Wasabi – The root of the Eutrema wasabi plant native to Japan is frequently called Japanese horseradish even though the two plants are not related. In Japan the root is available fresh and is often grated and added to fish dishes, but the rest of the world has to be content with powdered wasabi, or with powdered wasabi that has been prepared in a paste.
In its dry, powdered form wasabi has little taste and only develops its eye-tearing and sinus-clearing pungency when mixed with water. It loses its flavour when exposed to heat, so is typically served with and added to cold foods. It is essential to sashimi and sushi. When buying powdered wasabi, read the label carefully. Many so-called “wasabi” products actually contain horseradish, mustard, and food colouring because wasabi is expensive to grow due to its finicky horticultural requirements. The real thing should cost at least twice as much as the imitation. Powdered wasabi has a shelf life of several months, and the prepared paste will last almost as long if properly stored.