Using Wasabi in Cooking
True wasabi is a species of horseradish (Wasabia japonica) indigenous to Japan that grows in the loose, gravelly soil of mountain streams. It is also cultivated by a handful of growers in other parts of Asia and in North America. The spicy, nasal-clearing rhizome is most commonly used as a condiment for sushi and sashimi, but is also added to recipes when a fiery kick is desired. Because wasabi is difficult to farm even in ideal conditions, it fetches an exorbitant price.
When we purchased several brands of wasabi powders and pastes from a local Asian specialty market, we were surprised to find that none contained any Japanese horseradish at all. Instead, these products were derived from the root of the same garden-variety horseradish (Armoracia rusticana) found in jars of prepared horseradish, along with additives like cornstarch, mustard, and artificial colorants. We searched harder and tracked down a real wasabi paste (we had no luck finding a powder) from a mail-order purveyor in Oregon, Pacific Farms. We then tasted the real and faux products side by side, along with some freshly grated wasabi root we threw in for good measure.
The good news: The real wasabi paste (about $3 per ounce) rated identically with the far more expensive freshly grated root (about $8 per ounce), with heat that most tasters agreed “grew in intensity” and then “dissipated quickly,” ending with a “sweet,” “grassy,” “watercress” flavor. The bad news: The impostor products (made from powder) were consistently described as “boring,” “stale,” and “metallic.”
Though we suspect these more readily available fakes are generally what you’re served in all but the most high-end sushi restaurants, you’ll have a totally different experience if you seek out real wasabi, whether in paste form or the fresh root.