The fifth element
If you ask people how many flavours there are in food, they would usually come up with four: sweet, sour, bitter and salty (spiciness is actually a pain, believe it or not!). In the early 20th century, a Japanese scientist by the name of Kikunae Ikeda (池田菊苗) claimed that there's actually a fifth element in food: the umami flavour (うま味/鮮味). It's the deeply savoury, mouth-watering flavour that we associate with great savoury dishes. In a sense, is the flavour of flavour. It's distinct from plain saltiness, but a long-lasting 'flavourfulness' that literally make us salivate. By the way, research has shown that breast milk is the first taste of umami that humans encounter and is extremely rich in glutamates.
Interestingly, umami doesn't taste of anything on its own, but magnifies other savoury flavours and give a synergistic effect. Humans implicitly recognised this long ago and different cultures across the globe must have have been exploiting food rich in umami flavours since time immemorial. Foods rich in umami include fish, shellfish, cured meat (think bacon!) and certain vegetables (tomatoes and leek?). Fermented food, in particular, has long been used to give 'body' to savoury dishes. In East-Asian cooking soya sauce and fish sauce (nuoc nam) are absolutely indispensable, and they contribute depth of flavour to a dish in a way that salt cannot. Not to mention other Asian specialities like Korean kimchi, Japanese miso, etc!Compared to Asian cooking, it seems that western cooking employs less fermented stuff for seasoning. Sure, there's cheese, wine, bacon and all that, but they're not used as basic seasonings. Interestingly, people in ancient Greece and Rome did use a kind of fermented fish sauce (garum) in their cooking. For reasons unknown to me, its use gradually died out in western cooking. I think it's for this reason - the lack of a basic seasoning that's rich in umami - that classical French cuisine relies heavily on reduction for distilling flavours. Despite its great sophistication, it is extremely time-consuming too.
