From the archive: When should you decant wine? An expert taste test

Decanter's experts investigate the merits of decanting top Bordeaux, Napa Cabernet and Rhône Syrah and how the aeration time can impact taste.

This article compiles articles published across three issues of Decanter magazine between November 2013 and January 2014. It has now been published online and in full for Premium members.

In this article we compare how decanting affects several types of wine:

Bordeaux & Napa Valley Cabernet Sauvignon

Vintage Port

Northern Rhône Syrah & Barossa Shiraz

Scroll to the bottom to see the panels’ conclusions

What goes on in a decanter?

The process of aeration – in effect, a very gentle oxidation – is not that well understood, according to Geoff Taylor of wine laboratory Corkwise.

He portrays a battle of oxygen versus antioxidants being waged at the point at which wine meets air.If that point is very small – as it is in a bottle that has been uncorked but not decanted – the battle will be very slow. If the surface of the wine exposed to air is greater – if the wine has been decanted, double-decanted, decanted and given a shake, or given any other speeding-up treatment – it will be faster.First of all, Taylor says, wine contains natural antioxidants. The younger, bigger and heavier the red wine, the more it will have.

Then there is sulphur dioxide (SO2) usually added at bottling to prevent oxidation before we’re ready for it. SO2 also inhibits the aromas of wine. When the wine is opened, Taylor asks us to imagine a molecule of oxygen coming towards the wine like a football. The SO2, or some other natural antioxidant, grabs the oxygen and prevents it from oxidising the wine.

Gradually, as the onslaught of oxygen continues, the antioxidants in the wine are used up. Oxidation then begins. The oxygen penetrates gradually: the top layers first, then further down. Again, the size of the surface exposed to the air makes a huge difference.

How long will a bottle of wine, opened but not decanted, take to be saturated with oxygen?

A few hours, Taylor says. ‘Liquid forms a strong natural barrier to gas pushing its way in.’ What the oxygen gradually does is return the wine to its near-virgin state, before SO2 was added – but, of course, with all the changes wrought by age being revealed.

If the wine is very old, and especially if it has been stored well, ‘it is a very reductive environment’, Taylor says. Not reductive in the sense of eggy and sulphidey, as we might understand it as a wine fault, but a sort of suspended animation where all processes happen very slowly.

‘All wine will eventually oxidise, but stored well in bottle it almost goes into a hibernation state,’ he adds. ‘Once the cork is out, however, the oxidation process restarts.’ And catches up: imagine removing the Botox rather quickly from a frozen face.

Which wines should be decanted?

The conventional wisdom is correct: a deposit in the bottle signals a need for decanting, or you’ll be straining it through your teeth. That means red wines with tannin and bottle age: Bordeaux, Port, Rhône, that sort of thing.

Professor Emile Peynaud, the late, great transformer of many-a Bordeaux châteaux, believed that separating wine and sediment was the only reason to decant, but Steven Spurrier suggests Peynaud was mostly concerned with preserving freshness, because he spent his life persuading producers to make vibrant wines.

But such prosaic reasons are not the only ones. Wines open with aeration: wine that is tight and glum at first taste can become vivacious and talkative after time in a decanter: it’s the equivalent of charm school. Or it can be.

To what extent can decanting substitute for a few more years of bottle age? That’s one of the things we wanted to find out.

All sorts of wines were decanted in the past: Sauternes, dry whites, even Champagne. Getting rid of bottle stink was one reason: back in ye olden days, wine occasionally smelled quite off when first opened, and aeration let that come away to reveal the beauty beneath. It doesn’t seem to happen now, but with very old wines it presumably could.

In Bordeaux, the usual way is either to double-decant, pouring the wine back into the original bottle and restoppering, or to decant and stopper the decanter about an hour or two before serving.

Burgundy, being less tannic, is less likely to throw a lot of deposit – though old wines might have done.

The more tannic Italian wines were traditionally not decanted, but might be opened the day before. Old Riojas, having been aged for aeons in wood, didn’t throw a deposit in the bottle, so decanting was only necessary if the wine seemed a bit stinky.

In a restaurant nowadays, if you order a red and ask for it to be decanted, and have a white first, the decanter will likely arrive at your table about 45 minutes after the wine has been opened.

So many traditions, so many reasons.

Spurrier: How to decant – A practical guide

Decanting Bordeaux & Napa Valley

Gérard Basset MW MS OBE, Stephen Brook & Steven Spurrier

One of the perennial decanting puzzles is how to adjust the time of aeration to the age of the wine. The usual advice is to give less aeration to old wines. But do young wines benefit from more time?

