Bet you didn’t know that the fiery green paste that comes along with your sushi, what’s referred to as wasabi, is almost certainly not the real thing.

This imitation is probably a mix of mustard, horseradish and green coloring and not from the grated root of wasabia japonica, which grows indigenously in Japan and is farmed in a very select few places around the world — including Israel. 

Wasabi is one of the slowest and most challenging plants to grow, which also makes it expensive, according to Ronen. A kilo is sold for the equivalent of about $370 in the United States and is similarly priced in Israel.

Is it the real thing?

Ronen has some tips for knowing if what you are eating is real wasabi.

“It is not just something that hits you in the nose. It starts off sweet in your mouth and then goes up your nose. The heat then goes down to your stomach. It’s amazing.”

In Japan, Ronen explains, wasabi is used in many types of dishes including meat barbecues.

Making a paste with the correct taste requires the right timing and the right tools.

“In restaurants it should be prepared as a customer orders and then served within 15 to 20 minutes; otherwise it loses flavor. To get the true effect you have to grate it and the best way to do this is with shark skin, which feels like sandpaper,” Ronen explains.

“If this is done correctly the flavor will be unbelievable … if not, it will be like eating a spicy carrot.”