Cooking with Wasabi

Wasabi: It’s spicy and it flavors sushi. That’s all that most of us know about this green vegetable. It is also possible that you have never actually eaten real wasabi. I don’t think I have, even though I’m fond of sushi and have eaten at countless Japanese restaurants. That’s because wasabi is notoriously difficult to grow and requires a very specific type of climate. Western wasabi – and much of the wasabi eaten in Japan, for that matter – is actually horseradish mixed with a little mustard and food coloring.

True wasabi is a low-growing plant that grows wild in streambeds in the mountainous regions of Japan. When the leaves of the wasabi plant are trimmed off a root-like stem remains. This stem is ground (traditionally against a piece of dried sharkskin), creating a smooth paste. This paste must be eaten fast, because wasabi looses its spicy and grassy flavor quickly.

There are only a handful of farms growing wasabi in North America, located in the Pacific Northwest and the Blue Ridge Mountains of western North Carolina. Wasabi seedlings are fickle, and the plants take years to reach maturity. Whole fresh wasabi doesn’t have much of a shelf life (it must be shipped on ice), and grated wasabi has even less.

These factors make true wasabi very expensive. And since western palates are so accustomed to western wasabi (true wasabi wasn’t grown in North America until the mid-1990s), restaurants have little incentive to offer the real thing.

Thus, for the rest of this post, when I write about wasabi, I’m talking about the stuff that comes either powdered or in a tube. Even though the packaging might have Japanese characters on it, the first ingredient almost certainly will be “horseradish.”

Just because the wasabi we eat isn’t authentic doesn’t mean it can’t be a great cooking ingredient. There are lots of fantastic recipes with wasabi. I also wanted to learn more about the different types of wasabi that are available to the American consumer. I tasted powdered wasabi, tube wasabi, and I tried making my own fresh wasabi.

All western wasabis are some combination of horseradish and mustard. Some also include turmeric. To make my fresh wasabi, I used a very fine grater to grate 1 tablespoon of horseradish and 1 teaspoon of turmeric. I mixed this with 1/2 teaspoon of powdered mustard. I added one drop of green food coloring to make it the requisite green color.

Clockwise from top: Homemade fresh wasabi, squeeze-tube wasabi and reconstituted powdered wasabi.

There was no preparation necessary for the squeeze-tube wasabi. To reconstitute the powdered wasabi, I mixed equal parts wasabi and water and let the mixture sit for a couple of minutes. I did a quick taste test, sampling each wasabi plain. The fresh wasabi was milder than the other two options. The squeeze-tube wasabi had salt added, and it was much too salty for my taste. My favorite of the three was the powdered wasabi, despite its off-putting grey-green color.

Eaten straight, wasabi is spicy enough to make your eyes water. Mixed in to other foods, however, and it mellows considerably, providing a pleasant background kick. Here are three simple recipes to take wasabi beyond sushi.

Wasabi Mayonnaise: Combine 1 teaspoon prepared wasabi with 1/4 cup mayonnaise. Use on sandwiches, or make wasabi deviled eggs.

Wasabi-Glazed Salmon: Combine 2 teaspoons prepared wasabi, 2 tablespoons soy sauce, 2 tablespoons maple sugar and 2 minced garlic cloves. Smear over 1-plus pound of salmon and marinate for 30 minutes. Set oven to 350ºF and bake salmon until it flakes, about 20 minutes.

Wasabi Mashed Potatoes: Boil 3 pounds Yukon gold potatoes. Leave skins on and mash together with 1 stick of melted butter, 1 cup of Greek yogurt and 1 tablespoon of prepared wasabi. Salt to taste. (Note: I really love this recipe. Thanks to the Greek yogurt, it isn’t as calorie-heavy as other mashed potato recipes, but the butter gives it the right mouth feel. The wasabi isn’t overpowering.)