When it comes to enjoying sushi, many people relish the experience of dipping it into wasabi, a vibrant green condiment renowned for its intense spiciness. Traditionally, this beloved accompaniment is made from the ground rhizome of the wasabi plant. However, experts have revealed that most of the wasabi available on the market today is actually fake. This raises the question: why is that the case?
Reports indicate that even the most dedicated sushi enthusiasts may have never had a taste of authentic wasabi. What they usually encounter is a mixture of horseradish and green food coloring, which is commonly marketed as wasabi.
In the United States and other regions, the vast majority of wasabi products sold are impostors. Even in Japan, it is not guaranteed that one can find real wasabi readily available, as the proportion of genuine wasabi in the Japanese market is similarly small.
This scarcity is one reason why the Michelin-starred restaurant “Mutsukari” in Tokyo stands out. Since its inception, this Japanese restaurant has committed to using only authentic wasabi.
Chef Yoshihisa Akiyama shared in an interview that fresh wasabi carries a unique spiciness accompanied by a fragrant aroma, which then melds into a smooth and creamy texture on the palate. In contrast, the imitation wasabi often found in stores tends to be overpowering and harshly pungent.
However, high-quality wasabi is becoming increasingly rare. Over the past two decades, the supply of this prized ingredient has plummeted. This decline is not solely attributed to an aging agricultural workforce in Japan and a lack of successors, but also to climate change and rising water temperatures in the growing environment, which pose significant challenges for this delicate plant.
Cultivating wasabi is an arduous process, requiring up to two years for its growth. During this period, it demands stable water temperatures and optimal lighting conditions. At current market rates, wasabi prices range from $100 to $200 per pound, and it is best consumed within a week of harvest. Consequently, many consumers opt for cheaper alternatives that can be stored for months.
Akiyama emphasizes the importance of wasabi’s freshness. Thankfully, he does not have to travel far to source true wasabi. Just under 50 miles (80 kilometers) from Tokyo lies Okutama, a town where farmers have cultivated wasabi since the Edo period (1603-1868).
The suppliers of wasabi for “Mutsukari” are brothers Hitoshi and Tatsuya Tsunoi, along with their partner. In 2020, they established a farm named “Tokyo Wasabi,” cultivating approximately 5,000 wasabi plants. They also offer daily tours that allow participants to taste wasabi freshly harvested from streams.
At 40 years old, Tatsuya Tsunoi shared that the brothers adhere to traditional wasabi cultivation methods of Okutama, which demand both time and patience. Although the flavor of wasabi is more pronounced in winter—when it is traditionally preferred—this crop can be harvested throughout the year, making its cultivation process fairly complex.
Tatsuya explained that when the summer sun becomes too strong, they provide shade for the plants. They also need to clear leaves that fall into the streams. During winter, they implement measures to protect the plants and elevate water temperatures.
He noted that climate change has made their work increasingly unpredictable. “In summer, intense sunlight can cause the plants to rot more easily, and sudden heavy rain may wash away the wasabi. In winter, reduced snowfall alters the conditions of the water bodies.”
Once they hand-harvest the wasabi, the brothers wash the plants and trim them to enhance their appearance in a procedure they refer to as “makeup.” They then cut the rhizomes to a length of about 45 centimeters, package them in boxes, and send them directly to restaurants.
As wasabi is classified as a fresh vegetable, its stem should ideally be consumed within a week. The fresher it is, the more robust its spiciness and flavor will be.
At present, “Tokyo Wasabi” primarily supplies products to “Mutsukari” and several other businesses, including their own food truck “Wasabi Shokudo” and coffee brand “Wasabi Coffee.” They plan to further expand their operations in the future.
With increasing local and global demand, the supply chain for wasabi is undergoing significant changes. For the Tsunoi brothers, an immediate priority is to increase yield; they hope to achieve this by leveraging technological advancements.
Tatsuya remarked, “We aim to ultimately combine these traditional farming methods with advanced agricultural technologies like drones.” However, in the remote area of Okutama, the initial step is to improve internet connectivity and establish 5G infrastructure.
At the same time, this secluded geographic environment is one of the factors attracting tourists. Among participants in their tours, roughly half come from abroad. Tatsuya noted that the international interest in wasabi seems to be growing annually, igniting optimism for the plant’s export potential.
Furthermore, it is worth mentioning that beyond its culinary uses, wasabi may have properties that promote hair growth and help with baldness. Japanese researchers previously discovered that a compound found in wasabi leaves, called isosaponarin, can stimulate hair growth when it comes into contact with the scalp.
It is also essential to clarify that wasabi is not the same as mustard; the two should not be confused. While both are known for their pungency, they are derived from different sources, with mustard made from mustard seeds.