|Tongue surface--in case you're|
The other four, of course, are sweet, sour, salty, and bitter.
Why is umami so elusive, so mysterious? Saxena says it's because you can't just add it like you can sugar, salt, vinegar, etc.
Umami is in MSG, which can be added--but it has fallen in disfavor.
Also people cannot describe this taste. The Japanese, in a taste test in one study, nailed it by name--but many of their staple ingredients--dashi, seaweed, bonito flakes--have a pure umami flavor.
"Deep dark meaty intensity"--The New Yorker.
"Yummy in a non-sweet, sour, bitter, or salty way"--NPR.
Around the turn of the 20th century, legendary chef Auguste Escoffier found that boiling bones in his veal stock gave it an intense flavor not like the others.
Others found this "taste" in asparagus, tomatoes, cheese, and meat.
Eventually they discovered that glutamic acid, when cooked, turns into L-glutamate, an amino acid we can taste.
I would say it provides "depth of flavor" as they say on the cooking shows. Sometimes they also say, "There is a lot of flavor going on there."
Maybe that means the fifth taste is in there.