ONE hypothesis is that decanting can improve the drinking quality of certain wines prior to pouring it into a glass. Actually, my first attempt at it – as a student, decades ago – had quite the opposite effect.

Determined to impress his parents with an elegantly adult dinner, a boyfriend and I de-boxed a five-litre Nouveau-du-Nampak into a glass carafe, which he rummaged from the murky depths of a cupboard somewhere in the ramshackle digs that he shared with five other domestically disabled youths. In our over-enthusiastic ignorance, we omitted to properly rinse the vessel. We thus discovered – as his father violently spewed a bursting mouthful of the mucky red liquid onto his wife’s pale pink cashmere-covered bosom – that the decanter had previously contained salad dressing.

While decanting – not to mention unintentionally blending it with vinegar, olive oil, garlic and the dregs of other miscellaneous herbs and seasoning – did nothing to improve said Nouveau-du-Nampak, there is strong support for the practice among wine fundis. This, despite the argument presented by other equally knowledgeable parties that there is no definitive evidence that decanting is actually effectual or helpful. So the question begs: To decant or not to decant?

The process of pouring wine out of its bottle into another container originally came about in the quest to separate wine from any sediment that may have developed in the bottle during maturation. In the past, prior to the perfection of the process of clarification, this was considered more or less essential. Properly decanted, wine sediment remains in the bottle. This ostensibly helps prevent the occurrence of any dark, unappealing lurgies in your glass, which can taste bitter. (Even this is somewhat contentious: There are those who argue that some fine lees (more delicate sediment) in a glass of wine can add to its complexity and improve its taste.)

These days, with effective filtration processes in place, wine is largely decanted to “promote aeration”, “open it up” and “release the aromas”.

“There are no hard and fast rules for decanting, but I believe that young, robust and tannic wines benefit the most from decanting,” says cellarmaster for Rustenberg Wines and one of the Cape Winemakers Guild’s newest members, Adi Badenhorst. “When the wine comes into contact with oxygen, the aromas present are freed up and provide greater drinking pleasure. I always decant fuller, young red wines and some whites too, particularly wooded varietals.”

Quoin Rock’s Carl van der Merwe concurs: “Although, in this buy-and-consume era, few people take the time to do it (international research indicates that as much as 90% of wine is consumed within four hours of purchase), tight, young wines in particular, benefit from decanting. When they are exposed to air, their more volatile elements react, and release scent and flavour. In rare cases too, substantial whites may contain an excess of free sulphur dioxide that gives off a slight odor, which can also be released by decanting,” he says.

Pro-decanter lobbyists propose that moderately mature wine (six to eight years old) can benefit from 15 minutes to an hour in the decanter. Tighter young reds (one to five years old), they say, require between one and three hours to unleash their flavours and smooth out their texture.

Not everyone however, believes that decanting is beneficial. In her book, Oxford Companion To Wine, Jancis Robinson writes: “Authorities as scientifically respectable as Professor Émile Peynaud (a well-known Bordeaux oenologist) argue that this is oenologically indefensible: that the action of oxygen dissolved in a sound wine is usually detrimental and that the longer it is prolonged – i.e. the longer before serving a wine is decanted – the more diffused its aroma and the less marked its sensory attributes”.

This is supported, says wine writer and competition judge, Michael Fridjhon, by the frequently inconclusive findings of decanted versus non-decanted wine trials: “There are, it seems, consistently about as many tasters who prefer their wines decanted as there are those who would rather drink wine poured directly from the bottle.”

Even so, he believes that certain full-bodied young and middle-aged (8 to 20 years) wine can benefit from some aeration. There are certain types of wine that are so intense and tannic that the release of some of their preliminary sensory impressions is an advantage.

While the jury is still out on the exact benefits of decanting younger and middle-aged wines, most agree that older wines (upwards of 20 years) should not be decanted because, as Badenhorst cautions, “they are very delicate”.

Air, it is asserted, can be one of wine’s greatest enemies and, when decanting adds a great deal of oxygen to a good, old wine that has been properly stored, the balance can be upset and the air can cause the fragile fruit to fade away sooner rather than later. What is more, say the experts, one of the most pleasurable experiences, when enjoying an older vintage wine, is to observe and savour the evolution of the wine in the glass. By decanting an older wine, you run the risk that its final fine moment will be squandered in the decanter, rather in your glass.

It is safer to stand older vintage bottles up for a few days before opening them. This way, sediment settles at the bottom of the bottle. Then, suggest those-in-the-know, you can either decant just before drinking it, or drink it from the bottle. Many recommend that you use an appropriately large glass in which to aerate the wine while you drink it. That way, you can enjoy the wine’s evolution at each sip.

There are, of course, aesthetic reasons for decanting wine. Wine in a beautiful decanter – and there are many fine-looking modern, classic and antique options available – can add to the ambience of an elegantly set table and meticulously prepared dinner.

The vessels, which are loosely based on Roman serving bottles, are usually handleless glass containers with stoppers. Although their form has not changed much in recent centuries, shape and decoration have followed fashion.

“Internationally, there has been a move away from elaborately cut crystal glass in all wine accessories, including decanters,” says Alison Joy of Wine Essentials, local supplier of wine accessories. “The current trend is to go for simple, clear glass and the most popular designs in this country at the moment are Riedel’s Ultra and Duck decanters. It is my belief that, these days, most decanters are bought because they are beautiful – they make superb gifts – and add a certain status to the dinner table. It seems that most people accept nowadays that wine is good to drink from the bottle. Decanting is done for aesthetic reasons.”

Riedel, schmiedel, insinuates Badenhorst. He advocates that, besides improving certain wines, decanting has the added benefit of encouraging drinkers to independently interpret wine, without being influenced by what they read on the label.

“Quite honestly, I do not give a damn what I use as a decanter. The point is that decanting can bring out the best in certain wines and makes drinking it more fun,” he says. “When you decant the wine in the kitchen and present it on the dinner table in a decanter – cut crystal or otherwise – your guests are obliged to rely on their nose and mouth to appreciate what they are drinking. That is how wine should be enjoyed.”

(This article first appeared in the Food & Travel section of The Weekender in August 2007.)