There are two reasons for why we decant wines...decant older wines to separate it from its sediment, and decant younger wines to increase oxygenation, reveal more complexity and open up aromas and flavors.
To fully enjoy young wines (up to 10 years red and white) consider opening them 8 to 12 hours prior to consumption for oxidization or decant the wine, as this shortens the aeration process.
The main preserving element in wine is carbon dioxide which becomes part of the wine during the first (alcoholic) fermentation. Decanting diminishes the amount of carbon dioxide and "matures " the wine, allowing the bouquet to develop faster. On the pallet, decanted wine expresses higher levels of fruit in red wines and it tends to integrate and smooth out tannins.
When decanting young wines, turn the bottle directly into the decanter and let it splash into the vessel to promote oxygenation.
When decanting off the sediment of an old wine, slowly pour the wine into the decanter without allowing any sediment to leave the bottle.
Wondering about decanting? Try the following exercise:
Using identical glasses, decant half the bottle and serve the other half directly from the bottle -- then draw your own conclusion.
