What are wine tasters looking for?

I notice that when my so-called ‘sophisticated wine friends’ taste wines they go through a whole fancy ritual, including holding the wine up to the light. Is this really necessary? Surely all modern wine is reasonably clear. What are they looking for? 
Lumps? Sediment? Goggas? 

Actually, that first examination is quite important. You can tell a whole lot about a wine simply by looking at it. It should be crystal clear, for example, and not turbid. And wines change their colour as they age. A red wine will start life a youthful purple and then gradually turn to garnet, brick red and finally to amber. 

A white wine will probably start with a greenish tint and then become gold and finally pale amber. So if you are tasting a young red wine and the colour is brick or brownish, you can expect to find a fault in it. The intensity of colour is also a useful indicator. A red wine that is dark and inky has probably been given a long period of skin contact—you can expect a powerful flavour, possibly with quite pronounced tannins. 

A wine that is more translucent will probably be lighter in character, and suitable for early drinking. Take a good look at your next glass of wine. You could learn a lot. It’s like walking round a car before you test-drive it.