Spitting is frowned upon in polite society － unless the spitter is engaged in tasting wines.
Experts would first stick their noses into a glass of wine: it is important to get a good whiff before tasting the wine.
Once in the mouth, the wine is swirled around － or chewed － for a few seconds. The taster may then make a "duck face" to allow a bit of air in to detect further characteristics. Next, the mouthful of liquid is spewed back out in an unapologetic burst into a spittoon.
For professionals － winegrowers, oenologists, sommeliers, wine merchants － tasting wine means assessing its appearance, its interaction with air, its aromas and its taste, as well as its "structure" in the mouth.
People think swallowing the wine will give you more aromas, but that’s false. The aromas often come after the spitting. When the wine mixes with air coming from the nose, spitting can bring out other prevalent aromatic notes, a phenomenon called "retro-olfaction." (AFP)