We've all just been eating water, horseradish and green colouring

Wasabi found in most restaurants isn’t actually real wasabi.

Most of the time, the green paste which is served as wasabi is actually just a mixture of water, mashed horseradish and green food colouring, with a trace amount of wasabi plant.

A high-street chain told the Independent that their wasabi sachets only contain 0.6% of the Wasabia Japonica plant, which is what traditional wasabi is made from.

The explanation behind this is a practical one. The Wasabia Japonica plant is regarded as one of the hardest plants to grow. The plant requires lukewarm spring water and a specific amount of light and shade. The plant also needs to spend 18 months in the ground for perfect growth.

Additionally, real wasabi quickly loses its flavour and is best served within five minutes. As a result, even high-end chefs tend to layer up the wasabi between rice and fish to prevent if from losing its pungency.

Shark-skin graters are used in Japan to grind the plant’s stem instead of its root to release its strong flavour.

Consequently, the wasabi that is served worldwide is vastly different to the Japanese original.

Next time your self-claimed sushi loving hipster friend takes you to their favourite ‘authentic’ Japanese restaurant, you’ll know exactly what to say.

Wasabi crop growing on Japan's Izu peninsula

Wasabi crop growing on Japan’s Izu peninsula