Wasabi

Wasabi (Wasabia japonica) is root plant that grows naturally along stream beds in mountain river valleys in Japan and also in fields or near water in other cool climates. The root is harvested when it reaches a length of 10-15 cm (4-6 inches) and is used make one of the most popular seasonings in Japanese cuisine, referred to as wasabi or Japanese horseradish. Those plants grown in or near water (known as aquatic or semi-aquatic wasabi) produce a much higher quality product than those that are grown in fields (oka wasabi).

Fresh Wasabi Root

Fresh wasabi root is usually only sold in Japan. It should be uniform in colour, unblemished and firm to the touch. It is prepared by removing the leaves and stems and then by washing the root well to remove any dirt. The leaves may be set aside to use in salads or as a garnish. The root may then be grated in a circular motion using a very fine grater (preferably a sharkskin grater), so that the pieces fall into and form a small pile. The grated root should then be left to warm to room temperature so that its sweet and spicy hot flavour may develop. However, the grated root should not be left for too long as its flavour will start to diminish after about half an hour.

Wasabi Paste and Powder

As fresh wasabi is not often available outside Japan, it may be sold in tubes as a paste or it may be ground into a powder that can be mixed with water to produce the thick, spicy paste. However, the majority of powdered versions usually contain little of the wasabi root, although they may contain wasabi leaves. This imitation wasabi (also sold in paste form and labelled as 'prepared wasabi') is usually made from horseradish, mustard, and green food colouring and is used extensively in restaurants and sushi bars as a cheap alternative to the relatively expensive real product. When buying wasabi paste, look for tubes labelled '100% real wasabi' or 'hon-wasabi' (true wasabi) to get the authentic wasabi root product. If in doubt, check the list of ingredients on the product label.

Using Wasabi

Wasabi is used to make a pungent and eye-watering condiment that is most commonly served with sushi or sashimi dishes as well as for adding to cooked fish, soups and salad dressings. It is a common flavouring for dim sum and for soba and udon noodle dishes, and may also be used to make sauces, dips or marinades. It may be blended with other ingredients such as rice wine or soy sauce (creating wasabi-joyu) for extra flavour.

Wasabi has an intense hot taste, which soon ebbs to leave a sweet and mildly spicy flavour. Its heat is more similar to that of a hot mustard or horseradish than a chilli pepper, producing vapours that burn the sinus cavity rather than the tongue. It should be used sparingly in all dishes.

Storing Wasabi

Fresh wasabi may be kept in the fridge for up to a month, wrapped in a damp paper towel. It should be washed every week. Wasabi paste can be kept in a cool, dark place. Once opened, it may be stored in the fridge or freezer for up to a year.