Not only does MSG give dishes a savory, umami taste, but it is considered to be the purest form of umami. Why is that? And what does it even mean?
First, let’s explore what umami is. Umami, the taste of savory, is one of the five basic tastes. It signals that a dish contains protein. When glutamate, an amino acid that is part of many proteins, comes in contact with the sensory cells on our tongue (our “taste buds”), those cells send a signal to the brain that says “what you’re eating is savory.” Glutamate is found naturally in many foods (cheese, soy sauce, many vegetables, etc.), but it is always present with other flavors. For example, a slice of prosciutto tastes savory, but it also tastes salty. A ripe tomato tastes sweet and savory. Broccoli tastes bitter and savory.
There is one time, however, where glutamate is found alone, and that is in MSG (monosodium glutamate). Well, it is almost alone; there is a little sodium mixed with the glutamate for stability, but it does not add much flavor. Because the glutamate is alone, when MSG is eaten, it triggers only one taste sensation – umami. This isolation of the savory flavor makes it the purest taste of umami. This phenomenon is much like salt and saltiness. Plenty of foods taste salty, but licking salt gives you the purest taste of saltiness.
You can try this for yourself by putting a pinch of MSG on your tongue. The first time I did it, I braced myself for something strange, but ended up exclaiming, “Oh! So that’s what that taste is!” It is similar to sipping a little meat broth, but what you are really tasting is the purest taste of umami.