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Japanese horseradish wasabi is one of the strongest spice and one of the most expensive vegetable in the world.

The oldest mention of wasabi comes from Japan, from 794. It was a mountain medicinal herb, precious like the famous ginseng root and considered to be a drug which primarily became famous as an antidote especially to the treacherous fish meat - in Japan very often eaten raw - and seafood. That is why wasabi got widely accepted only with the popularization of sushi and sashimi in the Edo period, and some 400 years ago it became an important cultivated plant. It was also the fashion for sushi that made the modern world know wasabi, without which sushi actually does not exist.


Raw wasabi rhizome


Wasabi (Wasabia Japonica) belongs to the family Brassicaceae, comes from Japan and is related to cabbage. It is a long, slow-growing perennial with a rooted thick rhizome, long stalks and large leaves. It naturally grows in cold mountain streams and it is also cultivated mostly there. Its green "root", or rather a creeping rhizome or stem grows up to knee height and creates a thicket in a manner similar to Brussels sprouts. Long stems growing from rhizomes grow to a length of 30 to 45 cm and can reach a diameter of 12 cm. The stems have a single heart-shaped leaves that can reach the size of a small plate. During the growth of rhizomes, lower leaves gradually fall. The plant matures after two-three years. After the initial phase of growth, the rhizome starts to store nutrients, reaching with two years the volume of 15-20 cm. Depending on the climatic conditions, up to 20 root suckers may grow from wasabi axil buds. In the case of cultivation in ordinary soil, rhizomes of inferior quality are obtained, they are mostly directed only to processing. Wasabi rhizomes can be light green or darker - depending on the variety chosen.


Harvesting wasabi


Wasabi is a very delicate plant, demanding in cultivation. It prefers cool, moist conditions occurring in the misty mountain streams. It hates both frost and heat. It normally requires air temperature between 8° C and 20° C as well as high humidity in summer. It does not tolerate direct sunlight and therefore is grown under a canopy of natural forests or in an artificial shadow created with mats or sheets stretched. It requires 30% light and 70% shadow. In Japan, the most precious wasabi is cultivated by families in mountain villages, where the artistry of this cultivation is passed from one generation to another.


The most expensive vegetable in the world


There are two main methods of cultivation of this plant. Wasabi of better quality, in terms of both taste and appearance, grows in cool mountain streams and is known as a semi-aqueous plant (sawa-wasabi). In Japan, the roots of this species are extracted in a layer of gravel, amongst others on the slopes covered with a thin layer of flowing water. Wasabi plots are tiny terraces built of stone, with difficult access in the mountains, where you can not use any machines and where also the regular repairing of terraces - usually after violent mountain floods in spring and after earthquakes, numerous in Japan - have to be done manually. Seedlings are planted manually on the terraces, then they absorb nutrients from the water. Water is the most important: it must be perfectly clean, coming from the snow thaws, rich in minerals extracted from volcanic soil, kept at a temperature of approx. 13° C throughout the year. Each stone terraces, where the wasabi is cultivated, is used for precise filtering of water through the gravel and sand. The quality of the rhizome is known by the scars that remain over its entire length after the discharge of the leaves. If they are rare, it means that the horseradish was growing too quickly and is too watery. If there are too many of them, it means that it was growing too slowly and it will be too spicy. Best rhizomes can cost even 5,000 yen apiece.


Wasabi fields in Nagano Prefecture


The second type called 'oka-wasabi' is cultivated on flat fields in various conditions, and is usually of poorer quality. In Azamino in the prefecture of Nagano, where are situated the biggest wasabi growing areas in Japan, blinds are stretched above the fields of water to protect the plants from the gusts of freezing winter wind and the scorching heat of the summer sun. The plants mature faster here, and they can be collected already after 16-18 months. To work in the fields you have to wear wellingtons and wasabi is harvested all year round. It is said that the taste and smell of wasabi depends on the time of harvest. In winter, the growth of rhizomes slows down and then they keep more ingredients inside, so they are tastier. Under optimum conditions, wasabi reproduces by seed, but in commercial farms little suckers, that appear on the plant during its maturation, are being transplanted.


