What is umami? For starters, it's the mysterious element that made GQ's Alan Richman name Umami Burger the 2010 "Burger of the Year." It's the culinary magic found in seaweed, soy sauce and half of the Japanese dishes you've eaten at one time or another. You'll also find umami in tomatoes, potatoes, shiitake mushrooms, oysters, sardines, Parmesan cheese, steak sauce and cured ham. It's the cause of meaty mouthfeel and the active ingredient in MSG. Derived primarily from glutamate, a naturally occurring amino acid, umami is a flavor you can't get by combining any other flavors. Which means it's a primary flavor, like the four others you learned about in school: salt, sweet, sour and bitter. The idea that there was a fifth one nobody knew about was pretty radical -- like finding a sixth finger on your hand that you had never noticed before, or an additional member of ZZ Top.
Ozersky: Why Umami Shouldn't Go It Alone