Why are some wines “decanted”, and what do people mean when they say that a wine needs to “breathe”?

It is quite common to hear wine people speak about wines needing to “breathe”. By breathing we actually mean aerating, or oxygenating. This entails introducing air to the wine to help it “open up” – a common practice for powerful, young, highly concentrated and tannic red wines. Opening up is almost a kind of mini-maturation process. Depending on the wine, we would expect the breathing process to enhance the aromas of the wine and/or soften an especially youthful or tannic wine. A proper aeration of wine entails decanting the product – basically, pouring the wine from the bottle into another receptacle. We would not get an adequate aerating if we were to only remove the cork from the bottle, because far too little of the wine would be in direct contact with the air. By pouring the wine into another vessel we introduce all of the liquid to oxygen, and inevitably increase the surface area of the liquid in contact with oxygen. I am an advocate of decanting certain wines, but not all! I have seen the benefits of decanting certain reds in terms of an increased aroma and flavour profile, but it is also true that by decanting older, more delicate wines that the already miniscule aromas and flavours may dissipate.

The second reason that a wine may be decanted is to separate the liquid from any sediment that may have formed in the bottle. Sediment is a very natural occurrence in many red wines. As early as three years old, or more commonly in the 5-6 year range, many red wines will begin to form small solid particles – basically the combination of things like tannin and colour pigments coming together. While these particles (sediment) are harmless to humans, they are unsightly and don’t taste particularly pleasant. When decanting for the purpose of separating liquid (wine) from solid (sediment) it is beneficial to stand the bottle upright for a period of 24-48 hours prior. This allows the sediment to collect at the bottom of the bottle. Once the sediment is settled at the base, we need a candle or a flashlight to shine up through the neck of the bottle as we slowly pour the liquid into the decanter. By pouring very slowly and steadily we will be able to see when the sediment reaches the neck of the bottle, and then stop pouring – leaving a small amount of wine and hopefully all of the sediment in the near empty bottle. This type of decanting is beneficial for many older red wines and ports, as these are the wines that usually cast sediment.

While we decant slowly and steadily to separate wine from sediment, we perform a much different type of decanting when we aerate, or let the wine “breathe”. Since the wines we decant to aerate are usually quite young and normally don’t have sediment, we can perform what is known as a vigorous decant. In this case we can turn the opened bottle completely upside down and let the wine flow into the decanter at maximum speed. This further exposes the liquid to the oxygen, increasing any softening or aromatic benefits experienced during this practice. In terms of the much asked question, “should white wines be decanted?” the answer is usually “No”. Certain white wines such young Meursault or Chablis from France may benefit, as they are meant to age, but most whites are meant to be drunk in their youth when they are fresh and vibrant, so decanting would offer little to no benefit!

As an experiment it would be interesting to test two bottles of the exact same red wine – one opened and decanted much earlier, and one just opened and poured without the benefits of decanting. Depending on the wine, I guarantee that the decanted product would be softer and more approachable than the bottle just opened and poured.