Samui Wining & Dining
What’s wasabi?

Some surprises are in store when it comes to this popular Japanese condiment!


22Cabbage, Brussels sprouts, mustard, wasabi, horseradish, broccoli. What do they all have in common? Yes, well, apart from the fact you can eat them? No guesses? All right then – they’re all related. They are brothers and sisters, all belonging to the brassicaceae family. And that’s a bit surprising, because although cabbages and Brussels sprouts look very much alike, the rest are a very diverse and mixed bag. The only other family similarities seem to be echoed between wasabi and horseradish, which appear similar to each other but look nothing at all like a cabbage! Wasabi and horseradish – keep this pair in your mind for a moment, as we’ll be coming back to them very shortly.

      And so to the thrust of this month’s culinary ramble, that all-time Japanese favourite, wasabi. In England, they have tomato ketchup and HP sauce to splash on their food. The Germans are as keen on mustard, and the Dutch wax poetic about mayonnaise. In Asia, they do things differently, however. Thai food comes with a strange little quartered basket of sugar, fish sauce, chillies in vinegar and ground chilli powder (just so as you know!). And the Japanese equivalent of all this is . . . half a table-full of condiments!

      Yes folks, the Japanese don’t really need to eat food at all; they could get by with just their sauces and pastes alone! There are dozens of them. They range from several strengths of varied vinegars, five categories of soy sauce, eight or more different sauce pastes and as many varieties again of toppings. Although, it has to be said, that’s in Japan. And it’s rare to come across such an extensive array of condiments in the Japanese takeaway at your local mall. But you can be sure that in any kind of Japanese restaurant, large or small, you will always see at least two basic staples. One of these is the familiar soy sauce. And the other is wasabi.

      Wasabi is something of a specialty. This ubiquitous green paste is made from a fiery-tasting root called ‘Wasabia Japonica’ and it’s not only the perfect accompaniment to raw fish, but it has been found to possess numerous health benefits, too. Right back as far as the 8th century this root was being lauded, and numerous Japanese manuscripts from this period (and later) refer to wasabi as an effective ‘medicinal herb’. For a long time this was in the province of herbalists, not cooks. But, in confirmation of its properties, recent studies have shown that the root contains elements that suppress a bacterium responsible for many stomach-related diseases, such as gastric inflammation and possibly even cancer. Because of this, wasabi became promoted as a means to prevent food poisoning, and this is why it emerged into the kitchen, and how it came to be associated with, and served alongside, raw fish.

     Unlike most other roots, the rhizome of the wasabi plant grows above ground and is a luminous bright green when mature, due to the chlorophyll produced by active photosynthesis. (The leaves, too, are similarly as colourful and equally as edible.) The root is finely ground, traditionally by using a grater made of rough sharkskin. After grating, the pile is left for several minutes to allow the wasabi’s flavour to develop; the flavour-producing compounds emerge following grating and exposure to air. But here’s the catch. This mix is extremely volatile. Meaning that the flavour and the ‘hot’ taste quickly begins to diminish.

      It must be eaten freshly grated! And this is the reason that sushi chefs will usually place the wasabi between the fish and the rice before serving, because covering wasabi in this way preserves its flavour for a little while longer. It’s hot but doesn’t have a lingering, burning aftertaste. It tastes smoother, cleaner and earthier than other substitutes. Wasabi’s ‘heat’ is not oil-based like chillies, and is easily washed away by more food and drink. The sensation of its heat is felt more at the back of the throat and in the nasal passages than the mouth, however, and can be quite painful, depending on the amount consumed!

         But all of this comes at a price. The genuine Wasabia Japonica is difficult to cultivate, prone to pests and crop failure, and expensive to buy – not to mention that its table life is very short, although it is (expensively) possible to refrigerate the roots for a short while. In other words, it’s rare and expensive and the paste does not preserve well in tins or jars. And because of this, I’ll make you a bet. I bet that you have never actually eaten wasabi, even though you thought that you had. Even in many of the restaurants in Japan, real wasabi is just too expensive to use (and the demand far exceeds the supply). Certainly, for most of the Japanese restaurants in other countries this holds true. What you’ve actually been eating is a mixture of grated horseradish plus green colouring, and probably some starch, plus a little mustard included for ‘bite’.

         I told you to keep wasabi and horse radish in your mind! And this is the reason why. The genuine wasabi roots can be packed and refrigerated, allowing an extended life of around two weeks or so. But how many restaurants can afford this? So the probability is that you’ve been enthusing over horseradish, not wasabi, for all these years! In a side-by-side comparison, the horseradish paste that’s served in the majority of restaurants outside Japan is harsher than, and not as fresh-tasting, as the real thing. And it doesn’t have that lingering, burning aftertaste, either. But, as they say, you can’t miss what you’ve never had. And if you now find yourself in a Japanese restaurant and musing, “what’s wasabi?”, I’m afraid there’s just no answer to that one!


Rob De Wet


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