11. THE CAMPAIGN FOR REAL WASABI

It is rare to find Wasabia japonica served outside of Japan. I had only ever seen the Kermit-green, sinus-scorching paste, usually made from dyed horseradish served—quite incorrectly, it turns out—as a blob on the side of a sushi plate. But as I was about to discover, fresh wasabi root has about as much in common with that substance as snow from a spray can does with the real deal.

Lissen, Asger, and Emil had chosen to spend the day at KidZania, an indoor theme park where children take on proper jobs, such as fireman, dentist, or graphic designer, and earn fake money, which they can then exchange for chocolate and fizzy drinks: designed, I think, to prepare Japanese children for a life as diligent taxpayers.

Meanwhile, I traveled about sixty miles south of Tokyo to the Mount Amagi area on the Izu Peninsula, in Shizuoka, a forested area south of Mount Fuji. This is a popular onsen—or hot spring—area, but for the Japanese, it is also synonymous with wasabi: over 60 percent of Japanese wasabi is grown here—worth ¥2.5 billion ($22 million) a year.

I hired a car for the final drive up into the hills. My first stop was for a meeting with Yoshio Ando, head of the local wasabi growers’ association, in the small shop and wasabi processing center he runs with his wife. Yoshio, in his late fifties and sporting an oversize baseball cap with a cartoon wasabi character on it, explained that he was one of 355 wasabi growers in the region.

Wasabi is one of the most temperamental plants in the world, he said, requiring precise climactic conditions and fresh water, lots of it. “Wasabi needs very clean, fresh-flowing water to grow,” Yoshio explained. “The water is the key; it needs to be around 53°F to 55°F [never more than 60°F, never less than 50°F] and flow at 4.7 gallons per second to keep a constant depth of half an inch. We have wonderful mountain springwater here, but the climate is also crucial. You need a cool summer and water throughout the year.”

He offered me a real wasabi root to inspect. “This one will sell for more than ¥3,000 [$25] in Tokyo,” he said. “It is only for the rich. It is very limited quantity.” Although we had passed several giant fiberglass replicas on the roads (the Japanese are fond of promoting their local specialties in oversize roadside model form), I had never seen a whole wasabi root before. It was knobby, green, and rather phallic, with floppy leaves at the top end, tapering to a point at the other. This one was roughly the size of a banana. The roots can grow larger, but the ones you see in Japanese supermarkets tend to be more Mars bar–sized. “They are harvested throughout the year when the plant has reached between fifteen months and two years, during which time it grows progressively hotter in flavor,” Yoshio told me.

The Japanese have been cultivating this enigmatic plant—a rhizome and distant relative of the horseradish—since 1744. It was originally used as a sterilant to kill bacteria on fish, among other things, which is how it came to be associated with sushi and sashimi. It is also believed to stimulate the appetite.

I asked about the difference between fresh wasabi and the wasabi you buy in tubes. Yoshio shook his head dismissively. You couldn’t compare them, he said. Good, fresh wasabi is hot, but not burning hot, and much sweeter, more fragrant than the industrial stuff. And, needless to say, Japanese is best.

They do grow wasabi in Taiwan and China, but when I asked about this, Yoshio shook his head even more vigorously. “They grow in soil in Taiwan. No running water, lots of chemicals. The same in China.” But surely there must be other places in the world with similar water supplies and climate, and with a crop as desirable as wasabi, others must have tried to cultivate it the correct way. “Yes, I have heard they grow it in Canada and New Zealand. Maybe that’s better.” But the look on his face suggested he thought otherwise.

I was finding it difficult to visualize how wasabi grew. Was there any chance Yoshio could show me? He looked dubious and conferred with his wife in a low murmur for a while. They didn’t usually do this, he said finally, and he did like to keep his fields secret for obvious reasons—implying, intriguingly, the existence of wasabi rustlers—but seeing as I had come all this way, he agreed to take me to see his fields, higher up the mountain.

I followed his raggedy Toyota pickup for over an hour up into the forests of pine, cedar, and bamboo, far from the tourist onsen towns. It was thrilling to imagine that, somewhere in the trees around us, wild wasabi—as opposed to Yoshio’s cultivated variety—was growing in fresh flowing streams.

