Investing in a decanter can provide a great way to serve wine. Ultimately, a decanter is designed to serve two purposes:
- Removing Sediments
Decanting a wine is removing the sediment which accumulates in a bottle by leaving it in the decanter - the receptacle separating it when poured.
Red wines typically produce more sediment than their white counterparts. In fact, it's very rare that you'll ever find sediment drifting in a white, lessening the need for a decanter. With reds however, it's a different story.
From the moment a red is bottled, and sometimes even before that, it begins to develop sediment - colour pigments, dead yeast cells, and parts of grapes and seeds, especially if the bottle has sat for a considerable amount of time, which it may have done if kept in wine storage.
Although some wine enthusiasts don't mind seeing the sediment of a well-aged wine in their glass, most don't enjoy the bitter dusty taste and so etiquette says that young or aged wine with sediment deposits should be decanted.
Pouring wine into a decanter brings it into contact with air, starting the process of aeration and bringing the lurking aromas and flavours to the fore.
As soon as the liquid comes in contact with air, it oxidises; in other words it undergoes a speedy ageing process, with tannins and acidity softening to create a more harmonious and flavoursome wine. The fact that acidity subsides with oxidation means that whites wine too stand to benefit from breathing; this is a little known fact.
There are no hard and fast rules when it comes to decanting wines for the purposes of aerating, but the general consensus is that most wines benefit from at least 30 minutes to an hour of decanting.
The better that you know a wine, the more likely you are to know of its characteristics and how long it should ideally be exposed to oxygen. Some can last for veritable hours and improve on a number of accounts, particularly young wines with high acidity or tannins.
You may even find big reds which truly only reveal themselves after 4-5 hours. Other wines, particularly older and more frail wines, can fall apart after as little as 15 minutes of exposure to air.
Experimentation is key, but for very old wines, it is best to focus on decanting sediment and limiting aerating to less than 15 minutes if you are unsure of the condition of the wine and in which conditions it was stored and cellared!