Known as the ‘King of Herbs’ the wasabi plant is notoriously difficult to grow. So difficult in fact that you’re unlikely to have ever tasted the real thing. That blob of green mush, served on the side of your plate at a sushi restaurant is actually horseradish coloured with green food colouring.
Real wasabi is much stronger and has a complex flavour profile. It is highly prised and sells for about €280 a kilo. It is usually cultivated using stream water in mountainous regions of Japan, however now a chemist has managed to grow it for the first time on the island of Ireland.
Sean Kitson, is a radiochemist by day, living in Tandagree, Armagh, Northern Ireland, is, after much research and a lot of experimentation, harvesting his wasabi rhizomes and sending them far and wide to new customers.
It was a risk for Kitson, to put his time and money into a project that could so easily fail but, as a chemist he was attracted to the challenge of growing such a difficult plant. Were it not for Sean’s science background he doubts he would be harvesting the rhizomes today.
“You can’t have too much light, so we grow it in an 80% reduction of light, so it’s a bit like growing mushrooms. You have to take care of the water’s pH… it’s just a really difficult plant to grow. If I didn’t have a scientific background I wouldn’t have been able to grow them.”
It wasn’t just the plant’s inherent difficulty to grow that attracted him to it, his son was the one initially who piqued his interest in wasabi.
“It was my son’s idea. He was about 14 at the time and he wanted to start a business growing rare garden plants but the energy in the greenhouse of 30 degrees, would have been quite expensive. So I told him to go away and find another idea so he went and researched wasabi, which I found very interesting from a chemistry point of view because it’s a medicinal plant. It tied in quite nicely with my chemistry background,” says Sean.
Zak was drawn to the wasabi plant because of its medicinal properties. Having been diagnosed at a young age with Multiple Sclerosis (MS), he is aware of the power of plants and food in our diets and their ability to contribute to the management of certain conditions.
“When my son was five years old, he collapsed in the supermarket, so we took him to the hospital and two years later, after many tests and consultations he was formally diagnosed with Multiple Sclerosis.
“Wasabi is a medicinal plant, the reason it’s used in Japan, on raw fish, is because it has antibacterial properties. It also has anti-inflammatory and recent research suggests, anti-cancer properties.,” says Sean.
Wasabi appears in the Honzo-wamyo (Japanese Names of Living Things), a collection of 18 volumes of 1,025 types of plants including animals and minerals. This encyclopedia was written in the year 918 by Fukane Sukehito in the Heian period (794-1185) and describes wasabi as a medicinal plant which at the time was known as wild ginger. Wasabi cultivation in Japan has continued for over a thousand years.
During the Keicho period (1596-1615), the majority of wasabi cultivation was carried out on the Abe River in Shizuoka prefecture in central Japan. During this time wasabi was entirely consumed by the Japanese upper class. It is the Shimane prefecture that produces the most wasabi rhizomes. It is grown outside Japan in New Zealand, Iceland, Taiwan, Korea, Israel, Brazil, Thailand, Columbia, Canada, USA, England and now, Northern Ireland.
The pungent taste of wasabi is the result of volatile naturally occurring organosulphur compounds called isothiocyanates (ITCs). These volatile ITCs are released when the plant tissues undergo mechanical damage resulting from cutting, grating and mastication.
“The active ingredient in wasabi is allyl isothiocyanate, that’s what gives it its kick,” explains Kitson.
“Once the rhizome is grated, the enzymes release the allyl isothiocyanate which is volatile. You usually have to consume it within 20 minutes. You can reactivate the enzyme though with some lemon juice.”
There has been a great interest in Sean’s wasabi crop. His cultivation method means he can supply not only high-end restaurants but individuals too. One customer in Holland offered to take the entire crop from him but Sean declined. It doesn’t make good business sense to offload the entire harvest in one go. Kitson is looking to build a clientele so he is sticking to selling his wasabi to restaurants and individuals online from his site wasabicrop.com and from Amazon.
“I dig the rhizomes up and I cut the head off, so when you get 100 gr of rhizome from me, you get 100gr. I trim both ends off, I vacuum pack it, which stops oxidation and keeps it fresh. Then I freeze it. If you order it, I send it and it thaws in transit and when you receive it, you remove it from the vacuum pack, wash it, and wrap it in the cheesecloth I supply with it. You put it in an open jar and keep it moist every two or three days. Consume it within 10 days.
Kitson says his wasabi tastes fantastic and he’s not the only one. Kitson brought his wasabi to a Japanese restaurant in Belfast and gave it to the chef to try. He agrees with Kitson wholeheartedly saying it’s the best he has ever tasted.