We came to a deep, dark, forested river valley, open at one end with a spectacular view to the landscape below, narrowing at the other end, where the river that gives life to the wasabi descended from the summit. As I followed Yoshio along a narrow, overgrown path to the wasabi paddies, dragonflies and butterflies bright as Hermès scarves flapped up from the undergrowth. Lizards scattered every which way, and bright green spiders hung from webs in the trees. I had a sense of being shown something secret and precious, for here Yoshio grows what is not just the best wasabi in Japan (and therefore the world—he’s won every prize going), but, according to a recent prime-ministerial pronouncement, one of the best items of produce in the country.

The entire valley floor had been terraced rather like a rice paddy, but instead of the bright green, grasslike rice plants, it was carpeted with the broad, rhubarb-like leaves of wasabi. The sound of running water was deafening, although there was no river in sight. It was all flowing beneath the plants, which were packed, Yoshio told me, in a six-inch-deep bed of sand. The plants themselves were covered with black netting to keep them from sunlight and falling leaves. “The angle of the slope is very precise; otherwise, the water would flow too fast. The other problem we have is with the local deer. They love the leaves,” Yoshio said. I tasted one. It was a little like arugula, but with a sweet, burning wasabi aftertaste.

I asked if he had any tips on using wasabi. “Ooh, you’ve got to try the stems pickled in sake lees; that’s lovely.” When I left Japan, I was planning to take some roots home with me. How long would one keep? “Keep it dry and it will last a month, but if it gets damp, it will turn black.”

“You know,” Yoshio said later, after our hour-long tour of the wasabi fields and as we were about to leave, “if you really like wasabi, there is someone you should meet.”

Shirakabeso, or the “white wall inn,” was back down in the onsen region of Shizuoka. It is a traditional onsen guesthouse with two communal outdoor baths run by a husband-and-wife team, Haruyoshi and Ikuko Uda. Ikuko, Yoshio’s contact, is obsessed with wasabi and has spent years studying it at the University of Shizuoka under Professor Naohide Kinai, a specialist in the various medicinal properties of this miraculous root.

As we sat on the floor in a simple room with a tatami-covered floor in the traditional manner, overlooking an immaculate garden, Ikuko explained the basic principles of using wasabi. “You grate it on sharkskin,” she said, “because that is fine and gentle but tough. And you must grate it in a circular motion. When the oxygen mixes with the wasabi, it increases its hotness. The top end is sweeter than the bottom end.” She showed me how to do this, making gentle circles with the root on the sharkskin board.

She could see I was looking a little anxious about consuming the entire wasabi root—it was a large one. “Don’t worry. Real wasabi warms the throat; it doesn’t burn or go up your nose like the artificial stuff. And you know what? If you eat wasabi and drink, you don’t get a hangover, because it is antibacterial and detoxifying.”

As well as various minerals and vitamins, wasabi contains around twenty different types of isothiocyanates (compounds it shares with mustard and broccoli), which have anti-inflammatory properties. This makes wasabi a useful treatment for allergies and eczema. Its antimicrobial qualities also mean it works against tooth decay, and apparently, it can even calm diarrhea. Most interesting of all, the isothiocyanates are thought to stop the spread of cancers at the metastasis stage. Wasabi is, then, a bona fide superfood.

The real thing did indeed taste very different from the paste. The isothiocyanates give wasabi a pleasing pungency when grated, and as they evaporate, they release a brief, pleasurable sinus heat. Sometimes chefs will add a little sugar to real wasabi to enliven the pepper flavor.

Ikuko began to present the dishes we would be eating that afternoon: pickled rhododendron, chrysanthemum, and jellyfish (surprisingly crunchy) to start. I noticed a beautiful abalone shell on the table and turned it over; inside, the creature was still writhing. Ikuko placed it on the hot plate for a minute or so and served it sliced with a small mound of wasabi as accompaniment. It was sublimely tender. As well as wasabi, this region is famed for its wild boar, which I had a chance to taste next. It had been marinated and tenderized in miso and koji (the fermenting agent added to sake) for ten days, which helped make the flesh spoon-tender. Its deep, gamy richness went superbly with the sweetness of the wasabi, again neatly placed in a small mound on the plate.

I asked Ikuko how she grew to be so obsessed by wasabi. “I started seven years ago. I wanted to make the most of our local produce and surprise people.” She had certainly done that, although, in doing so, she had probably ruined my enjoyment of wasabi paste and sushi forever. How could I ever go back to artificial wasabi? By the end of the afternoon, I had consumed half an entire wasabi root by myself, with no ill effects. In fact, it had been a stunning and surprisingly delicate meal. It finished with the juiciest, sweetest melon I had ever eaten, together with wasabi ice cream, of course.