Opening scene from The Tale of Princess Kaguya, the breathtaking animation by Isao Takahata retelling the Japanese folktale The Tale of the Bamboo Cutter (Nishimura 2013).
I was shopping at my local Chinatown when I spotted them, piled up in a cardboard box nestled between the hay-covered lotus root nodes and the warty squashes : lovely winter shoots, shaped like rhinoceros tusks, and seemingly as tough, too. Their overlapping leaves were soft and shiny, like the flanks of a well-groomed horse. After this brief tactile exploration, in which two such tusks found temporary rest with the hairy taro roots at the bottom of my shopping basket, I ceded this much coveted standing space among the boxes of produce for other shoppers to uncover their own edible treasures.
Edible, is, of course, a conditional term, dependent at times on the buyer’s knowledge of his bounty. Of fresh bamboo shoots, I had none, but I was willing to bet instead on my determination, and on the sometimes contradictory advice of my indispensable side-kick: the Google search engine. Indeed my cooking pots and knives had never seen the likes of these layered tusks. I had a vague recollection of buying a can of bamboo shoots once, and being so repulsed by the formaldehyde-like smell that I vowed never to buy them again.
The glowing bamboo shoot from which Princess Kaguya is about to emerge, to the astonishment of the bamboo cutter (Nishimura 2013).
I love the thrill of buying an unfamiliar vegetable, and then getting home and figuring out how to prepare it. Some vegetables pose less of challenge than others. If you buy a mysterious leafy green vegetable from Chinatown, chances are, you can steam, blanch or stir fry it. If you buy a strange-looking winter squash, chances are, it will become tender and delicious if you bake or simmer it.
I should have known that the procedure for transforming my leafy rhinoceros tusks into the tender juicy strips that so please the palate in Asian stews and stir-fries did not belong to this latter category. The ubiquity of the canned version, and the scarcity of the fresh shoots begged the question: who buys fresh bamboo shoots? There must be a reason why most recipes that call for bamboo shoots call for canned bamboo shoots, with no mention of any alternative. I started to wonder if the food industry would have us believe that, like my MSG-addicted curry cows, cans of bamboo shoots are picked ripe from large orchards where the trees are watered with brine tinged with citric acid (and maybe also formaldehyde?).
The young Princess Kaguya, nicknamed Takenoko (bamboo shoot) due to her rapid growth, crawling between the stalks of bamboo (Nishimura 2013).
Back at home, my tusks protruding pointedly from the canvas bag on my countertop, I waited patiently for my side-kick to regurgitate his barrage of schizophrenic advice, and then sifted through the results (with growing impatience).
Different bamboo-eating cultures, and indeed bamboo-eating families, have their own way of processing bamboo shoots, and reading more into the science of bamboo shoots, I reasoned that there may be more to it than cultural idiosyncrasy. There are many hundreds of species of bamboo, a small but substantial subset of which are consumed by humans. All of these, however, are highly toxic in their raw form, due to the plant’s natural defense system, a process which starts with a molecule called taxiphyllin.
Taxiphyllin belongs to a class of compounds called cyanogenic glycosides, and are produced by a variety of plant species (and also by some butterflies). These compounds help the plant protect itself against predators. Cyanogenic glycosides are found, for example, in cassava, sorghum and, in lesser quantities, in almonds, stone fruit, and apples. The dose makes the poison! It is safe to eat raw apples, peaches and apricots (avoiding the seeds/pits, where most of the glycosides are concentrated), but sorghum, cassava and bamboo require processing before they are safe to eat.
The bamboo cutter wandering in the bamboo grove (Nishimura 2013)
Although cyanogenic glycosides are harmless in and of themselves, as soon as you start to break down the cell structure of the plant,whether by cutting, grinding, chewing or digesting the plant, they are joined by an enzyme called β‐glucosidase. Through a chemistry magic trick called hydrolysis, these enzymes degrade cyanogenic glycosides into the much more familiar and alarm bell-raising hydrogen cyanide. That is bad news, since cyanide is toxic to human bodies, and, in certain amounts, such as the ones found in certain bamboo shoots, can cause neurological symptoms and even death.
Fortunately, humans have devised many ways of eliminating cyanide from the plants that contain them, the most common and simple of which is by boiling them for a Very. Long. Time.
According the reports I skimmed through, the amount of cyanogenic glycosides found in bamboo shoots varies immensely, depending on the species of bamboo, the type of soil in which it they were grown, how old the shoots were when they were picked, and a multitude of other variables. A village in China may have been perfectly okay with boiling its shoots for 30 minutes, while a village in the next valley may have had much better results with a much longer cooking time, buffered by periods of soaking (which also reduces cyanide levels).
