I hate to break it to you, but it’s likely that you’ve never actually even tasted real wasabi before. That little bright green dab next to the pickled ginger on your plate, the one you’ve been swirling into your soy sauce? Chances are that you’ve been eating horseradish, masquerading as wasabi for your entire sushi-eating life. The only question is, why has the Wasabi Industrial Complex been pulling the wool over our eyes for so long? To answer that, we need to first understand what the two foods actually are.
Wasabi is a member of the Brassicaceae family, which also includes various cabbages, mustard, broccoli and, yes, horseradish. But that doesn’t mean the two are entirely similar. Wasabi may sometimes be called Japanese Horseradish, but they are actually two completely different parts of different types of plants.
Wasabi is a rhizome, a continuously-growing underground stem that expands horizontally. Both upward-pointing stalks and thick, downward-pointing roots expand vertically from the stem at random intervals. Wasabi, when carefully excavated from the earth in its entirety, looks a bit like a haunted, ancient root. When it is sold fresh though, it is broken down into more manageable bits. Horseradish, on the other hand, is a root vegetable, white in color beneath the earth, with green stalks growing upwards. Got that? Wasabi stems are its gem, while horseradish roots are what people are after.
Both plants pack a zesty punch, strong enough to clear out even the most congested of sinuses, though wasabi is perhaps the more elegant of the two. Beyond the initial sensation, the tastes differ pretty strongly. Horseradish is all heat and nose, whereas wasabi has delicate vegetable and floral notes that are fairly easy to hone in on.
Food Culture: You've probably been eating fake cinnamon your whole life
Both plants were traditionally cultivated more for their medicinal properties than for their usefulness in cooking. Wasabi has natural anti-inflammatory and, most importantly, antimicrobial properties. It’s this inherent ability of wasabi to prevent the growth of microorganisms that caused ancient peoples to pair it with fish. Wasabi is also rich in Vitamin C, calcium and potassium, and possesses a type of compound called isothiocyanates that help alleviate the symptoms of allergies, asthma and maybe even prevent tooth decay.
Horseradish is no shrinking violet either, packing a considerable bounty of healthy properties as well. The root is rich in the same Vitamin C, calcium and potassium in wasabi, along with manganese, magnesium and zinc. Horseradish can also help regulate the passage of nutrients between cells, relieve digestive issues like constipation and diarrhea, and help alleviate the symptoms of urinary tract infections. So while horseradish isn’t necessarily wasabi, at least the replacement condiment isn’t nutritionally devoid of value.
Food Culture: Pumpkin spice is a big fat lie
But even if horseradish were nutritionally superior to wasabi, the question remains: what’s with all the secret moonlighting? Why is horseradish being processed, sold, and consumed under wasabi’s identity? Two answers may help explain.
For starters, real wasabi is incredibly difficult to farm. It’s sensitive to both sunlight and warm temperatures, and left to its own devices, grows only in well-shaded mountain stream beds in limited parts of Japan. Growers have been able to recreate those conditions in parts of the U.S., Taiwan and China, but farms are limited to thin bands of land where temperatures stay roughly between 45 and 70 degrees Fahrenheit. For these reasons, wasabi is called the world’s hardest plant to grow.
And if that weren’t enough of a reason to limit the availability of true wasabi, get this: wasabi loses its trademark punchy flavor in as little as 15 minutes after it’s exposed to air. A notoriously difficult to grow plant whose flavor rapidly depletes when it simply touches the air around it? All of that adds up to a scenario in which as few as 5% of the world’s sushi restaurants outside of Japan actually serve the true blue plant. So if it’s real deal wasabi that you’re after, you might want to book a flight to Tokyo.
