every source I consulted just led in another possible direction.

Frustrated with my lack of progress, I decided to visit my parents in Nova Scotia, Canada, where I had spent most of my childhood summers hiking and canoeing. With its vast forests and seemingly endless waterways and lakes, it was the perfect place to clear my head: There is nothing more beautiful and relaxing than wandering through the aromatic, evergreen canopy of towering white pine, hemlock, and maple trees alongside lively streams and glassy lakes, particularly during a crisp autumn morning, when you get out on the lake before sunrise in your canoe, gliding silently through the landscape. Surrounded by mist rising from the water, you can watch as nature slowly wakes up around you. Birds make their first short morning flights from tree to tree. Deer stand close to the water's edge for a drink. A family of river otters, returning from a night of hunting, noisily splashes into the lake.

On one especially picturesque, early-morning canoe trip during my visit, I met a family of four beavers munching away on the shoreline vegetation. I was delighted to see them, but the feeling wasn't mutual, as they stated loud and clear by forcefully splashing their tails on the water's surface before making a dive for it. On my treks I'd regularly come across their dams, which were masterfully crafted to keep all entrances to their burrow underwater, thereby making it very hard for any enemies, as well as the cold air, to enter. Constructed from nearby tree limbs, sticks, mud, stones, and other vegetation, these dams can last for centuries and change landscapes profoundly. The architectural capability of a beaver, I reflected, was probably unmatched by any other single animal on this planet, humans of course — and unfortunately — excluded. And they do all this hard work in cold water, on a diet consisting mostly of trees.

Then it hit me — this could be the one lead I had been looking for! Who better than beavers to address questions regarding food and trees? They basically chew trees for a living — and, judging from some pictures, can even get quite fat off them.

As perfect as this source might seem, there was one fatal flaw. How would I communicate with an animal that likes to swim extensively in cold water, preferably during nighttime, chews trees with iron-colored and reinforced teeth, reingests its feces for optimal nutrient extraction, and purposefully floods its home? There is literally no common ground between the behavior of beavers and humans.

After a bit of thinking I came to the conclusion that I had to resort to studying their behavior to make assumptions about their likes and dislikes in trees. At first sight, judging from the small trees and bushes cut down around their dams, they were not very discriminating. Vicinity rather than taste preference seemed to have been the main deciding factor in their choice of wood. Yet when I took a closer look at what tree species were actually used in the building of the dams and compared them to the ones missing from the banks, there were a few noticeably absent. (I would later read that this had to do with the beavers' so-called "central-place foraging behavior," where they would not eat small trees, branches, and bushes at the place of growth but would rather bring them back to a specific central place — their burrows — for consumption. This meant that they had brought the trees of their liking back to their burrow while they used the ones they didn't like to eat for the construction of their dam.)

Some large, heavy trees that were impossible to move back to their burrow had all their bark chewed off, while some (probably the unappetizing ones) still had all their bark. Following one particular construction project — a dam that suffered some damage after strong rainfalls and had to be partly rebuilt — I could narrow down which trees were missing and which were debarked. Wild raisin and dogwood seemed to be only used as building materials, while evergreen trees like larch, spruce, and balsam fir were understandably shunned completely. Why? Imagine you had only your teeth to cut down a tree. Which one would you prefer: the sticky one that freshens your breath, yet won't allow you to open your mouth for days, or the one that doesn't glue your teeth together? As it turned out, my not-very-scientific observations about a single dam were confirmed by scientific literature and internet sources alike. I had found the beavers' preferred trees: willow, poplar, maple, and birch.

Now to the question of taste. How do you taste a tree? Here, the beaver inspired me again. He only eats the bark and the nutrient-conducting underlying cambium, the layer sandwiched between the outer bark and the inner hardwood. Furthermore, he is known for being a bit of a tree connoisseur; he actually tastes the bark of a tree before deciding to use it. This casual tree-tasting approach of the beaver became my shared plan of attack. Knowing that the bark from mature trees would be very tough, and also to avoid damaging them, I opted to taste samples from young trees growing in ditches that were regularly cleared. Thanks to a knife (my replacement for the beaver's iron-reinforced teeth), I obtained a small piece of bark, cambium included, from each of the four trees and simply tried them.

