On a farm in Hampshire in the south of Britain, pungent wasabi plants that can be ground up to provide an essential condiment to accompany traditional Japanese dishes like sushi are flourishing.

Starting with 400 wasabi plants 13 years ago, the Wasabi Company, founded by CEO Jon Old, now harvests roughly 1.5 tons per year after much trial and error throughout the cultivation process.

Helped by the growing popularity of Japanese cuisine in Britain and the image of it as healthy, the company not only sells wasabi to several Japanese restaurants in London and beyond but also to Michelin-starred British chefs such as Gordon Ramsay and the 5-star Dorchester Hotel near Hyde Park.

Undated photo shows freshly grated wasabi from the Wasabi Company's farm in Hampshire, south of Britain. (Photo by Setsuo Kato)(Kyodo)

The freshness of its newly harvested produce has helped the Wasabi Company establish a considerable reputation, with its exports now going to seven European countries.

Step onto the company's farm near the village of Micheldever, and you will find the lush dark green wasabi leaves spread out all around under protective black netting.

Groundwater pumped from 40 meters below flows like a stream underfoot, and thick gravel of different shapes and sizes replicates an environment much like the natural streams where wasabi, known by the scientific name eutrema japonicum, grows in Japan.

While it has been challenging to replicate the perfect environment for wasabi to grow, the fact that the company uses former watercress farms has worked wonders given the similar conditions in which both plants thrive. A former watercress farmer, it was this knowledge that inspired Old to become the first commercial grower of wasabi in Britain.

In 2010, one of Old's regular watercress customers, a South African chef, approached him about the possibility of growing wasabi, and the rest is history.

John Old speaks in an online interview in June 2023. (Kyodo)

Old now runs three different wasabi farms in the south of England with his son, Guthrie, 20, who helped him until late August. But before 2010, Old had only heard of wasabi as an ingredient for sushi.

When he discovered that it grew in the same conditions as watercress -- which demands moving water to provide a steady supply of fresh minerals -- he decided it was something he might be able to do.

Although he obtained his first batch of 20,000 wasabi plants from a farmer in Japan's Yamanashi Prefecture, his initial attempts at cultivation on his Dorset farm ended with half the crop dying due to the English county's climate.

But a trip to Japan's Shizuoka Prefecture -- initially met with some hesitation from growers of the plant -- to learn from experienced wasabi farmers proved invaluable.

Armed with new expertise, Old returned to Britain and began to apply it to his own wasabi plants, typically harvested after 18 months to 2 years, when the rhizomes grow to around 2-3 centimeters thick and 10 cm long.

Although Old first marketed his wasabi to restaurants in 2012, he encountered resistance from chefs who were skeptical of wasabi grown in Britain. Japanese restaurants also tended to opt for Japanese imported produce, meaning that few were willing to take a chance on the fledging Wasabi Company.

It was only after he personally invited these chefs to his wasabi farms to see how it was being grown and to taste some freshly picked samples for themselves that he gained a reputation for quality.

When demonstrating the quality of their produce to visitors, either Old or Guthrie often take a freshly harvested wasabi rhizome and scrape the outer layer with a knife, releasing its pungent aroma, Guthrie said in an interview in June. He added when visitors taste it, they experience an immediate burst of spiciness followed by a subtle hint of sweetness.

"The most interesting thing I find about wasabi is that if you tasted it right after grating, it wouldn't have much flavor," Guthrie said. "But after five minutes, all the heat will come out -- and then after 15-20 minutes, it will lose its flavor again."

Guthrie checks the growth of wasabi on the Wasabi Company's farm in Hampshire, south of Britain, in June 2023. (Kyodo)

Now firmly established, the Wasabi Company not only enjoys the high regard of chefs across Britain but also supplies Japanese and Western restaurants in the Netherlands, France and Sweden, among other countries.

For Guthrie, who joined his father in the business two years ago, working his way up through the Wasabi Company's ranks was a welcome challenge, allowing him to learn about a unique business.

"I started pretty much packing boxes for a year and then slowly worked my way up," Guthrie said. "It's been great just learning about something new and challenging myself. But growing wasabi in the U.K. was always going to be the perfect challenge."

Alongside wholesale wasabi, the company also has a wide range of products for individual purchase on its website, from wasabi vodka and mayonnaise to "Grow Your Own Wasabi Kits." The wasabi rhizomes are priced at 10 pounds ($13) per 50 grams.

"More than anything, I'm really grateful to Japan for giving us these wonderful ingredients, which have also opened up the European market," Old said.

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