Umami Day

What Is Umami Day?

Every July 25th is also "Umami Day" (うま味調味料の日, Umami Chōmiryō no Hi) in Japan. On July 25, 1908, Dr. Ikeda Kikunae (池田菊苗, 1864–1936) of Tokyo Imperial University (now the University of Tokyo) announced his discovery of a fifth basic taste — distinct from sweet, sour, salty, and bitter — which he named "umami" (旨味, meaning "delicious taste" or "savory taste"). Ikeda identified glutamic acid (グルタミン酸) as the compound responsible for the umami taste in kombu seaweed (昆布), and subsequently developed monosodium glutamate (MSG, グルタミン酸ナトリウム) as a commercial seasoning.

The Discovery of Umami

Dr. Ikeda's discovery came from a deceptively simple observation: the dashi broth made from kombu seaweed had a distinctive savory quality that could not be explained by the four recognized basic tastes. By extracting and analyzing kombu's chemical components, he identified glutamic acid as the responsible compound — a 20-carbon amino acid that triggers specific taste receptor responses producing the savory, mouth-filling quality he named "umami." His 1908 paper describing the discovery and the development of MSG as its commercial embodiment was a landmark in both food science and the global seasoning industry.

Umami in Japanese Cuisine

Umami is the fifth pillar of Japanese cuisine — the quality that makes dashi (出汁) broth, miso, soy sauce, fermented fish products (like katsuobushi), and aged cheeses and meats so deeply satisfying. Japanese cuisine was built around umami long before Ikeda named it — the careful combination of kombu (rich in glutamate) and katsuobushi (rich in inosinate) to make dashi is a synergistic umami combination that has been practiced for centuries. Ikeda's discovery gave scientific language to what Japanese cooks had known intuitively for generations.

MSG: Controversy and Rehabilitation

Ikeda's discovery led to the commercial production of MSG by the Ajinomoto company (founded 1909), which became the world's largest food seasoning company. MSG was used globally until it became the subject of unfounded health concerns (the "Chinese Restaurant Syndrome" scare of the 1960s-70s, now thoroughly debunked by scientific research). Contemporary food science has fully rehabilitated MSG's safety and confirmed that the umami taste it provides is a genuine and important dimension of human flavor perception.

Fun Facts

• Ajinomoto: The Ajinomoto company (味の素) — founded to commercialize Dr. Ikeda's MSG discovery — became one of Japan's largest food companies and a global producer of amino acids, umami seasonings, and processed foods. The brand name "Ajinomoto" (味の素, "essence of flavor") became so closely identified with MSG in Japan that "ajinomoto" is used as a common noun for MSG throughout Southeast Asia.
• Umami receptors: Scientific confirmation that humans possess specific taste receptors (T1R1/T1R3) that respond to glutamate — providing the neurological basis for umami as a genuine basic taste distinct from the other four — came in 2002, confirming Ikeda's 1908 discovery with molecular biology.