We picked three vintages for this tasting. We wanted one vintage at its peak, one beginning to drink well, and one young and needing more time.

Jean-Charles Cazes of Château Lynch-Bages suggested 1996 for the mature vintage, 2000 for the nearly-drinking vintage and 2006 for the young vintage. All are very good years – and we approached Lynch-Bages in the first place because it combines both modernity and classicism.

Doug Shafer matched them vintage for vintage with his Hillside Select. Inevitably, the Shafer was not at exactly the same stage of development as the Lynch-Bages – Hillside Select 2006 is more approachable now than Lynch-Bages 2006, for instance – but it was clear why you would lay down Hillside Select for 17 years.

Hillside Select is a Napa Cabernet to its toes, with all the lush power you would expect, but the elegance and structure of a hillside wine. The parallels were good.

Château Lynch-Bages, Pauillac 2006

This was, by any standards, a young wine that none of the panel would have opened for drinking at this stage; but if they had, they’d have expected to decant it. And it became clear that aeration was not a panacea, nor a substitute, for maturity.

Even the wines that had been in a decanter or opened for four hours had not turned into the silky, seductive creature that is a mature Lynch-Bages: the tannins were still pretty brutal, though four hours did a fair job of smoothing them out.

Nevertheless, the four-hour wines weren’t anyone’s favourite. The tannins were smoother but the wines were getting just a touch flat. The just-opened wines weren’t a lot of fun, and the middle ground seemed the happiest place to be: for Gérard Basset, the two-hour wines were best, followed by the one-hours; Steven Spurrier and Stephen Brook agreed.

Which left the question of whether to decant.

‘There weren’t huge differences between them,’ said Brook. ‘In general, the decanted wines were a little more open and sweeter on the nose, and softer on the attack, but on the mid-palate there were no significant differences; the character of the wine stayed the same,’ he said.

‘In the context of a dinner table, with food and the swirl of conversation, would anyone notice?’

Shafer, Hillside Select Cabernet Sauvignon, Napa 2006

Gérard Basset described this wine as ‘readier to drink than the Lynch-Bages 2006; rounder and more approachable. I wouldn’t drink the Lynch-Bages yet, but you could drink this. The texture – everything is different.’ Stephen Brook agreed: ‘It’s more in-your-face. It’s all massive primary fruit, with not much subtlety.’

Decanting times made far more difference here than with the Lynch-Bages 2006. There, tasters found that the wine remained itself no matter what you did to it. Here, since the wine was more evolved to start with, decanting evolved it even more.

For the first time, four hours in a decanter didn’t seem too much, at least to Steven Spurrier. The one-hour wines were very different to the just-opened wines, and the two-hour wines were different again. ‘Both two-hour wines had opened up, but had lost their vibrancy of fruit, so were a bit flat; they hadn’t had time to become complex,’ he said.

‘But I really liked the four-hour wines. That extra two hours allowed the wine to take on new life. Two hours shut it down, and four hours brought it back. It aged a year or two; it was terrific.’ Of the four-hour wines, his slight preference was for the decanted one.

Brook and Basset both liked the two-hour wines best – ‘more complexity’, said Basset, especially the non-decanted wine, and Brook concurred, though found it hard to choose between the two: ‘The decanted wine was more evolved. And both the four-hour wines were lacking in aromatic intensity.’

Château Lynch-Bages, Pauillac 2000

This is a wine that, as Stephen Brook said, you could drink, but it still had a lot of tannins. ‘Initially softer, with strong savoury tones; a touch more rustic than the 2006, but still jolly good,’ was his description. It’s a very rich wine – certainly the richest of the Lynch-Bages trio.

If the panel had seemed a bit baffled after the first flight, they were a lot more confident now. ‘The differences were much more clear cut,’ said Brook. ‘The just-opened and one-hour wines were better decanted; they had an extra dimension that the non-decanted wines lacked: more breadth of fruit, more generosity. At two and four hours, though, it was less clear, and the decanted wines, especially at four hours, had more meaty tones of oxidation, of accelerated development.’ For him, two hours and not decanted was best.

When it came to the two-hour wines, however, Gérard Basset and Steven Spurrier both preferred the decanted versions, and Spurrier preferred the decanted four-hour wine, while Basset found both four-hour wines pretty equal.

