Take your first sips of a wine and your palate will experience a cascade of taste sensations. However, there are other senses involved too, and the tasting process unfolds in a number of steps that make up the global flavour of wine.
The mouth is a multisensory organ that contains the tongue, with its taste buds. The smells pass through to the throat towards the nose. Also, the mouth can distinguish temperatures, as well as alcohol content in wine.
The first thing you should know is that taste and gustation are different concepts. Gustation is the faculty of taste that belongs to the mouth, whereas taste is the simultaneous combination of multiple senses, basically, gustation and olfaction.
When you take a sip of wine, the many flavours come one after the other in almost identical sequence. First, you detect sweet, then acid and finally, sour. Moreover, they disappear in reverse sequence.
This is the reason why wine tasting must follow a series of steps:
1-Attack: It is the first impression you get on the tongue. You will feel the sweet and the sour in the wine. This stage lasts two or three seconds. The sweet components and alcohol are the primary substances here.
2-Evolution: In this phase, which lasts five to ten seconds, you can taste savoury and bitter flavours. The sweetness in the wine fades.
3-Aftertaste: At this point, you will perceive the aftereffects of the wine in the mouth – pseudo-tactile and indirect aromatic sensations that get to the nose when you swallow the wine.
4-End phase: In general, it produces aromatic sensations only derived from retronasal olfaction. It comes after swallowing the wine. It is the second impression of the aromas left by the wine when the odour molecules dissolve in the mucosa. It lasts from eight to twelve seconds.
So, when we talk about aftertaste and retronasal or second smell, we are talking about the impression left in the throat and the nose after you swallow the wine.
To conclude, the taste of a wine is the impression it makes on the mouth, while the aftertaste is the taste that lingers in your mouth. It is important, then, that you learn to distinguish the mixture of flavours that develop when you sip a wine as well as its aftereffects in the mouth and the nose.