Real Wasabi vs Fake Wasabi: Ingredients, Key Differences, and Taste

Key Facts About Wasabi

• ~95–99% of "wasabi" in the U.S. is imitation (horseradish-based)
• Real wasabi comes from Wasabia japonica
• Authentic wasabi contains 1 ingredient only
• Imitation wasabi typically includes horseradish, mustard, starch, and coloring
• Real wasabi heat is short-lived and complex, not lingering and harsh

Fake wasabi? What are you talking about? I have wasabi all the time, right?

In the United States, various industry estimates suggest 95–99% of wasabi served in the US is imitation, typically made from horseradish, mustard, and food coloring. Real wasabi comes from the Wasabia japonica plant. Most "wasabi" served in restaurants comes out of a tube or is wasabi powder mixed with water.

At Half Moon Bay Wasabi, our plants are the only crop we've grown for the past 15 years. In this blog post, we'll take a deep dive into the different ingredients of some of the top-selling wasabi pastes on Amazon, the distinctions in taste and texture, and how to tell the difference between fake wasabi and the real deal.

What Ingredients Are in Real vs Fake Wasabi?

One of the most frequent comments we hear when selling our freshly harvested wasabi at local farmers markets goes along the lines of "I didn't know a wasabi plant looked like that", or "I never thought about where wasabi comes from."

When you have the real McCoy, only one ingredient is necessary – the wasabi itself. That's it. No additives, no coloring, no shortcuts.

Scrape off the skin (optional), grate with a wasabi grater, and you'll have a wonderful wasabi paste ready to eat. Give it about five minutes to develop—like letting a good wine breathe—and the flavor and heat will come alive. Just don't wait too long. After about 25–30 minutes, it still has a nice flavor, but the heat starts to fade.

Restaurants that serve real wasabi often grate it right in front of you.

Now, let's take a look at the ingredients listed in some of the most popular alternatives to real wasabi. Amazon lists Wasabi-O as its best-selling product under a search for 'wasabi', even AI tools tend to surface it quickly. Here's what's in the tube:

Wasabi-O Ingredients
Horseradish – 40%
Wasabi – 15%
Iodized salt – 8%
Soybean oil – 7%
Corn starch – 5%
Mustard powder – 5%
Chlorophyllins
Potassium Salts

Fifteen percent real wasabi is pretty good compared to its competitors. But you're obviously getting a lot more than you bargained for, and that will impact the taste.

Another popular brand on Amazon is S&B Wasabi. It's got a lower price point, and the ingredient list starts to tell you why:

S&B Wasabi Ingredients
Horseradish
Sorbitol
Food starch modified
Rice bran oil
Sugar
Salt
Water
Wasabi
Artificial flavor
Citric acid
Turmeric
Xanthan gum
Artificial color (FD&C Blue #1)

That's quite a long way to scroll before you get to the actual wasabi! Seeing horseradish listed first is typical for 'wasabi' that comes out of a tube and has a big effect on the taste profile. The inclusion of artificial flavor and artificial color is another warning sign that this 'wasabi' might not pair well with your sushi-grade fish or high-quality steak.

The last product we'll take a look at is Muso from Japan. Priced between the two other brands, this wasabi includes several foods other than wasabi in its ingredient list:

Muso from Japan Ingredients
Wasabi (Wasabia japonica)
Syrup (sweet potato and/or potato)
Green pea fiber
Rice bran oil
Sea salt
Water
Tapioca dextrin
Ume brine (Ume plum, salt)
Mustard extract

Well, at least wasabi comes first, and it avoids using horseradish.

How Can You Tell if Wasabi Is Real?

If a restaurant is serving real wasabi, they'll usually tell you—and often show you. If it doesn't, and if the wasabi is not grated in front of you, it's likely coming out of a tube. Real wasabi is fibrous and will appear slightly gritty after grating. The color is a soft green, slightly fainter than a sage leaf. And one interesting tidbit, the color of the stem (sometimes referred to as a rhizome) is different when you compare the end of the stem closer to the roots (paler) compared to the tops (greener).

Fake wasabi often has a bright green color, almost fluorescent in appearance, due to the added food coloring. One version we tried out of a tube looked almost like apple sauce in color. And some of the fake stuff appears shiny. One interesting note about real wasabi is that there are more than 30 different varieties, and they can produce pastes of different colors. Orochi wasabi, for example, appears white when grated. Mazuma wasabi has a distinct purple ring or starburst pattern inside the stem, which produces a lavender or gray color when grated.

What Does Real Wasabi Taste Like?

The heat of real wasabi comes on quickly but also leaves fairly fast. Some people expect it to be two or three times hotter than imitation wasabi, but real wasabi has a much more complex flavor profile. Freshly harvested, the heat has an earthy quality. And there is a distinct, floral sweetness to the taste of real wasabi that imitation brands simply cannot replicate. When you purchase a full stem, you also get the fun of comparing the two ends. In addition to the difference in color noted above, the end closer to the root zone will have more heat, while the greener side has more sweetness.

The heat of fake wasabi is more overpowering, stays in your nostrils for a longer period of time, and can overwhelm the flavors of your sushi, steak, and other foods. It's more uniform in taste and does not have the complexity of real wasabi or the rich aftertaste. At the farmers market, we've had several customers say they don't like wasabi, only to try the real deal and change their mind. With only a few farms in the country, it's definitely a rare treat.

So now you know the key differences between real wasabi and the impostors. Real wasabi is the grated stem of the plant Wasabia japonica, typically served fresh and containing no added ingredients. Fake wasabi is a mixture of horseradish, mustard, starch, and green coloring, often containing little or no real wasabi. Horseradish and wasabi are both in the Brassicaceae family of plants, but their flavor profiles are distinctly different. And as noted above, if your wasabi is coming out of a tube, you're putting a bunch of other ingredients in your body. If you've never tried it, we highly recommend giving real wasabi a try.

Sources

The Washington Post: The wasabi sushi restaurants serve is pretty much never actual wasabi
https://www.washingtonpost.com/news/wonk/wp/2014/10/15/why-the-wasabi-sushi-restaurants-serve-is-almost-never-actual-wasabi/

Business Insider: Wasabi served at most sushi restaurants is not what you think it is
https://www.businessinsider.com/most-wasabi-served-in-the-us-is-fake-2017-1