Why decant? First and foremost, the purpose of decanting is to separate the sediment present in older reds from the remainder of the wine. A secondary reason for decanting is aeration, which has a complex array of effects on the wine depending on its style and age.
Aeration releases the gases, such as nitrogen or carbon dioxide, dissolved in young wines, allowing them to “open” and fully display their character. In very old wines, this will mean the already evolved bouquet will dissipate more quickly so it’s important to not leave a particularly mature wine exposed for too long.
Aeration can also help blow off “off-odours” such as sulphur dioxide in very young wines (both whites and reds) that have just been bottled or the musty, closed characters often found in older wines, an effect of reduction (the absence of oxygen).
So what wines should you decant? Old red wines, provided that they have been produced for cellaring purposes. Full-bodied older red wines based on Cabernet Sauvignon, Malbec, Petit Verdot, Shiraz, Tempranillo, Sangiovese, Carménère and other varieties will tend to develop sediment as they mature in the bottle. Although not fully understood by scientists even today, what is known is that the sediment is a combination of tannin and colour particles, which link with one another, forming chains and falling out of the liquid as the chains become too heavy. Decant older reds to separate them from this sediment and to blow off undesirable “closed” odours from the reductive effect of being in the bottle so long.
Young red wines, particularly full bodied styles intended for ageing, will also benefit from decanting. Here, sediment is not generally a consideration, however the aeration of the wine as it is being poured into the decanter and then into the glass releases the dissolved gases from within the wine, allowing it to “open” and fully display the wine’s character.
Young full-bodied oaked white wines, such as Chardonnay, often produced as cellaring styles, can be decanted. The aerating effect is much the same as for younger red wines, releasing the gases dissolved from the wine and also allowing some oxidation to occur, “developing” the wine once opened and hence displaying more and more complex fruit character. Young, light white wines, intended for early drinking will not generally benefit from decanting as their beauty is in the fresh primary fruit character which may be lost with aeration.
Decanting old white wines, even if full-bodied, oaked styles, is risky business as they will tend to oxidise very quickly and lose any fruit character they may otherwise have had.
How you decant a wine very much depends on the wine style and what you are trying to achieve. Younger wines that require aeration should be decanted quickly with a lot of movement. Don’t be afraid to energetically swirl the decanter prior to pouring the wine into the glass. Older wines that require the removal of sediment will need to be decanted very slowly and carefully.
1. Prior to decanting an older wine, stand the bottle upright until all the sediment has settled to the bottom of the bottle (may be several hours or days in advance).
2. Remove the cork or cap. 3.
Gently and evenly pour the contents of the bottle into the decanter. You should try to finish decanting in one smooth pour and the liquid should not ‘glug’ out of the bottle, nor should the bottle be tipped too far upside down, as this may disturb the sediment.
4. Pour the last part of the wine slowly to ensure that the sediment is caught at the shoulder of the bottle rather than flowing into the decanter.
5. Holding a light or a candle behind the bottle you are decanting may be useful in illuminating the contents of the bottle and allowing you to see the sediment.
6. When the sediment starts moving toward the neck of the bottle, stop decanting.
Written by Claire Tonon, Voyager Estate Sommelier