A perennial plant and a member of the Brassicaceae family – similar to cabbage, horseradish and mustard – wasabi is a semi-aquatic herb that is grown in Japan, Tasmania, Hawaii and Oregon. Planting and harvesting usually occur at the same time of year – either in autumn or spring, when the temperature is cool and moisture is high. This difficult to cultivate plant grows naturally along riverbeds in mountain valleys in Japan and is harvested all year round. The plant is grown mostly for its underground rhizome (tuber), but its above-ground leaves are also edible. A mature wasabi root usually reaches peak harvest size in its second year of growth, resulting in a firm, cylindrical stem.

This brown and green-skinned stem can then be turned into a strongly flavoured paste using a special grater. This fresh paste is known to stimulate the nasal passages and contains a hotness more akin to a hot mustard than chilli. When grated fresh into a paste, wasabi can lose its flavour within 15 minutes if left uncovered. Therefore, sushi chefs usually tuck wasabi between fish and rice to preserve the strength.

Because of the difficulty in harvesting this Japanese stem, horseradish is often used as a replacement, mixed with mustard, starch and green food colouring to imitate the powerful plant. This has resulted in horseradish being known as ‘Western wasabi’ in Japanese, and in English, wasabi known as ‘Japanese horseradish’.

You can also find wasabi available in a dried powder, or if you come across the leaves, you can eat these fresh – delivering a hit of the same spicy flavour. Daio Wasabi Farm near Matsumoto is one of Japan’s largest wasabi farms and produces a range of products including wasabi paste, ice-cream, soba noodles, beer, juice and chocolate. In Australia, Shima Wasabi is an Australian owned and operated company that has been producing 100% pure authentic Japanese wasabi for more than 12 years. The pristine waters and climate of Tasmania make for perfect growing conditions, with the farm using climate-controlled greenhouses and a unique hydroponic production system to produce fresh wasabi all year round. Shima then provides restaurants around the country with fresh wasabi, as well as producing a pure wasabi powder, which you can find locally at Genki Mart in Alderley.

If you come across the root and grate your own, add a smear on top of your sushi or sashimi for a touch of tradition, or spice up a salad dressing, bowl of mashed potato or a bloody mary for something a little different. You can also turn down the heat by making wasabi hollandaise and mayonnaise, and snack on crunchy legumes or peas coated in wasabi dust.