Japanese scientist Kikunae Ikeda first proposed umami as a basic taste — in addition to sweet, sour, salty and bitter — in the early 1900s. About eight decades later, the scientific community officially agreed with him....
So, basically, ammonium chloride tastes sour if I got this right. I would not classify this in the same league as sweet, sour, salt, bitter, and umami, as it is not a separate flavor, just a new molecule that bonds.
Compare this to the thousands of different molecules considered “bitter”.
A sixth basic taste may join sweet, salty, sour, bitter and umami on the tongue (dornsife.usc.edu)
Japanese scientist Kikunae Ikeda first proposed umami as a basic taste — in addition to sweet, sour, salty and bitter — in the early 1900s. About eight decades later, the scientific community officially agreed with him....