Attempts of artificial cultivation


Cultivation of this species on a larger scale is conducted outside Japan only in a few places in China and Taiwan. Although producers in the USA, Canada, Tasmania and New Zealand have invested in the production of wasabi in hydroponics, but the production of wasabi in conditions other than natural is associated with high costs, which is reflected into the price of the product. Wasabi is one of the most expensive vegetable in the world. "Roots" or rhizomes constitute the traditional spice to prepare sushi. Also its leaves and petioles are used as an additive to food products - marinated, or dried.

Most commercial wasabi products in the West (also in Poland) are fake. Yes, they look like the original light green paste served with sushi, but mostly it is a mixture of common white horseradish, mustard and artificial colours. Today, the demand for real wasabi highly exceeds the supply and even Japanese companies are often counterfeiting or partially "complementing" it. Its powdered form is the most popular, especially in the West. To buy genuine, fresh wasabi, even in Japan you need to have both knowledge and skills, because there are many prices and even more fakes and combinations.

Counterfeits are so common, because the taste and properties of both horse radishes are in fact similar. Of course, wasabi is much stronger and beats strongly in the top of the palate, to the nose, but, trying two flavours, even the greatest layman will find that these two plants are closely related. Everybody admits as well, that the smell and taste of wasabi is much fuller and much more "herbal" than the flavour of ordinary horseradish. Compared with wasabi, our common white horseradish has a much larger root, it grows in the fields, matures more quickly, giving much higher yields, and can be harvested for 6-7 months a year.


Ginger and wasabi on a plate for sushi

If you manages to buy a fresh wasabi rhizome, you should treat it as a fresh horseradish root - wipe it off only as much as needed. Traditionally for this purpose you should use oroshi, which is a curb made of pine slat with... a shark skin nailed on it. Such use of the skin of this fish is known in Japan since ancient times and it is still considered to be the best method of extracting the greatest taste, texture and consistency of freshly ground wasabi rhizome. Today, however, you would rather apply ceramic or stainless steel graters (oroshigane). The smaller and thinner their teeth is, the better the result can be obtained.

If you bite a piece of wasabi rhizome, you will feel the very bitter taste, but it will not reach to your nose. It is only the grating that disrupts the plant's cells and releases volatile compounds, which, moreover, quite quickly dissipate and disappear. The best way to minimize their loss is using traditional graters with shark skin and grating the rhizome with circular motion at an angle of 90 degrees to the grating surface. The "root" should be grated from the top, from the side of the cut foliage - where it is most juicy and has the freshest taste, the rest of which "escapes" to the remaining rhizome and lasts for the next grating. Having grated the required amount of the substance, you have to form a ball and leave it at room temperature for a few minutes, so that the flavour has the opportunity to fully develop. The taste of wasabi appears in a short time, and then disappears, therefore you should grate only as much as you can use in the next 15 or 20 minutes. The grated root forms a spicy paste, but may be mixed with other ingredients and added to the vinaigrette sauce, mayonnaise or other spices. Sprinkle the wasabi root with water and wait a moment to let the flavour compounds extract themselves. Keep it at a low temperature, in an airtight container or bag.



Wasabi on a grater with shark skin


Wasabi is necessary to prepare sushi and sashimi. However, you need to be careful when dosing, because it is many times more spicy than the traditional horseradish from a jar. Wasabi paste has power comparable with freshly grated traditional horseradish. The spicy and unusual flavour of wasabi is formed by isothiocyanates, mainly the sinigrin. These compounds arise from glucosinolates permanently present in the cells but not exhibiting any biological activity. It is only the damage of tissue that initiates oxidation and leads to their transformation into isothiocyanates. This synthesis is a two-step one, at first emerges the unstable aglycone. This reaction is catalyzed by the enzyme - myrosinase. Then, at neutral pH, the aglycone decomposes to isothiocyanate.


