It may come to you as a surprise, but the green paste you've been eating with your sushi isn't wasabi. In fact, most pastes have trace amounts of real wasabi. If you were to check the ingredients, you'd find that it's mostly horseradish, a sweetener, salt and a bunch of other ingredients and maybe up to 1% of actual wasabi. Maybe, since some pastes don't contain wasabi at all.

So why is there so little wasabi in wasabi paste?

The answer is simple – its cost. Real wasabi is hard to come across and it can cost hundreds of dollars per kilo. Even though it's related to horseradish, horseradish requires nowhere near as much effort to cultivate.

In fact, wasabi is considered to be the hardest plant to grow commercially.

But why is wasabi so hard to grow?

Wasabi needs a constant supply of running spring water, it likes a shady area and rocky soil, or gravel. It can only tolerate a temperature of around 8-20°C all year round.

Too much humidity or wrong mineral composition of the soil can cause all sorts of problems for the plant. On the other hand, too much exposure to light can easily damage the plant.

Where is real wasabi grown?

The only place where wasabi grows naturally is alongside Japanese mountain streams, where it has the very specific conditions it needs to thrive.

It wasn't until several years ago that wasabi was grown exclusively in Japan. Nowadays, we're seeing more and more farms dedicated to growing wasabi in other parts of the world.

How long does it take to grow real wasabi?

As if growing wasabi wasn't hard enough, it takes on average a whopping 18 months before wasabi can be harvested. Harvesting wasabi is also a manual process and fresh wasabi cannot be held for too long or stock-piled.

Summary

Hopefully, it now makes sense why fresh wasabi is so expensive. Unlike the commonly found "wasabi paste", real wasabi is very rich in flavour. If you'd like to learn more about wasabi, please check out some of our other articles.