If you have ever eaten sushi, you know that bright green paste sitting on the side of your plate. One accidental bite can send a sharp, fiery rush straight up your nose. While most people think it is just there to add a spicy kick, the real reason wasabi is paired with sushi is centuries old—and it used to be a matter of survival.The inventionYears ago, long before refrigerators were invented, keeping raw fish fresh was incredibly difficult. Japanese chefs discovered that freshly grated wasabi acted as a natural shield against food poisoning. It contains a compound called allyl isothiocyanate, which fights off harmful bacteria. Originally, chefs tucked a smear of wasabi between the rice and the fish purely as a natural preservative to keep diners safe.Today, we have modern refrigeration, but wasabi stuck around because it makes sushi taste incredible. The sharp heat cuts right through the richness of fatty fish like salmon and tuna. It balances out the oils, tones down any heavy fishy aromas, and cleanses your palate between different pieces.

Love for wasabiSurprisingly, the green paste you usually get at local restaurants isn’t actually real wasabi. True wasabi comes from a rare plant called Eutrema japonicum, which only grows near cold mountain streams in Japan. Because it takes up to three years to mature and is incredibly expensive, most places use a clever imitation.The “fake” wasabi most of us eat is actually a mix of horseradish, mustard powder, and green food coloring. Since horseradish contains the same spicy compounds, it mimics the kick perfectly. However, real wasabi is much more delicate, slightly sweet, and smooth, whereas the imitation version hits you with a much harsher, more aggressive burn.

Tracing the history of wasabi:Wasabi has been part of Japanese history for thousands of years, with archaeological evidence showing people ate the wild mountain plant as early as 14,000 BC. Long before it ever touched a slice of sushi, ancient Japanese society used it strictly as a medicine to treat respiratory issues and digestive problems and to preserve wounds. Real cultivation began in the early 1600s when a villager in Shizuoka successfully grew it in a mountain spring and presented it to the shogun, Tokugawa Ieyasu. The shogun loved it so much—partly because the plant’s leaves resembled his family crest—that he declared it a highly guarded treasure, banning anyone else from growing it outside his territory. It wasn’t until the late 1700s and early 1800s, with the invention of modern, unfermented sushi in Tokyo, that wasabi officially stepped out of the medicine cabinet and onto the dining plate as a natural defense against food poisoning.