Generally, though, four hours again seemed too long. ‘Both were going away,’ said Spurrier; ‘they were losing their freshness.’ This was to become a refrain of the tasting: it was already becoming clear that longer aeration is not better.

Shafer, Hillside Select Cabernet Sauvignon, Napa 2000 

This wine was a lot less evolved than the Lynch-Bages 2000: still all primary fruit with no secondary, savoury tones. Very youthful.

‘For the first time,’ said Steven Spurrier, ‘I preferred the non-decanted wine of the just-opened pair: it had lovely cassis fruit, vigour and freshness. Decanting just allowed it to mature a bit, so that the richness came out. But for the rest of the flight I preferred the decanted version. Two hours helped the decanted wine to open, and show its alcohol, richness and complexity, but the non-decanted wine had stopped in its tracks.’

At four hours he found that ‘the more the wine is open, the more it absorbs the sugars and lets the finesse shine’. Stephen Brook disagreed. At four hours he found oxidation and evolution marked in both wines. ‘They still had massive fruit, but they were flat.’ He preferred the non-decanted wines at all stages (‘more precision, tautness’) except for the just-opened pair, where the decanted wine ‘jumped out of the glass’.

What he especially noticed was that between two and four hours the profile changed: ‘Less cassis vibrancy and more brooding characters – odd as a consequence of aeration.’ His tip was to pour from the bottle, and allow much aeration.

Gérard Basset preferred the decanted wines except at one hour, where he favoured the non-decanted. ‘My least favourite pair was the four-hour wines. They didn’t have that finesse.’ So our trio agreed on the difference created by long aeration, just not on whether they liked it.

Château Lynch-Bages, Pauillac 1996 

Steven Spurrier defined this vintage as ‘a classic Cabernet year with structured wines that are taking their time to come round’. Stephen Brook noted ‘a herbal quality, which I like but which may not be appreciated in the US’.

Brook liked the way the non-decanted wines kept their freshness and vibrancy, except for the just-opened pair, where the brief aeration of the decanted version seemed better. But he agreed that many people would prefer the roundness of the decanted wines all the way through.

It’s a wine that needs aeration, said Spurrier: ‘The one-hour decanted wine shows at its peak, whereas the one-hour opened is still a bit grippy but will keep on developing through a dinner.

Of the two-hour wines, I loved the fresh aroma of the opened wine but it was green on the palate and lacked the chocolate note of the decanted wine.’

The just-opened pair Gérard Basset found similar; of the one-hour wines he preferred the decanted one – ‘more complete, but only by a whisker’ – and the two-hour wines, also, he found to be equal.

The only consensus was that, again, four hours was a bit too long. Basset found the non-decanted version more together; Spurrier found it fresher, ‘though this is not how it should be’; while Brook found it fresher, ‘though some may prefer the decanted wine’s more mellow quality’.

Shafer, Hillside Select Cabernet Sauvignon, Napa 1996 

Stephen Brook described this wine as ‘classic’ Californian Cabernet from a fine year. ‘It has excellent balance, great power and enormous fruit even after 16 years. It’s more evolved than the 2000, but not in a negative way.’

Gérard Basset felt that decanting made more difference here than in the other Shafer flights, as did time; and, accordingly, at four hours he preferred the non-decanted wine. But four hours was, he felt, too long. One or two hours, and decanted, were his favourites – and at these times, particularly at one hour, he found the biggest difference between decanting and not decanting.

Steven Spurrier’s preference was for very brief decanting, an hour at the most: ‘Maybe 15 minutes in the decanter, 10 minutes in the glass is best.’ Longer times ‘act against the fruit and flatten it, so you only get the tannins’.

Brook confessed to being ‘all over the place’ in his opinions. ‘The 1996 holds up to aeration better than the 2000. I liked the four-hour pair here, but I didn’t with the 2000. Each pair had its differences, but it was difficult to know which I preferred.’ His favourite in the flight was the wine decanted at two hours; but of the four-hour wines, he liked the ‘exuberance and vinosity’ of the non-decanted version.

Again, opinions were far more varied and far less clear than they were for the Lynch-Bages 1996. The safest route seems to be to decant the wine, but not for too long: more than two hours is risky.

Decanting Vintage Port

Gérard Basset MW MS OBE, Mel Jones MW & Richard Mayson

Vintage Port is a wine for which decanting is a necessity rather than an option, because of the deposit it throws during its long ageing in bottle.

Getting the wine off its deposit is not, however, the only reason for decanting. Wine that has been in bottle for a long time enters a sort of sleeping-beauty dormancy and needs to be woken up with a blast of air so that it can sing; wine that is still quite young needs aeration to soften its austere tannins and bring forth the fruit hiding in the structure.

