Forget cinnamon. The mere mention of wasabi can make even the most ardent fan of Japanese cuisine curl their toes. The extract of the stem of a plant from the same family as mustard and horseradish, wasabi is hot – but it’s more of an olfactory heat, affecting the nasal passages more than it does the tongue. As a condiment – Japan’s equivalent of ketchup, mustard, or relish – wasabi is an exercise in both courage and moderation, as taking too much of the extremely pungent green substance brings with it its own unique brand of instantaneous punishment.
Wasabi must be made into a paste before being consumed. It can be bought that way, or it can be bought in the form of a finely ground powder, which must be prepared as a paste before being served. Finally, one may purchase fresh wasabi stems – a popular item in many Japanese markets. Some connoisseurs insist that freshly prepared wasabi entails a much higher quality, while others claim to be unable to tell the difference. It is possible that there is a genetic “quirk” causing some people to perceive nuances of the wasabi flavoring which are imperceptible to others.
This is unproven, but if found to be true, it would place the wasabi plant in the company of such items as broccoli: approximately 9% of individuals worldwide possess a genetic trait which causes them to pick up on an additional bitter flavoring in broccoli which most people cannot detect. Similarly, a significant minority of people (approximately 20%) cannot smell the stereotypical “bitter almond” scent given off by cyanide.
Eat too much wasabi at once, and you might wish for some cyanide… but back to the topic at hand.
Fresh wasabi loses its flavor in as little as 15 minutes of left uncovered. For that reason, when it is offered in a high-end restaurant, the powder to produce the wasabi paste will be ground when the customer places an order calling for the condiment, not before. At sushi restaurants, where preparation can be time-consuming, chefs typically place wasabi between the fish and the rice, as covering it up helps to preserve its flavoring for longer.
As a curious side note, fresh leaves from the wasabi plant can be eaten, and have the same spicy flavoring as the stems, but they are seldom marketed as anything more than a casual snack item. Roasted beans, nuts, and other legumes are sometimes sold as a snack item having been dusted with wasabi powder.
In fact, many western fans of wasabi have never actually tried genuine wasabi paste. The plant requires a wet environment to grow, and is both difficult and inefficient to cultivate; this makes it relatively rare, as well as being an expensive commodity. Outside of Japan, genuine wasabi is extremely rare. What most westerners would have tried, which is marketed as wasabi in places such as the US, Canada, and Europe, is a mixture of horseradish, mustard, and starch, touched up with some green food coloring.
The horseradish and the mustard combine to produce a similarly pungent flavoring to their more exotic cousin, while the starch lends thickness and texture that the other ingredients lack.
While the flavoring is comparable, and the texture is approximate, true wasabi (in addition to being naturaly green) is considerably hotter than its more familiar western cousins. In the west, it is typically available only at high-end markets and expensive Japanese restaurants.