Where to buy horseradish in Madrid

Wasabi - the German way?

Wasabi is an ingredient in sushi. (Stock.XCHNG / Rafael Fragoso)

Wasabi - the hot Japanese spice is becoming more and more popular - whether as an ingredient in sushi or as a coating for snacks. And since the term is used all sorts of jokes, the courts have already had to deal with it.

The District Court of Munich II recently prohibited a manufacturer from selling so-called wasabi peas that contain no wasabi at all. The provider defended himself by saying that the majority of Germans didn't know what wasabi anyway. And so nobody can be deceived. Anyone who thinks this argumentation is rather absurd should keep in mind that it comes from a delicatessen company whose international specialties are not exactly cheap.

In order to prevent such hair-splitting, we'd rather clarify what it is. Wasabi is a culinary luxury product in Japan - just like truffles in our country. It is a marsh plant, in the wild it only grows in cold, clear mountain streams. The roots are mainly used in the kitchen. It is similar to our horseradish, to which it is also related, by the way. It is much hotter than our horseradish, but tastes fresher and slightly sweet.

In Japan, wasabi is traditionally finely ground into a paste on a shark skin grater. The shark's skin contains many tiny teeth that act like a rasp. The active ingredients are released in the process. They are mustard oils, the chemist speaks of isothiocyanates. They have an antibacterial effect, which is why the spicy stuff is an ideal ingredient for specialties made from raw fish.

Since there are not enough suitable streams in mountainous Japan on which terraces can be built for cultivation, attempts were of course made to cultivate the plant industrially in the plains. That turned out to be quite difficult. The water must not be too deep, the flow rate must be correct, the temperature should not exceed 14 degrees, and of course the amount of light must also be precisely dosed, etc.

In the meantime, wasabi is no longer only specifically cultivated in Japan, but also in Korea, Australia, New Zealand and the USA. However, growing this demanding plant is anything but easy. Above all, hydroponic crops, as we know them from tomatoes, have proven their worth. The roots of the plants are in tubes filled with rock wool. The water then flows through there, and the fertilizer can be metered in very cleanly.

The plant is propagated mainly by cell culture. The inevitable large losses due to bacterial infections are then reflected in the price. Then you add hormones like gibberillins or benzyladenine. Curiously, the fertilization corresponds pretty closely to the requirements of greenhouse tomatoes. There is no mention of crop protection. But since wasabi belongs to the cabbage family, there are guaranteed to be numerous diseases and plenty of pests. The harvest takes place in the second year, about a month or two after flowering.

Defective products, especially black-discolored rhizomes, are not sold as fresh goods but are processed into powder or paste. And because nothing is allowed to go to waste in Japan either, the remaining parts of the plant, such as leaves, are always sausage. And probably there, too, goods are stretched with horseradish or mustard.

As a rule, you will look in vain for real wasabi on the German market. Most of the pastes are a mixture of horseradish that has been multiplied many times over with water and extenders such as starch, xanthan and lactose. Then there are sorbitol, rapeseed oil and acidulants. And don't forget the dyes tartrazine (E 102) and brilliant blue (E 133), which provide the typical green color. As always, the taste comes from the aromas

Those who prefer to eat something real can buy fresh horseradish from us. This is much cheaper than the delicatessen products. And if you freeze it deeply, you can also grate it wonderfully - and that without having pulled the fur over the ears of a shark beforehand. enjoy the meal!

District Court Munich II: judgment of November 18, 2009; Az 1HK O 4243/09
Miles C, Chadwick C: Growing wasabi in the Pacific Northwest. Washington State University Extension 2008
Tanaka I et al: Indoor cultivation of Japanese horseradish (Wasabia japonica Matsum.) Using artificial light. Shokubutsu Kankyo Kogaku 2009; 21: 175-178
Chadwick CI et al: The botany, uses and production of Wasabia japoinca (Miq.) (Cruciferae) Matsum. Economic Botany 1993; 47: 113-135
Rodriguez G, Punjy ZK: Vascular blackening of wasabi rhizomes caused by Pectobacterium cartovorum subsp. carotovorum. European Journal of Plant Pathology 2009; 124: 483-493
Park YY et al: Effect of salt strength, sucrose concentration and NH4 / NO3 ratio of medium on the shoot growth of Wasabia japonica in vitro culture. Journal of Plant Biotechnology 2007; 34: 263-269
Moon JS et al: Development of upland cultivation for production of marketable rhizomes in Wasabia japonica Matsum. Korean Journal of Medicinal Crop Science 2004; 12: 473-477