The sense of smell is so complex that still do not know how it works in all its breadth. There are two senses: one is the orthonasal and the other the retroolfaction.
The orthonasal is the external olfactory sense, which occurs by breathing, and allows us to detect odors in our environment. The retroolfaction olfaction is an internal sense, which occurs when breathing out, enabling us to perceive the qualities of what we have eaten, as explained on www.xakataciencia.com. In general are the scents that are perceived when tasting a wine and leave some wine in his mouth and sucking, mixes the wine with oxygen taking air through the mouth, you generate a bubbled and aromas rise on the back of the mouth coming to nose.
The orthonasal olfaction procures pleasure of anticipation. The retroolfaction is the reward.
At the olfactory analysis will approach the glass to your nose. We will measure its aromatic intensity. Then, we smell after shaking the cup, noticing if there is variation in the perceived odor before and at the same time, identify the aromas. Shaking, got wine aeration and a celebration of spices.