Wasabi, also known as Japanese horseradish, is a plant scientifically named Eutrema japonicum (synonym Wasabia japonica) belonging to the Brassicaceae family, which includes mustard and horseradish
. It is native to Japan, the Russian Far East, and the Korean Peninsula, typically growing naturally along mountain stream beds
. The part of the wasabi plant used as a spice is its rhizome, which is the underground stem. This rhizome is finely grated to produce a pungent green paste that serves as a condiment, especially popular with sushi, sashimi, and other Japanese dishes like udon noodles
. The flavor of wasabi is sharp and hot but differs from chili peppers; it primarily stimulates the nasal passages rather than the tongue, creating a sinus-clearing sensation similar to hot mustard or horseradish
. Authentic wasabi is rare and expensive because the plant is difficult to cultivate, requiring clean water and cool climates. Due to these challenges, most wasabi served outside Japan is actually a mixture of horseradish, mustard flour, cornstarch, and green food coloring, often called "western wasabi"
. This substitute is more pungent and has a longer shelf life but lacks the subtle flavor of real wasabi. Historically, wasabi has been used in Japan since at least the 8th century AD and was originally valued for medicinal purposes before becoming a popular seasoning for sushi to enhance flavor and reduce food poisoning risks
. In summary, wasabi is a spicy green condiment made from the grated rhizome of a rare Japanese plant, prized for its unique sharp heat that clears the sinuses and complements Japanese cuisine, especially sushi