Plus, of course, a decanter or three on a dining table look wonderful – more glamorous than even the smartest bottle.

Not all Port needs decanting, but the sort of dinner that invites a bottle of Port to round it off is usually the sort of dinner where a decanter seems appropriate: so even aged tawny is routinely decanted, although it has no sediment and shouldn’t need aerating. Some LBVs – those which are bottled unfiltered – will have thrown a sediment; most won’t. Crusted Port (the clue is in the name) throws a sediment. These are the only Ports for which decanting is a necessity.

Ask for guidance on how far ahead a bottle of vintage Port should be opened and you will get little more than a shrug. Quinta do Noval’s MD, Christian Seely, says ‘I usually decide about five minutes before dinner that I’m going to serve Noval Nacional; otherwise I decant at about 6pm.’

That would give the wine roughly four hours’ aeration before being served. In a restaurant, unless you order ahead, it will get considerably less, though probably more than the 45 minutes or so in a decanter that the red for your main course is likely to get.

As always when deciding how far ahead to open bottles, you should take into account the amount of time the decanter will continue to circulate. We were tasting briskly and moving on; that’s not dinner-table behaviour. It’s much better to allow the wine to open a little in the glass than risk it dying in the decanter – which very old wines can do.

Whereas many in Bordeaux double-decant, serving the wine in the original bottle minus the deposit, vintage Port in the Douro is usually served in a decanter, stoppered or unstoppered.

Stoppering is a useful half-measure if you want to decant well ahead but want to limit the amount of oxygen available to the wine, although we kept things simpler than that to establish some basic guidelines.

Quinta Vale Dona Maria, owned by Cristiano van Zeller, is one of the Douro’s best independent producers, and he supplied us with our young wine, his 2011.

Our youngish wine was Taylors 1997, a classic vintage from a classic shipper – The Fladgate Partnership, one of the two big groups of Port shippers.

Our mature vintage was Graham’s 1980, part of the other big group – the Symington Group.

The choice of vintages is important: the high quality of modern vintage Port (better viticulture has meant silkier tannins and beautiful purity of fruit) means that a trend has emerged for drinking it straight away, before it enters its closed period at three or four years old.

Quinta Vale Dona Maria 2011

This is a glorious Port vintage, and this quinta, taken over by Cristiano van Zeller in 1996, has great vineyards in the Rio Torto valley with some very old vines.

When we tasted it, the wine had been in bottle about three months; it was young, obviously, plump, and with marked sweetness and alcohol. Basset found it ‘not particularly expressive on the nose’ and Jones commented that while you could drink it now ‘it hasn’t done anything exciting yet’.

If you were going to drink it at this age you would not need to decant it, since after just three months there wasn’t even a hint of deposit; and logic would suggest that a wine this young would have least to gain from aeration.

Certainly four hours’ aeration didn’t seem to suit it, causing the fruit to fade. For Mayson, the decanted wines were a shade better, especially at one and two hours, and Basset agreed; so, basically, did Jones, though she found the one-hour decanted wine bizarrely more tannic than its non-decanted equivalent.

The differences overall were small, however, and they showed on the nose much more than on the palate, with the aromas reviving then, after four hours, showing signs of fading.

Taylor’s 1997

The tasters had to navigate considerable bottle variation here. ‘It’s balanced, still firm, with ripe tannins and showing well,’ said Mayson. ‘It’s on the cusp of being ready to drink.’

Here again, it was the aromas that changed most with decanting. ‘Almost all the palates were identical in each pair, decanted and non-decanted,’ said Jones. Given that the wine is almost ready to drink, one would expect aeration to be the touch on the tiller needed to make the aromas jump out of the glass.

Mayson’s favourite was the one-hour, non-decanted wine; Jones’s the just-opened and decanted wine. Basset’s preference was for just-opened and decanted, and one-hour opened; the differences were small, but less aeration was considered better than more.

‘I like freshness, and to see the wine develop in the glass,’ said Mayson. ‘Of the one-hour wines, most people would prefer the decanted; it’s more approachable. But I prefer the non-decanted.’ The others agreed: ‘the palate seems more integrated,’ said Jones.

Bottle variation made it difficult to judge the two-hour wines – the decanted wine had TCA notes – and the four-hour wines, though holding up pretty well, were nobody’s favourites. Indeed, it’s possible that bottle variation distorted the results, making the wines with less aeration more appealing.

