Japan’s wasabi producers farm ‘green gold’

The knobbly root is difficult to grow, and is consequently an expensive buy for many

Izu: If you’ve eaten sushi, you might assume you’ve tried wasabi. But chances are it was an artificial version that Japanese growers say is a world away from their ‘green gold’. Unlike the spicy neon concoction familiar to many fans of Japanese cuisine — which is in fact made from horseradish — real wasabi is pale-green and offers a complex, mildly piquant flavour. But even in Japan, it’s not common fare. That’s because the knobbly root is so difficult to grow, and consequently expensive to buy, with most of it snapped up by wholesalers.

“The most important requirement is crystal-clear water, in abundance,” Yoshihiro Shioya, 62, said as he pulled a wasabi root from the sodden soil at his lush, green mountainside farm on Shizuoka province’s Izu peninsula. “It’s absolutely necessary that the water temperature stays between 10 and 15 degrees Celsius, year-round,” added Shioya, whose family has cultivated wasabi in the region for seven generations.

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Patience is key — each wasabi crop can take a whole year or even 18 months to mature in the large man-made terraces, which serve a particular design purpose. “The water flows down from the top of the mountain, which has terraces built into it covered with layers of pebbles and sand that filter and purify it,” explained Yasuaki Kohari, of Izu’s agricultural cooperative.

Once ready, the long roots, topped with a plume of round green leaves, are harvested by hand. The leaves are stripped off and the root, known as a rhizome, is carried away in baskets. About half of the 550 tonnes of fresh wasabi grown in Japan last year came from Shizuoka, southwest of the capital Tokyo.

Wasabi grows naturally there and has been used in local cuisine for centuries. Legend has it that it was especially loved and popularised by 17th century shogun Ieyasu Tokugawa, a military ruler who was one of the unifiers of Japan. These days it is mostly purchased by high-end restaurants in Tokyo and Osaka.