Photo Copyright 2015 LuxNiseko
Wasabi Sprout
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It was not long ago that wasabi was a mysteriously exotic ingredient found in the rare Japanese restaurant found outside Japan in large cities like HongKong, Los Angeles & Paris.  In the last 20 years there has been an increasing number of  Japanese restaurants opening throughout the world.  Previously unheard of ingredients like pickled ginger, miso and wasabi have now become accepted as normal condiments for food.  For most people living outside of Japan though wasabi remains a mysterious green spice blend that appears on a plate of raw fish or hidden between the thin slice of fish and shari (vinegar rice) of sushi.  It is still rare to see the real wasabi root freshly grated in front of the customer.  Rather a paste squeezed from a tube or mixed from dry powder is the norm.  Unfortunately these pastes contain very little wasabi and none of the fresh aromatics the real root provides.  Within Japan’s borders freshly grated wasabi is the norm in all but low-budget restaurants like kaiten-sushi and izakaya and of course at home where fresh is considered as a luxury ingredient.  What makes wasabi special is however only found in the fresh version grated correctly and just prior to eating.  It is not a common ingredient even in its indigenous home country which can be put down to cost and rarity.  You see – wasabi is very difficult to grow, labour intensive and takes up to 2 years before it is ready.

Wasabi Japan
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Wasabi is an indigenous herb of Japan and mainly cultivated in cool mountain plateau regions where the spring water temperature is kept cool all year.  The key to growing good wasabi is controlling the flow of water. A sufficient volume of water must flow evenly. In places where there is not enough water, as well as in years of less rain, the roots do not grow large.   Another difficulty with growing wasabi is it does not grow well in places where the water splashes.  Stone and sand gravel over which water can flow smoothly are best suited for wasabi growth.  The water must always be spring water, with little temperature variation year-round.  Ideal temperatures are between 11 and 19 degrees Celsius.  Although wasabi is fairly resistant to cold it will freeze if the temperature falls to -5 degrees Celsius.  Similar to rice wasabi is grown with only water and no fertilizers, so the quality of the water is most important.


Wasabi Forest
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A Brief History of Wasabi Farm Japan

Cultivation of wasabi farm Japan began in ancient Japan history.  Wasabi represents a dietary tradition that has been nurtured by generations of people who have coexisted with nature, most often in rural mountain areas like Nagano.  A discovery of an old wooden board from around 685 had writing about wasabi on its surface.  This wooden board proves that cultivation of wasabi has started at least 1300 years ago.  Japanese oldest code law, Taihouritsuryo, also indicates wasabi was one of the items that people could render for tax purposes.

Generations ago Japanese ancestors cleared thickly populated forests, dug step fields into the stony earth of the mountain, carried stones from nearby river banks, and then constructed stone-lined fields on the steep mountain slopes.  Every wasabi farm Japan has its own cultivation method often handed down from generation to generation.  In Yamaguchi, Shimane, and Hyogo Prefecture wasabi is commonly grown in keiryu style fields located in or beside sloping mountain streams.  Another style seen in our photographs here is the jizawa style which is still seen in the Okutama area of Tokyo as well as in Yamanashi Prefecture.

Wasabi Field
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Specialty Wasabi Farm Japan

Wasabi is very sensitive plant to grow and requires a very specific climate condition.   Cool temperature, fresh running mountain water and small pebbled soil are the three main conditions that must be met. “Sawa” of “Sawa-wasabi” means mountain stream in Japanese language which is why wasabi is often called as “Sawa-wasabi”.  It takes about a year to a year and half to harvest each wasabi root making it a very low yielding farm product.  Most of the global wasabi harvest comes from wasabi farm Japan regions like Shizuoka, Nagano, Iwate and Shimane prefectures.

In some ways wasabi is perfectly suited to the premium specialist farms of Japan that tend to focus on perfecting quality rather than quantity.  One such farm is the Daiõ Wasabi Farm.  It lies on the peaceful outskirts of Hotaka town in Nagano and is recognised as the largest such farm in Japan.  Founded in 1915, the farm has enjoyed a long history throughout the years that has even seen it featured in the 1990 film Dreams, directed by the internationally acclaimed director Akira Kurosawa.  The quaint watermills that were especially constructed for the film remain in the farm today, and can be best viewed by taking one the special raft-tours that are available throughout the spring and summer months.

While the Daio Wasabi Farm Japan has long been a favourite of Japanese tourists for its picturesque beauty, the farm is also known for a multitude of culinary delights offered in its restaurants and shops. Visitors can try traditional staples such as wasabi soba (buckwheat noodles) and wasabi tempura (deep-fried prawns and vegetables), to the slightly less conventional likes of wasabi ice-cream and wasabi wine.  The wasabi ice-cream is a perfect example of just how food fresh grated wasabi can be as it captures the fresh and sweet, sensitive bouquet of wasabi without ever feeling hot and spicy.

In North America Pacific Coast Wasabi has growing operations located in British Columbia, Michigan, Washington and Oregon.  Pacific Coast Wasabi grows only high-quality semi-aquatic Wasabi for the culinary, nutraceutical and natural product markets.  While most wasabi farms in Japan are grown directly in real natural streams the Pacific Coast Wasabi Operation spent many years developing and fine tuning a new Wasabi growing methodology that produces sawa quality Wasabi without the need for rivers and large volumes of water.