I expected it to be a rather unpleasant experiment, but most surprisingly, it wasn't. The poplar bark initially tasted faintly like rhubarb and then grew more bitter, but still with a hint of sweetness that strongly reminded me of Manuka honey (honey made from the flowers of the Manuka tree, native to New Zealand and with antibacterial and antioxidant properties). The birch bark had a very crunchy texture and tasted surprisingly like salad greens, while the maple bark had, unexpectedly, no taste whatsoever. The most unpleasant one was the willow bark, which tasted like green potatoes still covered in some soil. Altogether, it was fascinating to discover how very different tree barks taste and how varied the beavers' taste landscape actually is.

But I suspect I was not the first person to observe animals eating bark and decide to sample it as well. Tree bark in general has had a hugely important role in human history. Most aboriginal people from Africa, Asia, Australia, Europe, and the Americas have used it for a myriad of purposes, including for making clothing, pots, paper, medicine, fibers for fishing lines and nets, and wrappers for cooking. The Native Americans' use of birch bark for the outer skin of canoes and their tipis is probably best known, but the Aboriginal Australians also used eucalyptus bark for making canoes and shelters. Native Americans made their own tobacco from willow bark (simultaneously taking advantage of its analgesic effects thanks to the presence of acetylsalicylic acid, more commonly known as Aspirin) and dyed their cloth a brownish red with alder bark.

More importantly and interestingly for this book, in addition to their many uses of tree products, several North American tribes were actually eating trees or parts thereof. This tradition, which was first described in 1792 by the trader and explorer Alexander MacKenzie and a little later by members of the famous Lewis and Clark expedition, has even found its way into modern vocabulary The word "Adirondack" stems from the old Mohawk Indian word atirú:taks, meaning "tree eaters." The Mohawks used this word to speak in a rather derogatory fashion about some Algonquin tribes who were known to eat tree bark. More specifically, they were not eating the bark itself but rather the soft cambium underneath, which was rich in carbohydrates, vitamins, fiber, and minerals. Harvesting of the bark happened only in springtime (the Coeur d' Alene people called May the "bark loose on tree month") and mostly focused on trees from the pine genus. Other tribes were also known to dry the cambium of hemlock and spruce trees and then grind it into a kind of flour used in the making of a specific cake.

Using pine cambium for food was also a tradition practiced by the indigenous Sami people of Scandinavia. Considered quite a delicacy and brought as a special gift when visiting relatives living in pine-free areas, it was the perfect complement to their protein-rich diet. Also, due to its high vitamin C content, it kept them from getting scurvy. By today's definition, pine cambium would have definitely been branded a "superfood."

I am almost certain that the first Native Americans and their Scandinavian counterparts who thought of bark as food had previously observed the natural behavior of beavers. They basically had started from the same point as I had, yet they had obviously spent much more time finding the best method for eating trees. Namely, they did not eat the bark as a whole but only the soft cambium that lies beneath, and even that only in springtime, when it's most tender.

Of course, I wanted to sample cambium immediately. However, it didn't feel right to partly or fully cut a pine tree just for tasting purposes. Also, it wasn't spring. And as the edibility of pine cambium had already been proven by a wealth of sources, I wanted to try something new anyway. So I returned to the four saplings I had already cut and carefully separated some soft cambium from the tough outer bark. Disappointingly, it didn't taste very different from the whole bark. The flavor was slightly milder and the cambium was softer and easier to chew, which reminded me of a survival technique I'd heard of many years before: If you were to find yourself stranded in a remote woodland without any food, it is supposedly possible to make a kind of spaghetti from birch cambium strips cooked in boiling water. Would this transform the raw taste of the bark or cambium?

Conveniently, I had already cut the cambium into narrow strips, and a pot with boiling water was quite easily procured. I threw the birch cambium into the boiling water and tried it at regular intervals to see if it had become softer. After a full hour and a half of cooking, however, there still weren't any significant changes in texture or taste, so I declared the experiment a failure and considered my options. If boiling didn't work, I wondered if I would have better luck with frying. I got out one of my older cast-iron pans and added a bit of rapeseed oil, which has very little flavor on its own and is therefore perfect for taste experiments. Once the oil reached frying temperature, I threw in some freshly cut birch cambium. A quick and quite fragrant sizzle later, I held the first golden-brown birch cambium strip in my hand.

