Most people know Wasabi as that green spice served as a condiment to sushi dishes. However, there is a very high probability that every instance of this paste you have ever tasted is not true wasabi, especially so if served outside of Japan. This is because true wasabi is incredibly rare and pricy.
The main reason for its rarity is the Wasabia Japonica plant, the rhizomes of which are used to produce Wasabi. This plant is notoriously difficult to cultivate and is in fact considered by most experts to be one of the most difficult plants in the world to grow commercially. This is because the plant needs to be partially submerged in moving water and, as a result, only grows in rocky riverbeds in the valleys of Japan in the wild. It is also extremely sensitive to even the slightest changes in its environment or humidity, and is also susceptible to diseases. As a result, the plant is extremely rare, with its demand far exceeding the amount that can be cultivated and supplied to the market. In fact, a single kilogram of the rhizomes can cost in excess of USD 160 (approx. OMR 62).
It is this excessive cost that all but ensures most restaurants only serve substitutes, which are usually a mixture of horseradish, mustard and food colouring. There is a significant difference in taste between the substitute and the real thing. Real freshly-grated Wasabi has a fresh herbal taste and while pungent, is delicate enough that it doesn’t overpower the natural taste of the dish it is served with. The hit of heat it delivers also does not linger. The substitute on the other hand, has a much harsher taste with a lingering, burning aftertaste, which if not properly balanced, or if overused, can easily overpower the dish itself. As a result, it tastes nowhere near as good as authentic Wasabi.
Real Wasabi is ground from the rhizomes of the Wasabia Japonica plant and is available primarily in three forms – as a paste, powdered, or the Wasabi rhizome itself. The paste is available in a squeeze tube similar to a tooth paste and is ready to use right out the tube. The powdered version is cheaper than the tube variety and not quite as good, but both versions are far better than the substitutes. The whole rhizomes are the hardest to find and easily the most expensive. They are usually freshly ground using a device called oroshiki (shark skin paddle) right before the dish is eaten, and is the preferred way of serving Wasabi. This is because Wasabi is known to lose its fresh flavour within 15 minutes if left uncovered. This is also why most high-end restaurants that server real wasabi, grind it right there on the table in front of guests when serving the dish.
So, if you ever find yourself in Japan and you love sushi, do try and find a place that serves authentic Wasabi. While hard to find and pricey, it will be worth it for that once in a lifetime authentic sushi experience.