Wasabi paste and soy sauce


Wasabi has a various culinary usage. Most people taste it for the first time with Japanese dishes such as sushi, sushimi and other raw fish dishes, as well as buckwheat noodles (soba). It is hard to imagine them without wasabi. Pastes from grated wasabi are used for all these applications, in addition to pickled ginger and soy sauce. Increasingly, however, wasabi is also used to emphasize the taste of a variety of meat and many other foods. We can use it as an alternative to the classical Polish horseradish, but in a smaller amount (unless you're tough guys). Wasabi perfectly corresponds with red meat, cold cuts, white sausage, egg, in fresh vegetable salads, soups (rye soup, white borscht), with hot and cold sauces, soy sauce, mayonnaise or yogurt. However, given the form of powder - it was, it is and it will be used mainly for sushi, which can also be recommended to everybody preparing this dish at home, as well as to chefs at the sushi bar.

The Wasabi powder we offer is an original Japanese product from reputable manufacturer S&B and contains authentic wasabi horseradish. Its powder form is a very good solution because you can prepare the amount of spice, which you need at the moment. A thirty-gram package is ideal for home use and quiet enough for a big event involving sushi.



S&B wasabi powder (30g can) available in the Cuisines of the World delis and web shop


Wasabi shoots marinated in rice vinegar


Wasabi zuke


In Japan, wasabi leaves and petioles are used for the preparation of a special marinade. The raw material is washed and cut into pieces, which are poured with cooking salt and left for an hour under a heavy stone. Then the weight is removed and leaves are washed to remove the excess of salt, then drained and poured with a mixture of fine vinegar, sugar, and soy sauce, and then sealed in a vessel and left for several days in the refrigerator. The product obtained is darkened, slightly rosy, fragrant, crumbly marinade combining the taste of sweetness, acidity and spiciness of the herbal horseradish. Another product made of with chopped leaves and stalks well-known in Japan is wasabi-zuke, a marinade in a mature rice vodka - sake, or kazunoko - wasabi leaves pickled with herring roe. All dishes with wasabi must be avoid like the plague the high temperature, because then the taste and smell disappears, like other properties of this plant.

Wasabi is so strongly rooted in the culture and traditions of Japan, that there is also a beer with the addition of wasabi, wasabi puffcorns and even... wasabi ice cream. Antibacterial properties of wasabi are the reason why in Japan they are added to the tissue paper, which protects the boxes of take away dishes, and due to the fact that people are particularly sensitive to the smell of wasabi, the powder is to the alarm devices, for example to the firefighting systems, thanks to which the deaf and hard of hearing people are waken up after two minutes from turning on this spray "fragrance alarm". As they would not hear the acoustic alarm.



Wasabi ice cream


In addition to the unique role as a condiment or a dish, wasabi also presents a number of potential health benefits. Many studies have shown that the active ingredients in wasabi - A provitamins (positive effect on the eyes), as well as B vitamins, vitamin C (a powerful antioxidant that strengthens resistance) and sulfur compounds (bactericidal properties) - are able to kill a number of different types of cancer cells, reducing the possibility of clots in the blood and trigger the body's defences, by removing the cells, which have not entered mutation. The antibacterial and antifungal effect of wasabi has also been confirmed, as well as its capabilities to prevent food poisoning.

Studies also indicate that wasabi helps reduce the secretion of mucus, so it can be used in support of the fight against asthma. A unique ITC group contained in wasabi includes long-chain methyl isothiocyanates, which are rare in the diet of most people today. The long-chain ITC support the natural function of the liver and the detoxification of digestive tract. Rich in beta-carotene and glucosinolates, it also kills some forms of e-coli and Staphylococcus bacteria, supports detoxification and helps preventing tooth decay.



Asparagus with hollandaise sauce on the basis of wasabi


As a potent antioxidant, wasabi is the subject of many scientific studies. Evidence suggests that glucosinolates and the products of their hydrolysis are effective in reducing the risk of cancer, by helping the immune system to fight against the mutagenic cells.


 Wasabi powder (300g bag) available in the Cuisines of the World delis and web shop

Wasabi paste (43g tube) available in the Cuisines of the World delis and web shop

Wasabi powder (1kg bag) available in the Cuisines of the World delis and web shop