‘Umami’s not what you think it is. It’s translated as “savoriness”, but that’s usually misinterpreted as a kind of general descriptor, the way food could be called “filling” or “chewy”. It’s also got a sense of being this subtle and higher-order property of good cooking, brought to us from the mysterious East.
Umami is a molecule. Well, actually a class of molecules that hit mGluR1 receptors (among others) in your mouth so that you get a meaty, savory taste. And it’s not only appreciated by the discerning Japanese, but also by the somewhat less discerning hamsters. It’s a basic taste in the same way the other four are: The particular ingredient has been identified in food and the taste receptor has been identified in your mouth. Some don’t believe in umami, but you still experience it unless you are missing the receptors for some reason, which would constitute a minor disability.
The most significant umami compounds are glutamates, which are the salts of glutamic acid, and in practically everything you enjoy as savory. Most cultures have created a glutamate-rich cooking ingredient that seems absolutely disgusting without an additional “this has glutamates” explanation. These include decomposing fish (anchovies, Worcestershire sauce, fish sauce), decomposing beans (soy sauce, miso), decomposing milk (cheese), and leftover beer-goo….’
— Jehan via Atoms vs Bits