Given there are typically two reasons for decanting there are also two basic styles of decanting. For lack of more eloquent terminology these styles are known as the ‘hard decant’ and the ‘soft decant’. Many people are familiar with the soft decant, but it is important to understand the hard decant as you will probably use it more often. The hard decant is most often used for big, young red wines to open up the aromas and flavors. This type of decanting requires little vigilance as all you need to do is open the bottle and pour it down the mouth of the decanter exposing the wine to the maximum amount of air on its way down. There is no need to be gentle because when all the wine has been transferred to the decanter you are going to shake the wine vigorously around the bowl of the decanter to release the carbon dioxide trapped in the wine and to expose it to more oxygen. Some sommeliers will even shake the bottle vigorously before turning it upside down into the decanter. Let the wine sit for about 15 minutes and the flavors should be enhanced from the exposure to air. You may want to sneak a taste of the wine before decanting it so that you can experience the effect firsthand.
The soft decant is ideal for older red wines that contain sediment, the deposit that accumulates in the bottle during the ageing process. The sediment is not harmful — in fact Madame Leroy of the famed Domaine Leroy in Burgundy proclaims the sediment the best part and professes to keep it for herself. Most people find it unpleasant to drink, however, and that is where the soft decant comes in. This requires some preparation, good lighting and a steady hand. First, let the bottle stand upright for at least an hour (better to have it stand for an entire day or two) to let the sediment drop to the bottom of the bottle. After this has happened, open the bottle, turn it sideways and pour the wine slowly into the decanter while watching the neck of the bottle carefully for sediment. Once the sediment has been successfully separated from the wine, give the wine a couple of minutes to settle in the decanter before pouring into glasses and enjoying.
There are some wines you don’t want to decant at all. Very old, fragile wines (such as old Red Burgundy which is made from the Pinot Nor grape) that are holding on to their fruit for dear life will only fall apart more quickly if exposed to air. If you have any specific questions about decanting, feel free to comment and we'll get back to you.