Fresh bamboo shoots on my countertop
Since I had no way of knowing what type of bamboo I had resting on my countertop, where it came from, or what kind of soil had nourished it during its short life, I decided be safe by choosing a boiling procedure that was slightly more aggressive than the other.
In Japan, when preparing bamboo shoots, it is customary to add powdered rice bran (nuka) and a few dried red peppers (taka no tsume) to the cooking water. Apparently, the starchy oils in the rice bran help absorb the toxins leaching out of the shoots, while the peppers help prevent rancidity and offset any additional bitterness (Andoh 2010) Although I have found no scientific evidence to support these claims, I tend to trust food-safety-related cultural practices as they have stood the test of time. In any case, these simple additions wouldn’t do any harm.
How to Prepare Fresh Bamboo Shoots
An Illustrated Guide
Cut the pointy end off at an angle.
Cut a slit through the thick outer layers of the concave side of the shoot.
Place bamboo shoots and chile peppers in the instant pot liner. Add 1 cup rice bran flour (nuka). Add enough water to cover the shoots, and cook on high pressure for 40 minutes. Let the shoots soak in the rice bran water until it has cooled down to room temperature.
After rinsing the cooked shoots, start peeling off the outer leaves.
Keep peeling. You’re almost there!
Cut the tough stem off (about 1-2 cm from the edge).
Trim off any remaining brown spots.
If you don’t use them immediately, cover them in water and store them in the fridge for up to 5 days, changing the water every day.
It found it amusing and oddly satisfying to peel the shoots. I watched with mild dismay as the pile of peels grew and grew, wondering if there would be anything left for me to eat at the (not to worry, there was plenty). The fresh shoots had a pleasant aroma reminiscent of artichokes (and not at all reminiscent of formaldehyde). Between my teeth, they had a crunchy and juicy texture, and a refreshing taste.
I declare fresh bamboo shoots and their canned counterparts to be two different specimens unrelated to each other, and between the fruit of the formaldehyde orchard, and that of the bamboo grove, I have little doubt of which I prefer.
So, back to my original question: who buys fresh bamboo shoots?
I do. And I’d buy them more often if only they were more available! Hooray for slow food.
Joëlle
Preparing your own bamboo shoots might be more time-consuming than buying a can at the supermarket, but the taste and texture of fresh bamboo shoots make the process more than worth it.
Ingredients
- 2-3 Fresh bamboo shoots
- 1/2 cup rice bran flour (nuka)
- 2 dried chile peppers (taka no tsume)
- Water (to cover the shoots)
Instructions
- Prepare the bamboo shoots: cut the pointy ends off at an angle (see picture). Cut a slit through the thick outer layers of the concave side of the shoot.
- Place bamboo shoots and chile peppers in the instant pot liner. Add 1 cup rice bran flour (nuka) and enough water to cover the shoots.
- Cook on high pressure for 40 minutes, and let the pressure release naturally. Leave the bamboo shoots to soak in the rice bran water until the water is cool to the touch (you can leave them to soak overnight)
- Discard the soaking water and the peppers and rinse the shoots well to remove the bran.
- Start peeling off the outer leaves, and keep going until you are left with only the tender, pale golden flesh .
- Cut the tough stem off (about 1-2 cm from the edge), and trim off any remaining brown spots.
- Fresh bamboo shoots are best consumed on the day they are cooked, but you can also store them in the fridge, submerged in water, for up to five days, if you change the water every day.
A happy Takenoko (Nishimura 2013)
References
Andoh, E., & Beisch, L. (2010). Kansha: Celebrating Japans vegan and vegetarian traditions. Berkeley: Ten Speed Press.
Bolarinwa, I. F., Oke, M. O., Olaniyan, S. A., & Ajala, A. S. (2016). A Review of Cyanogenic Glycosides in Edible Plants. Toxicology – New Aspects to This Scientific Conundrum. doi:10.5772/64886
Chongtham, N., Bisht, M. S., & Haorongbam, S. (2011). Nutritional Properties of Bamboo Shoots: Potential and Prospects for Utilization as a Health Food. Comprehensive Reviews in Food Science and Food Safety, 10(3), 153-168. doi:10.1111/j.1541-4337.2011.00147.x
Nishimura, Y. (Producer), & Takahata, I. (Director). (2013). Kaguya-hime no monogatari (かぐや姫の物語) [Motion picture]. Japan: Studio Ghibli.
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