Daio Wasabi farm | All about real fresh wasabi

All about real fresh wasabi

The global vogue for all things wasabi have seen products such as wasabi peas, wasabi popcorn, wasabi seaweed snacks, wasabi hummus and dips hit the shelves and becoming popular. However, maybe not many of us, know that all these years, the wasabi used in these products, the pasty green stuff that gets mixed in with the soy sauce which causes teary eyes, is actually not wasabi but horseradish. What we are being served on our platter of sushi is in fact a mix of horseradish, mustard, a little food colouring that have been reconstituted with water from a powder form. The likelihood of having ever tried the real thing outside of Japan is slim to none. If you look at the tube of paste or tin of powder that is claimed to be “wasabi” at the supermarket, you’ll find it will likely state on the packaging that it comes from Japan.

Wasabia japonica, is very rare. Even in its native Japan, demand constantly outstrips supply, and it’s expensive to import and notoriously tricky to grow. Wasabi is a member of the Brassicaceae family, which includes cabbages, horseradish and mustard. This very pungent green fleshed root is used grated as a condiment, particularly to accompany sushi. Its hotness is more akin to that of a hot mustard than the capsaicin in a chili pepper, producing vapours that stimulate the nasal passages more than the tongue. Its flavor is extremely perishable. Real wasabi is crammed full of potassium, calcium and vitamin C.

So what is the real deal?

Real wasabi (Wasabia japonica, or Japanese horseradish) is native to Japan, where it has been cultivated for at least a thousand years. It is extremely difficult to cultivate and the plant will not grow outside of Japan as it grows only in clear running water in high altitudes above 1000m. Another issue is that it takes 2 years for a single plant to reach maturity. These factors combine to make the cost of real Wasabi at up to $200 per Kg, far too expensive for the average restaurant or sushi lover. For these reasons, genuine wasabi is expensive and is rarely seen outside of Japan. The wasabi has a lot of spicy relatives. It’s a member of the Brassicaceae family, along with broccoli, kale, cauliflower, Brussels sprouts, mustard, and (European) horseradish. And it’s the European horseradish that we normally get with our sushi platters, ground into a nose-tingling paste, with an added dash of mustard and a splash of green food coloring. Wasabi and European horseradish are similar in the taste and pungency but wasabi is hotter and greener. A prime constituent of both is the sinus-zapping allyl isothiocyanate, where the heat is felt in the trigeminal nerve near the nose rather than in the back of the throat.

What is the difference then between wasabi and horseradish?

For one thing, the ingredients of real wasabi are volatile. The real wasabi stems lose potency 15 minutes after grating. Horseradish, on the other hand, stays hot for hours. Real wasabi has a more refined hotness, a sweet after-taste and is not nearly so bright a green as horseradish. Real wasabi starts to lose its flavor just minutes after grinding. It can’t be stored long enough to get it to supermarkets or home kitchens in paste form, and most people don’t know how to grind wasabi roots, which can makes it hard to get the right amount of wasabi into their dishes.

Why use horseradish?

Horseradish solves all of these problems. Horseradish becomes a good substitute with the right flavour profile and the most convenient way to capture that heat is to buy “wasabi” paste in a metal or plastic tube—one that won’t retain any air, which hastens the loss of flavor. The paste can be stored in the refrigerator with a shelf life of a few months. Wasabi powder will keep in its tin in a cool, dark place for several months too. As such, today, horseradish from Japan is exported as wasabi in the paste and powder format mixed with a little mustard, cornflour and food colouring.

Being able to get your hands on real wasabi would be a treat but the truth is, real wasabi is rare outside of Japan. Hence the product we most often use isn’t real wasabi—but it probably is the flavour we know and love. Wasabi paste today is used to compliment sushi, sashimi, and other Japanese dishes like soba noodles and added to salad dressings or even tempura batter. You can stir it into ketchup, mayonnaise, or guacamole for a hot spread or a spicy dip, or whisk it into soy sauce or  make a marinade for beef.

We had the privilege of visiting a real wasabi farm in Nagano and it further deepened my understanding why real wasabi is so rare hence so expensive and hardly available outside of Japan.

Daio Wasabi farm (3640 Hotaka, Azumino, Nagano Prefecture 399-8303, Japan)

Daio Wasabi Farm is 155,000 sqm in size and it is the largest wasabi farm in Japan, producing 130 tonnes a year, 1/10 of the total Japanese production. The idyllic scene of old-fashioned, wooden water wheels alongside the river at the Daio Wasabi farm in rural Azumino City in Nagano just made wasabi that little more special. The farm has multiple large fields with a meticulously maintained network of small streams that constantly provides each wasabi plant with clear, flowing water from the Northern Alps. Only under such pristine conditions is wasabi cultivation possible. The farm is spread out over a wide area, with a restaurant, small shrines and shops linked by winding paths. It’s very peaceful and picturesque place to walk around. The whole area is surrounded by the stunning snow capped Japanese Alps. We were hosted by Wasabi Master Shigetoshi san, who is also the Chief Storyteller and Farmguide. I must say, our wasabi master is one hip and charming man that reminded me very much of Richard Gere.

An idyllic scene of old-fashioned, wooden water wheels alongside the river can also be enjoyed from the walking trails. The water wheels were constructed here for the filming of Kurosawa Akira’s “Dreams” in 1989 and have been left standing. Only pure pristine  mountain water flowing at a constant temperature may be used in the culture of wasabi. Daio Wasabi Farm cultivates wasabi plants using crystal clear snow-melt from the northern Japanese Alps.  The temperature of the water of Daio Wasabi Farm is kept 13℃ all year.

