Wasabi is not simply American horseradish with a kick of hot mustard and some green food coloring. Not very long ago, real wasabi—a short green plant with an edible stem, or rhizome—was grown only in Japan and primarily in cold mountain streams. What’s more, the rhizome spoils in a week, and freshly grated wasabi loses its punch after 15 minutes on the plate. Faking it was easier and cheaper than trying to find the real thing.

But in 1991, entrepreneur Roy Carver III decided that the Oregon coast was perfect for growing wasabi. His hydroponic technique broke the Japanese lock on the market. He caused a little competitive intrigue, too. “Some people came on the property uninvited,” recalls Ted Wakeman, production manager at Carver’s Pacific Farms. “We escorted them off. They never could figure out how we [could grow wasabi].”

The wasabi growing process has now also been cracked in New Zealand, Canada, China, and Taiwan, often using soil instead of running water (connoisseurs swear they can taste the dirt).

What’s the big deal with real? For one thing, faux wasabi is all bluster. “Fresh real wasabi is sweet, crisp, and vegetal at the front of the tongue and hot at the back,” according to Wakeman, “letting you enjoy the flavors before the heat hits; then it dissipates so you can enjoy another bite.”

Real wasabi may have some health benefits, too. When the cells of the plant are torn apart by shredding, the resultant paste contains chemicals that may inhibit blood clots, asthma, and inflammation. Its antibiotic properties are one of the reasons it’s always served with raw fish.

But don’t fall for wasabi powders, even those made from real wasabi. Drying wasabi causes it to lose its pungency. “Manufacturers put it in foods just so they can call them wasabi, but the flavor is gone.” They use horseradish for flavor.

Japanese-grown rhizomes are sold at gourmet stores in California for $100 per pound. Fresh roots of soil-grown wasabi can be ordered from Canada’s Pacific Coast Wasabi (www.wasabia.ca). Pacific Farms, meanwhile, sells frozen wasabi paste, which will last for 30 days in the fridge (www.freshwasabi.com).

Photograph by Kevin Twomey