Dr. Universe explains wasabi

Ask Dr. Universe is a science-education column from Washington State University.

  • Thursday, November 8, 2018 12:44pm
  • Life
Illustrations by Rob McClurkan

Illustrations by Rob McClurkan

Dr. Universe: How is wasabi made and where does it come from? – Christian, 12

Dear Christian,

When you think of wasabi, you might think of that hot green paste people serve up with sushi. Some restaurants put a bit of wasabi on your plate, but it’s usually not real wasabi. It’s actually a mixture of horseradish, mustard, and green dye. Real wasabi is a lot different.

That’s what I found out from my friend Thomas Lumpkin, a plant scientist who studied wasabi as a researcher at Washington State University. Wasabi is a plant that mainly grows in Japan in the cool, running water of mountain streams and springs.

The part of the wasabi plant we eat comes from the stem, or the rhizome, which can be up to about 4 inches wide and 12 inches long. The plant comes in different shades of green, leaf sizes, and shapes, and in more than 20 different varieties.

Wasabi is one of the hardest plants to grow, which also makes it pretty valuable. If you wanted to buy real wasabi at a store, it would probably be about $95 a pound, Lumpkin said.

In nature, wasabi requires just the right environment to grow. It needs a cool climate, but not too cool in the winter. It also needs freshwater all year long and grows best in a bed of gravel. The Pacific Northwest can provide a lot of these conditions, along with some good shade. Lumpkin and some of his students actually helped people in the Northwest learn how to grow wasabi.

Now there are wasabi farms up and running on the coast of Oregon and Canada’s Vancouver Island. Growing wasabi takes a lot of patience. Only a few farms in the U.S. grow wasabi and only a few fine-dining sushi restaurants serve it.

When cooks prepare the wasabi, they shave off a bit of the stem to clean it up. They sometimes use very fine grating tools, called orsoshigane, which are used in Japanese cooking. These tools can grate up stuff a lot finer than the kind of cheese graters we usually find in the kitchen. Finally, they gather these tiny pieces of wasabi stem together. We might eat it with sushi, sashimi, or noodles. The leaves and the part that connects the leaf to the stem, called petioles, can be pickled or dried.

When we grate the wasabi stem, it breaks the plant’s cells and triggers a chemical reaction that gives the vegetable a very powerful flavor. It’s so strong that sometimes vapors will travel into the back of your mouth and up into the nasal cavity. It hits the sinuses and can easily make your eyes water.

Even though we might not be eating real wasabi when we go to a restaurant, the horseradish in the paste can still add extra spice to your meal. And now you know that wasabi is made by grinding up the root of a pretty interesting plant. It probably came from Japan—but there’s also a chance it was grown in the Pacific Northwest.

Sincerely,

Dr. Universe

More in Life

Registering to vote online or in-mail ends Monday

In-person registration is available up until Election Day, Aug. 6.

Cruz the Loop and Return to Renton Benefit Car Show set for July 6, 7

Hot Rod weekend, downtown, will have some street closures.

Join author Kurt Armbruster for a discussion of his latest book, “Pacific Coast, Seattle’s Own Railroad” at 6 p.m. May 16 at the Renton History Museum, 235 Mill Ave. S. Courtesy photo
Upcoming events: Pacific Coast Railroad history lesson; coffee with Renton cops

Symphony: Bellevue Youth Symphony Orchestra Spring Masterworks Concert will highlight Tchaikovsky’s Symphony… Continue reading

Renton Rotary’s Youth of the Month for May

Five Renton students were selected as May 2019 Youth of the Month to finish off the school year.

Gardeners love our veggie-friendly Western Washington climate

Here are the most incredible edibles to grow now.

A look back at Black River

Renton History Museum hosts event with Seattle writer and natural history expert David Williams.

It is a busy time in the garden with planting

Near the end of April the nurseries will be overflowing with color.… Continue reading

Thom Cantrell, one of the organizers of the upcoming International Conference for Primal People, holds up a mould of a Sasquatch footprint. He said the mould was taken in the Blue Mountains in Oregon by Paul Freeman, a well-known Sasquatch hunter who’s 1994 footage of a Sasquatch in that area made big waves in the believer and skeptic communities alike. Photo by Ray Miller-Still
All things Sasquatch in Enumclaw

Washington state is famous for countless reasons. It’s the birthplace of Starbucks… Continue reading

RHS Students gear up for Bubblin Brown Sugar dance competition

The competition is April 27 at Garfield High School.

Special police partners honored

King County Sheriff’s Office dedicates new memorial to honor K9 service dogs and handlers.