Ideal wasabi-growing environment: Horticulturalist Stephen Welsh at his Tasmanian farm.
If you really want to get on the wrong side of Stephen Welsh tell him that you cannot tell the difference between wasabi and horseradish.
"Oh, it's a completely different taste experience," he says. "Fresh wasabi has an intense, sweetish and more rounded flavour.
From Tasmania's north-west coast to markets in Malaysia, Hong Kong, Singapore and Taiwan.
"Think of horseradish as being a thump on the back. Eating wasabi is like getting a gentle hug from an old friend."
Fresh wasabi tastes distinctly different from horseradish.
The slightly messianic tone is understandable. Much of the wasabi paste found in supermarkets is actually made from horseradish – and while the two belong to the same family, Wasabia japonica is an extremely delicate and unusual plant.
"Wasabi is one of the most difficult crops to grow in the world, which is why there's hardly anyone outside Japan growing it successfully," explains Welsh, 44, a trained horticulturalist.
"It needs very cold conditions, as well as low light level and is very sensitive about water quality."
Wasabi is challenging to grow.
In its native Japan, wasabi is grown in riverbeds. Over the past 12 years Welsh and his wife Karen have transformed their Port Sorrel farm, on Tasmania's north-west coast, into the ideal wasabi-growing environment, building a shade house and hydroponic system – although several early crops failed or produced unusable stems.
"Because it's such a challenging thing and a slow growing crop, so many people who have tried it have just given up in frustration," he says.
Today, Shima Wasabi is Australia's only commercial wasabi producer, exporting its freeze-dried wasabi and other wasabi products to food manufacturers in Hong Kong, Singapore, Taiwan and Malaysia.
"We pretty much sell out of our wasabi spices as soon as we can produce it – and most of that goes overseas," Welsh says.
The bulk of Shima Wasabi's fresh product is snapped up by Australia's top chefs, such as Tetsuya Wakuda, who use the aromatic stems but are also buying the plant's leaves and flowers; only the wasabi roots are inedible.
Apart from the restaurant trade, artisan food producers have also fallen in love with Tasmanian wasabi which now flavours everything from mustard to cheese and is used to infuse black cherries in syrup. Several craft breweries are experimenting with wasabi flavoured beer.
With just half a hectare of land under wasabi cultivation, the biggest challenge facing Stephen and Karen Welsh is keeping up with the growing demand from chefs, Asian snack food companies and experimental home cooks.
"We desperately need to expand our growing capacity," he says. "With the right investment I'm convinced that wasabi could become a $15 million [a year] industry for Tasmania."
The Shima rollcall
Tetsuya's and Quay - Sydney
Garagistes - Hobart
Lake House Restaurant – Daylesford
Nobu - Melbourne
Char Restaurant - Darwin
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