Umami

The chemist Kikunae Ikeda of Tokyo Imperial University discovered umami in 1908. A simple dashi (出汁) made from kelp puzzled him. This stock lies at the heart of Japanese cooking. It tasted so satisfying, yet it was not sweet, salty, sour or bitter. Ikeda found the substance behind it: glutamate. He named the taste umami and patented monosodium glutamate (MSG) to deliver it. The company that went on to sell it, Ajinomoto, still has a name that means "essence of taste." For decades, Western science treated umami as a curiosity. Then, around 2000, researchers found special glutamate receptors on the tongue. Umami finally took its place as a real fifth taste.

Three substances create umami. Glutamate is in kelp (昆布, konbu), tomatoes and aged cheeses. Inosinate is in dried bonito flakes (鰹節, katsuobushi), meat and fish. Guanylate is in dried shiitake mushrooms. The magic is synergy. Combine a source of glutamate with a source of inosinate, and the umami you taste grows far beyond the sum of the two. That is the whole logic of dashi: kelp plus bonito. You can taste it at home with one of the simplest recipes in the world. Soak a strip of konbu in water and warm it. Take out the kelp before the water boils. Add a handful of bonito flakes, wait a minute and strain. The pale gold stock is the savoury backbone of miso soup and countless simmered dishes. The same trick works in kitchens everywhere: tomato and parmesan, ham and beans, mushrooms and meat.

In Japanese cooking, umami is less a trend than a philosophy. Traditional washoku (和食), which UNESCO recognised in 2013, relies on this deep savoury taste. It lets cooks season lightly, so each ingredient shows through instead of hiding under fat or heavy spice.