The Spice: Wasabi

Originally published on "Tokyo Winter/Spring2022 (Jan., 2022)"
True fresh wasabi in sushi can pack a punch that literally throws your head back, and it grows in the clear mountain streams of Okutama in western Tokyo.

One of Japan's iconic foods, sushi is known around the world, but many people visiting Japan express surprise when they try fresh wasabi here. That is because most wasabi sold abroad is simply Western horseradish colored green. Fresh wasabi grated immediately before enjoying a seafood meal can be an eye-opening, and eye-watering, experience. Part of the Brassicaceae family, which includes broccoli, kale, cabbage, radish, and turnip, wasabi can pack a mighty mustardy punch.

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Few would suspect that a cool peaceful stream in an idyllic scene like this would make the perfect conditions to grow a spicy plant like wasabi.

Those wishing to search out wasabi in situ need look no further than Okutama, a mountainous region in western Tokyo. A two-hour journey from the center of the metropolis by train or car, its lush, picturesque scenery is a far cry from the city skyscrapers, and its cooler climes are beloved by hikers. Wandering through the forests, one may come across inclined terraces buttressed by rocks with streams of cool spring water running through them. Carefully tended by local farmers, the paddies are studded with green, broad-leafed plants. These are wasabi plants, an essential condiment when eating sushi.

Standing by a wasabi terrace just outside the town of Okutama, Hoshina Masahiro, head of the Okutama Wasabi Cultivation Society, points to the leafy stems of the wasabi, their knobby rhizomes irrigated by a steady stream of pure clean mountain water. Clean flowing water is essential for wasabi cultivation, and this beautiful area of Tokyo provides that in abundance. Okutama's climate and environment supports many wasabi terraces where the crops are planted in spring and harvested in autumn of the following year.

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Proceed with caution. This unassuming rhizome packs a strong spicy punch.

"The difference in temperature between Oku­tama's cold winters and hot summers is the crucial element that makes wasabi spicy," says Hoshina, who, rather than smearing on sashimi, recommends grating the vegetable and mixing it with soy sauce and bonito flakes to use as a dip. "One characteristic of the wasabi of Okutama is that they are firm and spicy."

Wasabi farmers must tend to their terraces often, protecting their crop against weeds and animals such as deer and boar. Hoshina is one of 57 members of the local wasabi farmers' union, whose ranks once numbered in the hundreds. The lack of successors is a problem for many Japanese farmers, but the demand for wasabi is always strong. The Okutama region still boasts over 100 wasabi paddies, and specialty shops such as Yamashiroya--just five minutes' walk from Okutama Station--do a healthy trade.

Yamashiroya began wasabi farming in the Edo period (1603-1868) and started selling wasabi products around 100 years ago. Aside from fresh wasabi, Yamashiroya sells a variety of wasabi products reflecting both a sense of innovation and a deeply felt love for the piquant root; their main focus being wasabi-zuke (pickled wasabi paste).

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Four types of the popular wasabi-zuke at Yamashiroya. There are also versions made with seaweed or herring roe.

Wasabi-zuke is made by cutting up wasabi leaves and stems, seasoning them and pickling the mixture in matured sake lees (a paste byproduct of sake production). "Here at Yamashiroya, we use sake lees from locally produced sake and mature it at a low temperature for over a year," says Kaneko Yukihiro, senior managing director of Yamashiroya. "This gives it a smooth flavor, as well as bringing out the umami of the lees and allowing it to retain its characteristic whiteness. The wasabi and seasoning are then added and left to pickle for two-to-three days, and then it is ready to eat."

Yamashiroya's product inventory includes wasabi-zuke mixed with nori seaweed or miso paste, as well as various snacks that pair perfectly with a glass of beer such as wasabi cheese and smoke-flavored wasabi-zuke. One can also buy wasabi senbei rice crackers, and wasabi gelée dressing. "As for the best way to enjoy wasabi-zuke, I recommend having it with hot steamed rice and a kamaboko fish paste cake: even a cheap one will do nicely."

More information about the diverse agricultural, forest, and fishery products Tokyo has to offer can be found on the TOKYO GROWN website. The site, for both domestic and overseas visitors, features timely information in reports from producers about the fresh and safe agriculture, forestry, and fisheries produce generated in Tokyo.

Of course, not all of Japan's wasabi comes from Okutama; however, the rich nature, misty mountains, and cool clear streams in this most beautiful corner of Tokyo can be called to mind if you try a smear of freshly grated wasabi next time you have sushi.

By Tim Hornyak