Tasting it was a real revelation. Crunchy and brittle, the cambium was actually as easy to eat as a vegetable chip. It had completely lost its salad-green taste and was now sweet and starchy, with the tiniest hint of a quite pleasant bitterness. After I added a bit of salt, I began to see it as a real alternative to the bag of potato chips I buy every once in a while. Only some tiny woody bits randomly dispersed in the cambium (quite similar to those found in pears) felt a bit strange to swallow; however, they were not a real deterrent. If I had harvested the cambium at the right time in spring, the wooden bits would be likely nonexistent.

Seemingly having found the best way to prepare tree cambium, I was eager to also give the others — namely willow, maple, and poplar — a try. However, after having cut some fresh cambium from all three trees and frying them in fresh oil, I would soon find out that they simply weren't up for the task, as they became only chewier and bitterer. (This was probably why the Native Americans hadn't used them in the first place.)

After tasting many different tree barks prepared in a number of ways, I was very surprised to see how diverse they actually were. Yet when trying to think of a shared flavor note, only bitterness came to mind. Now, bitterness isn't normally a desired taste. For us humans, it immediately sets off alarm bells, as many poisonous plants taste bitter. Yet it is not always a negative thing.

This is probably best demonstrated by the worldwide popularity of tonic water, the essential component of every gin and tonic. Originally patented under the rather clunky name "improved aerated tonic liquid" by a Londoner named Erasmus Bond in 1858, its invention goes back to British officers and citizens stationed in India and other tropical outposts of the British Empire. For them, however, it wasn't considered to be a beverage drunk for pleasure but rather a necessary medicine for daily survival. Colonizers in the tropics faced a mortal threat from an unexpected enemy: tiny mosquitoes, or rather the diseases they carried. Chief among these was malaria, much fiercer than the strains encountered in Europe.

Yet the tropics also offered a cure for the dangerous infection: the bark of the cinchona tree. Originally discovered by the indigenous people of what is today called Peru, and therefore called "Peruvian Bark" (or "Jesuit's Bark" after those who first conveyed the bark to Europe in the seventeenth century), it quickly became the most effective drug against malaria. Initially the bark was simply ground up whole, but in the 1820s its active component, called quinine, was isolated and soon after dispersed as white quinine powder to all colonies in the tropics. In the 1840s British soldiers and citizens used 700 metric tons of cinchona bark annually, as it had been discovered not only to cure malaria but also to prevent it. The quinine powder was, however, so bitter that people were soon looking for ways to make it more palatable by mixing it with soda water and sugar. Born was the first rudimentary version of tonic water — and probably also that of the gin and tonic. Both remain hugely popular to this day, proving that the bitterness of tree bark is not an altogether negative thing.

Yet bitterness was just the common flavor connecting all the types of bark. Individually, they had a range of flavors that I described to myself as tasting like rhubarb, Manuka honey, salad greens, or even green potato. That method worked well for my personal records, but what if I had to describe the flavor to someone who had never tasted Manuka honey or green potatoes before? How could he or she possibly know what I was talking about? The straightforward answer is that they wouldn't. The lack of vocabulary to describe flavor in Western society was beginning to pose a large problem for me as I embarked on my quest to identify the flavor of wood.

The Issue of Flavor

The languages of Western cultures (in stark contrast to those of many Asian, African, and South American cultures) are seriously lacking in vocabulary when it comes to matters of taste. We simply have very few words at our disposal to describe the taste and smell of food — or other things, for that matter.

How is this possible? After all, it has been a hundred thousand years since our ancestors developed the necessary anatomical preconditions (a more developed larynx and vocal cords) to voice even complex words like Worcestershire or, one of my personal favorites, squirrel. How can it be that we don't have the words to adequately describe the flavor of a strawberry, much less the one of tree bark?

Already in classical times, philosophers from Aristotle onward developed a hierarchy of the senses. Senses which can perform at a distance, such as sight and hearing, were admired and regarded as more objective. Those that required closer contact, including taste, touch, and smell, were shunned as being carnal, animalistic, and subjective. This attitude toward taste continued throughout the centuries and had devastating linguistic effects. Taste was considered useless to the progress of knowledge and became associated with gluttony. The result was that no particular popular vocabulary was developed to describe the taste of foods. While scholars like Giorgio Vasari wrote entire books expressing their opinions on visual art or music, no such thing was done for food. Instead, there were books on manners, which stated that it was extremely rude to talk about one's personal preferences (that is, tastes) while sitting at the table.

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Excerpted from "The Flavor of Wood"
by .
Copyright © 2019 Artur Cisar-Erlach.
Excerpted by permission of Abrams Books.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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