Archaeological evidence shows the ancient Japanese were eating wasabi as early as 14,000B.C. By the 16th century cultivation had spread, but use was restricted to the Japanese ruling class. Production increased with the rise in popularity of sushi, when wasabi became the preferred flavouring and was prized for its ability to counteract food poisoning.
The plant takes two years to reach maturity and is very particular about the conditions in which it grows. Native to mountainous areas of Japan, wasabi requires mild temperatures and dislikes strong sunlight. It is accustomed to summer shade provided by the leaves of large trees growing alongside the banks of the streams where the wasabi grows.
The mature plant consists of large heart shapes leaves, stems holding the leaves as high as 60cm, a rhizome (swollen stem) which grows above ground at the base of the plant and roots which anchor the plant firmly in place to prevent it being washed away during floods.
Wild wasabi growing alongside mountain streams takes advantage of the abundant supply of nutrient rich water, with a high, dissolved oxygen content. Wasabi grown this way in water is called Sawa wasabi and is considered to be the best quality in terms of both flavour and nutritional content. It is these conditions that we recreate in our pioneering growing system. Our wasabi takes advantage of spring water rich in minerals and nutrients, which naturally bubbles to the surface from artesian springs. Optimum conditions for growth require the right balance of sun, shade and water flow at different times of the year; careful control of these allows us to keep our wasabi free from the use of pesticides and growing in the best possible environment.
Oka wasabi is the name used to refer to the plant when it is grown in soil; this is considered to be a product of lesser quality and is more commonly used for processing as opposed to fresh consumption. Soil grown wasabi is also more prone to disease.