Outside of Japan, the site is best known for its appearance in the 1990 film Dreams by world famous director Akira Kurosawa in the segment called “Village of the Watermills”. Just next to the waterwill, is a huge piece of rock/stone. According to our host Shigetoshi san, it was on this stone, Director Kurosawa san sat to direct the film and where he would call out “ACTION!” Today it is known as  Kurosowa stone or the Dream stone paying respect to the great director.

An old picture taken in 1917. According to Wasabi Master, the farm was previously a nashi pear farm. Due to constant flooding, it was converted to a wasabi farm. This place was just not suitable for other types of vegetables. It took 240 people to help built the dykes around the farm in winter. The farmers would be working elsewhere to grow vegetables and only were free to help in winter.

There are row upon row of flooded gravel beds with the cold clear water slowly moving through them, which is what the wasabi needs to grow. Wasabi growing is backbreaking work. It needs a constant temperature, so it has to be located at a certain altitude (well over 1,000 metres in some cases) as extreme heat and cold are not welcome. From May to October, the fields are protected from the sun by black mesh nets.

Above the plants about 1.5m high is black mesh net. Fields need constant care during the two years it takes for roots to be mature. The whole field is covered with a black mesh net to protect it from too much exposure to the sun. These nets are stretched over the field only when it is directly under the path of the sun.

The Three Musketeers (Me, Junko and Rie) all ready to descend onto the wasabi fields, suited in our Wellington boots!

Wasabi plants growing on the highly manicured artificial stream beds, where rows of rocks are made into mounds, like soil would be for most other crops. Between the rows of rock is a constant stream of fresh clear water that comes down from the Alps.  On each mound two wasabi plants are planted one on each side closest to the water.

Me seen here in action with Wasabi Master. The plant is very strong. It takes a lot of effort to actually pull the whole plant out . The plant itself consists of the rhizome or root and clusters of long stemmed heart like leaves. After 2 years the wasabi plant matures to almost one metre in height, root, stems and leaves included. Subsidiary plants will grow from the bottom of the main large root. These will be cut out to be replanted. The large root will be harvested for the wasabi paste. The stems will be pickled in Japanese sake to  become “Wasabi Tsuke”, a delicacy one can use to season his/her bowl of freshly steamed rice.

Like ginger, turmeric, and galangal, the part of the wasabi plant with widespread culinary use is the rhizome, the horizontal plant stem that produces the roots of the plant.

After a brisk washing in lots of cold water, Wasabi Master deftly trims away the leaves (which are edible), cutting the rhizome just below the base stem and holds out a knobby, 3-inch-long, greenish, root-like object: the coveted wasabi rhizome.  The rhizome serves as storage for the plant’s nutrients and is where the flavors tend to be most concentrated.

Wasabi Master explained to me how the wasabi rhizome grows. The green stems on the top would slowly become the wasabi rhizome. This is why we can see the knobs on the rhizome. The knobs seen are where the stems used to be.

How To Grate Wasabi properly?

Wasabi on a metal oroshigane: It grates down to a sticky purée – more adhesive than horseradish.  Now, where do you grate the stem from? The pointed end or the stem end? Wasabi Master says usually after chopping the stems away, the root is first grated from the top stem end as it will hotter as you come closer to its pointed end nearer to the root.

Oroshiki grater made with shark skin: The traditional way to grate the wasabi root is on a wooden paddle covered with shark skin. There are two essential tips to getting the best possible experience from fresh wasabi paste: it has to be made fresh, and it must be grated to just the right texture. The importance of correct grating can’t be overstated. The prized flavour and incredible aroma of wasabi is created by ‘tearing apart’ the individual wasabi cells and mixing the ingredients within. This releases the volatile compounds and after giving the paste a few moments to rest and develop its flavour. To achieve just the right texture, a very fine grater is needed. Utensils such as cheese or Nutmeg graters just don’t do the job properly as they are too coarse and ‘slice’ rather than ‘grind and mix’. When grating, the wasabi is held at 45 degrees to the surface and grated in a circular motion as this achieves a good balance of grinding and mixing. The sharkskin surface with its teeth and nubs acts like a sandpaper to give a beautifully smooth texture to the fresh wasabi paste.

A little pile of grated wasabi, a lovely, light shade of green. (It really is green; the color comes from chlorophyll, since despite its root-like appearance, the rhizome grows above ground.)  Wasabi master got us to try the different wasabi from the different graters. There was indeed a stark difference in terms of the sharpness.  He told us it was important to let grated wasabi rest for one to two minutes. This allows the wasabi’s flavor to develop; the flavor-producing compounds react following grating and exposure to the air. They’re extremely volatile, though – meaning that fresh wasabi loses its pungency and hot flavor in about 20 minutes. It must be eaten freshly grated! It’s strong and hot, but with no harshness and no lasting burn. Plus, it tastes green, herbal, distinctly plant-like; it’s a very clean, pure flavor.

Daio Wasabi Farm: I love how cool Wasabi Master is and the experience was certainly an unforgettable one.

Innovative ways to have wasabi

I had to try the wasabi ice cream while I was at the farm. It was one refreshing spicy ice cream!  I rather enjoyed my ice cream. It tasted lightly sweet with a plant like flavor. Towards the end, the wasabi flavour became stronger.

The unique item we had was a wasabi beer, yeap, wasabi beer with little shredds of wasabi in it. So how did it taste? HERBAL AND SPICY! Nasal clearing and really not my kinda of beer! It was however very innovative.

Wasabi juice was actually lime juice with wasabi paste ice cubes. The lime juice came through strongly with a little spiciness that is distinctive of the sweet mellow wasabi. The lemon and lime made it a really refreshing drink. I liked this!

Daio Wasabi Farm has a soba shop which serves fresh Wasabi related dishes. Soba is one of the main food in Nagano made with pure water from the Kitane Alps.  Chilled soba with fresh real wasabi is the best!