What is the difference between hon-wasabi and Western horseradish? How to pick a tube that still has scent

You pick up a tube of wasabi at the supermarket. Look closely at the label and you notice that the wording splits: some say "hon-wasabi iri" (本わさび入り) and others "hon-wasabi shiyo" (本わさび使用).

The fact is that most tube wasabi on the shelf is built mainly from Western horseradish. Much of what we take for the taste of wasabi is the heat of a plant other than wasabi itself.

Hon-wasabi and Western horseradish: different plants to begin with

Hon-wasabi (本わさび) is a plant of the genus Eutrema, in the Brassicaceae family. The form held to be finest is "sawa wasabi," grown in clean running water, and Shizuoka, with the spring water of Fuji and the Abe River, is one of its noted districts.

Western horseradish, widely used in tubes, is a field crop in a different genus. Its heat is sharp and strong, but the clean scent and faint sweetness that hon-wasabi leaves after the burn clears the nose are said to be muted. Because it can be secured cheaply and in quantity, it has long been valuable as the main ingredient in processed products.

Scent and sweetness: what hon-wasabi leaves behind

What hon-wasabi is really good for is not the heat itself but what arrives after it: the scent and the sweetness.

The sharp heat clears the nose, and a green scent and a soft sweetness stay in the mouth. Whether that finish is there or not is the main line between hon-wasabi and Western horseradish. Beside sashimi, sushi or cold soba, what lifts the ingredient instead of covering it is exactly this fine scent.

Tamaruya Honten's Mizuaoi: the green of Shizuoka in a tube

Tamaruya Honten, which hung out its curtain in Shizuoka in the early years of the Meiji era, is a long-established house known for its wasabizuke.

Its top line, "Mizuaoi" (瑞葵), is a tube wasabi made with hon-wasabi grown in Shizuoka Prefecture. Behind the heat that clears the nose you can taste the scent and faint sweetness only hon-wasabi gives, and the finish is nothing like that of a mainly-horseradish tube. Getting that scent out of a tube is what a higher line, particular about district and ingredient, is for.

What to look for, and how to use it

• Choose tubes where "hon-wasabi" comes first in the ingredients and the proportion is high
• Beside sashimi, sushi or cold soba, when you want the ingredient's own scent to come up
• Also good with roast beef, with steak, and with ochazuke
• Heat drives the scent off, so add it at the finish or just before eating

Lay a line of hon-wasabi across your usual plate. Once the sharp heat has cleared, scent and a faint sweetness stay behind.

Frequently asked questions

What is the difference between hon-wasabi and Western horseradish?

Hon-wasabi is a plant of the genus Eutrema in the Brassicaceae family, and the best-known form is "sawa wasabi," grown in running spring water. Western horseradish is a field crop in a different genus; its heat is strong, but the clean scent and faint sweetness of hon-wasabi are said to be muted in it. A good many tubes on the shelf are mainly Western horseradish, for reasons of cost.

Can you get real hon-wasabi in a tube?

You can. As a rough guide, look for tubes where "hon-wasabi" appears first in the ingredients and makes up a high proportion. Higher lines that use hon-wasabi grown in Shizuoka Prefecture, such as Tamaruya Honten's "Mizuaoi," let you taste scent and sweetness behind the sharp heat.

When should wasabi be added?

The scent goes off easily with heat, so it is best added at the finish or just before eating. Beyond sashimi and soba, it goes well with roast beef and with ochazuke.