Wasabi Stream
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Health Benefits

Scientific research has shown that Wasabi produces a suite of biomedically active molecules called isothiocyanates (ITCs) which are powerful nutraceuticals. These compounds, particularly the long chain methyl isothiocyanate, 6MITC, are most abundant in authentic Wasabi. It is these ITCs that are responsible for the flavour and heat of real Wasabi as well as the unique health benefits including: anti-allergies, anti-oxidant, anti-cancer, antibiotic (ulcers), anti-inflammatory, immune boost and anti-coagulant. In addition, other natural compounds from Wasabi are effective in bone calcification and collagen synthesis.

Young Wasabi
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Difference Between Fresh & Preserved

Like many food products there are varying qualities and freshness of wasabi to be found.  Most restaurants outside of Japan offer a preserved form of wasabi usually found as a paste in tubes.  This is a mixture of dried wasabi, corn starch and sugar with green coloring added to make it look like the real thing – sometimes horseradish is added to add heat or reduce the cost.  Tube wasabi is significantly different than fresh.  If you have the opportunity always choose fresh over powders or pastes. Grating Wasabi releases volatile compounds, has better texture and consistency that distinguish fresh wasabi from the imitation products of powdered and paste horseradish, which have been mixed with Chinese mustard and green food coloring.

Living in Japan, one can find fresh wasabi in city markets and most fresh produce markets.  Just like vegetables and fruit there is a subtle difference between wasabi procured from different farmers.  Location also plays a role in the quality of wasabi with the best coming from areas with mountain fed streams.

Wasabi Mountain Stream
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How to Store Wasabi

Fresh wasabi is best kept in conditions similar to how it was grown.  That means damp, cool and away from light sources.  The easiest way to achieve this at home is to wrap in damp newspaper or paper towel and store in the humid drawer of the the refrigerator.  Each time the wasabi is used wrap and store just as before.  Occasionally the paper towel may need to be changed to prevent odors from damaging the wasabi.  Kept in this way the wasabi should be fine for up to 2 weeks.

Wasabi Grater
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Three Parts Of Wasabi Root

When you look at wasabi which part would you imagine to be the sweetest?  Wasabi grows from its stem forward into the ground and so the newest and sweetest part is closest to the stem.  The middle section is slightly more spicy and the tip is both the oldest and spiciest part.  Sushi chefs take advantage of this knowledge by mixing different blends according to the desired degree of spice.  For balance all 3 sections are mixed together whereas for a sweeter blend only the stem section is used.

Grating Wasabi
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How to Grate Wasabi

Before grating the wasabi rinse, dry and then thinly shave any dark or hard parts on the skin.  Do this by firmly holding the tip in your hand with the stem end touching the cutting board.  Once the hard outer skin has been removed you may begin grating.  The ideal grater is also the most traditional.  It is a wood board with coarse, dried shark skin stretched across it.  To grate the wasabi rotate the root in a circular motion while applying downward pressure.  The circular motion breaks the long fibre resulting in a creamy textured paste.  It is the same motion used to grate daikon and ginger.  If you cannot find a sharkskin grater then a fine toothed metal grater will also do the job.

To obtain the best flavour, texture and heat of sawa Wasabi the rhizome must be ground into a fine paste. In Japan the traditional method for grating Wasabi uses a sharkskin grater or “oroshi“. If a sharkskin grater is not available, ceramic or stainless steel surfaces can be used. The important component of the grater is the teeth or nubs. Smaller teeth produce a finer paste that increases the unique heat and flavour of fresh Wasabi. Grating Wasabi releases volatile compounds, called isothiocyanates that gradually dissipate with exposure to the air. These compounds are not found in Wasabi until after the cells of the plant are broken up and turned into a paste. The finer the paste the more chemical reactions take place. Using a Wasabi grater and keeping the rhizome perpendicular to the grating surface minimizes exposure to the air.  The heat and flavor lasts only for 10 to 15 minutes, so wasabi should be grated as just before eating.

Wasabi Leaves
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Flowers & Leaves

Wasabi plants produce small white flowers between March and April.  Aside from the obvious aesthetic beauty of the flowers they provide a fresh salad a fresh spice flavor that heightens the overall taste.  The young leaves can be eaten fresh as a salad green, used as a flavour in foods or pickled fresh in sake brine or soy sauce.  Used fresh they add a sensitive spicy note that helps elevate fresh salad greens or adds a beautiful counterpoint to sweet tomatoes.  Preserved they can help frame the main ingredient with a spicy aura.

Wasabi Soy Sauce
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Role of Wasabi in Japanese Food

Wasabi first began to be used with sashimi around 1489.  In one of the earliest published cookbooks a preparation method of dipping carp sashimi in wasabi vinegar was introduced. At the beginning of the 17th century it began being used as a spice added to soba – a practice that continues to be popular today.  Only since around 1830 has wasabi been used as a condiment with sushi which mirrors the history of sushi itself.

When combined with the salt of soy sauce wasabi’s anti-bacterial qualities reduce the risk of food poisoning.  Eating raw fish and specifically raw shellfish carries a risk of bad bacteria which posed an even more significant challenge before electric refrigeration.  Even today there is always a small chance of food poisoning when eating raw fish. Wasabi’s pungent component “Arirukarashi oil” has an antibacterial effect that can suppress the growth of E. coli, salmonella, Vibrio parahaemolyticus, Staphylococcus aureus, and a number of other food poisoning inducing bacteria. Wasabi is something that Japanese have been eating for hundreds of years, served with raw foods because of its antimicrobial properties.

Wasabi and Sashimi
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JAPAN:    DAIOWASABI  1692 Hotaka, Azumino, Nagano Tel 0263-82-2118