Herb and Spice of the Week - Wasabi

Wasabi

Wasabi is a plant of the Brassicaceae family, which includes cabbages, horseradish, and mustard. It is also called Japanese horseradish, although horseradish is a different plant (which is often used as a substitute for wasabi). Its stem is used as a condiment and has an extremely strong pungency. Its hotness is more akin to that of a hot mustard than that of the capsaicin in a chili pepper, producing vapours that stimulate the nasal passages more than the tongue. The plant grows naturally along stream beds in mountain river valleys in Japan. The two main cultivars in the marketplace are E. japonicum 'Daruma' and 'Mazuma', but there are many others.

Fresh wasabi stems 

Wasabi is generally sold either as a stem, which must be very finely grated before use, as dried powder in large quantities, or as a ready-to-use paste in tubes similar to travel toothpaste tubes. Because it grows mostly submerged, it is a common misconception to refer to the part used for wasabi as a root or sometimes even a rhizome: it is in fact the stem of the plant, with the characteristic leaf scar where old leaves fell off or were collected.

In some high-end restaurants, the paste is prepared when the customer orders, and is made using a grater to grate the stem; once the paste is prepared, it loses flavor in 15 minutes if left uncovered. In sushi preparation, sushi chefs usually put the wasabi between the fish and the rice because covering wasabi until served preserves its flavor.

Fresh wasabi leaves can be eaten, having the spicy flavor of wasabi stems.

Legumes (peanuts, soybeans, or peas) may be roasted or fried, then coated with wasabi powder mixed with sugar, salt, or oil and eaten as a crunchy snack.








Wasabi is difficult to cultivate, and that makes it quite expensive. Due to its high cost, a common substitute is a mixture of horseradish, mustard, starch and green food coloring. Outside of Japan, it is rare to find real wasabi plants. Often packages are labeled as wasabi, but the ingredients do not actually include wasabi plant. Although wasabi and horseradish are similar in taste, wasabi is green and hotter. In Japan, horseradish is referred to as seiyō wasabi. In the United States, true wasabi is generally found only at specialty grocers and high-end restaurants.

Wasabi on a metal oroshigane grater

Wasabi is often grated with a metal oroshigane, but some prefer to use a more traditional tool made of dried sharkskin with fine skin on one side and coarse skin on the other. A hand-made grater with irregular teeth can also be used. If a shark-skin grater is unavailable, ceramic is usually preferred.