Without our sense of smell , we are unable to appreciate food or distinguish between easily. When chewing, the vapors travel from the back of our mouth, up what is called the retro-nasal passage, to the same sensory organs. Authors usually start by giving their readers detailed exposition of what the sense of sight can reveal about a wine. The wine society however is here to indulge in the joys of consumption and not to simply admire the visual pleasure of a glass of Claret . The eye does neverhtless have an important role to play even for the pleasure drinker, anticipating a fault.
Hazy wine indicates some kind of malady and suggests an uncharacteristic taste is likely.
If the wine is browner that one would normally expect, then the wine is probably oxidized. This is due to back storage or an inferior cork. An unexpected sparkle will make the wine worse than it should. The wine may be going through an unintentional secondary fermentation in the bottles. Wine crystals are quite harmless and also quite rare.