Japanese Horseradish is a plant of the Brassicaceae family, which also includes horseradish. A paste made from its ground rhizomes is used as a pungent condiment for sushi and other foods. It is similar in taste to hot mustard or horseradish rather than chili peppers in that it stimulates the nose 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. The oldest record of wasabi as a food dates from the 8th century CE. The popularity of wasabi in English‐speaking countries has tracked that of sushi, growing steadily from about 1980.
Due to issues that limit the Japanese Wasabi plant’s mass cultivation which increases its price causing limited availability, the Western Horseradish plant is generally used outside of Japan in place of the Japanese Horseradish. This version is commonly referred to as Western Wasabi in Japan.
It is thought that wasabi was first cultivated in the early Edo period. Upon being presented with wasabi, Tokugawa Ieyasu, said to have been a gourmet who lived a comparatively long life, fell in love with the ingredient and since the wasabi leaf resembled the hollyhock that was used as the Tokugawa family crest, he is said to have treasured the plant, keeping it inside his territory. During the Keicho era (1596 to 1615), Utogi (currently Shizuoka-Shi) was founded upstream from the Abe River with Mochizuki Rokuroemon as head. It is said that the history of wasabi cultivation began in this area.
Wasabi is first thought to have begun its use as a seasoning for sushi during the Bunka/Bunsei era of the Edo period (1804 to 1830). The idea of hand‐formed sushi with wasabi, resulted in a sushi boom throughout Edo, which then spread to the common people. At that time there were no refrigerators or refrigerated facilities, so it is thought people used wasabi because they knew from experience that it acted to reduce the fishy smell of food, stopped bacteria from growing and prevented food poisoning.
As refrigeration and distribution technologies had not yet developed during the early Taisho period, society took a hint from tea processing and began drying and powdering wasabi. After that, powdered wasabi made from horseradish was developed. In 1971, this developed into wasabi paste and finally in 1973, developed into fresh grated wasabi which uses the kind of wasabi mostly used today.