system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is "umami" and how do you recognise it when tasting food?
gpt
Meat (and a few other things) contains an amino acid called "glutamic acid".  You've heard of the synthetic/isolated version of this, MSG.  Umami = MSG.

It has a sort of subtle flavor, in that if you put a pinch of MSG on your tongue, it won't taste *good* (you'll taste it, but it just doesn't taste "right" by itself).  If, however, you add that same pinch to your dinner (any dinner, doesn't matter what), *BAM*, suddenly you have the best Kraft Macaroni and Cheese *ever*.

Opinions vary about whether or not it actually counts as bad for you.  IMO, this falls into the same category as gluten, where you have a tiny minority of people truly sensitive to it, and millions of people terrified of something completely harmless.