Graham’s 1980

Jones summarised the wine as ‘absolutely ready, beautifully evolved and complex’. Mayson added, ‘It was a Cinderella vintage which surprised everybody, and the Symingtons produced some cracking wines.’

As this, like the Taylor’s, is a wine that would undoubtedly have to be decanted, it was just as well that the tasters marginally preferred the decanted wines all the way through. But only marginally: again, the differences were more on the nose than on the palate. Time made more of a difference, with the four-hour wines winning more approval than in either of the other flights.

However, even though the scores were in fact remarkably consistent across the flight, there was less agreement on favourites than in the other flights.

The impression is of a wine that you can treat pretty much how you like, and it will come up smiling. Is this a reflection of age and perfect maturity? It was very fresh; almost more youthful (given its age) than the Taylor’s. Said Basset, ‘There are 17 years between this and the last wine, but not 17 years difference in flavour.’ It certainly provided an enjoyable end to the tasting.

As Mayson said, ‘We were looking for small differences in this tasting, but for readers, after dinner, at 11pm, it’s not so crucial.’

Decanting Rhône Syrah & Barossa Valley Shiraz

Gérard Basset MW MS OBE, Stephen Brook & Matt Wilkin MS

Neither M Chapoutier’s Monier de la Sizeranne or Henschke’s Keyneton Estate Euphonium is the most expensive wine of its region; they’re the sort of wines that Decanter readers might have at home.

The first is pure Syrah from several different sites; the second is a blend of about 70% Shiraz with varying percentages of Cabernet Sauvignon and Merlot, grown in the Barossa.

Hermitage is one of the more aromatic, less chunky wines of the northern Rhône, and Henschke is famous for its balance of delicacy and concentration. We had three vintages of each: a young vintage, a vintage just coming up to drinkability, and a mature vintage. We left the choice of vintages, within those parameters, to the producers.

Chapoutier sent the 2010, 2007 and 2001; Henschke matched with the 2010, 2006 and 2002.

M Chapoutier, Monier de la Sizeranne, Hermitage 2010

Brook described this wine as ‘lacking flesh and succulence at first, but in the glass it gained more fruit weight. It’s still young and reserved but the integration is very good. It needs time’.

But even at this age you could still enjoy it. ‘It has a fingerprint of where it comes from,’ said Wilkin. It was also remarkably consistent and resilient across the flight – even four hours in a decanter couldn’t entirely flatten it. But four hours is not recommended.

Of that pair, the non-decanted wine was preferred but was still nobody’s favourite. The decanted four-hour wine was ‘stubborn’ said Wilkin. ‘It was like it had opened and gone back to sleep.’

Brook’s preference was for the one-hour wines and, of those, he most liked the decanted wine; he also liked both two-hour wines – as did Wilkin, but for different reasons. ‘On the decanted two-hour wine the acidity felt more refined, but on the non-decanted one I liked the acidity on the finish. It’s 50:50’

The just-opened wines had their charms too. Wilkin found the decanted wine ‘more open, settled and expressive, whereas the non-decanted wine was less floral, with a heavier nose’; Brook preferred the non-decanted wine. The main difference, said Basset, ‘was on the palate, not the nose, with the opened wine often being tighter’.

Henschke, Keyneton Estate Euphonium, Barossa 2010

‘A gorgeous wine,’ enthused Brook, ‘with eucalyptus freshness and great vibrancy. You could drink it now, because the tannins are so supple and it’s so well balanced, or you could keep it for another eight to 10 years.’ He said it seemed to have no adolescent awkwardness at all; far less puppy fat: ‘It’s like a racehorse!’

This wine was so consistent across the flight that the tasters had to resort to hair-splitting. ‘The decanted wines, as with the previous flight of Rhônes, had slightly more aroma and were slightly more open, but on the palate I struggled to find any significant differences,’ said Brook. ‘My scores were within a quarter of a point (/20) all the way through.’

He gave the edge to the two-hour decanted wine, but it was only an edge. Basset agreed: ‘The first pair (just opened) had a slightly hard edge, but after that they were equal. Two hours was the best, but not by much.’

Wilkin agreed that changes over time, such as they were, were more marked on the nose. The two-hour decanted wine was his favourite of the flight: ‘It showed more harmony on the palate. The two-hour, non-decanted wine was more stubborn.’

And at four hours the wine was still going strong although, as Brook pointed out, ‘there’s no real advantage to opening it four hours ahead’.

M Chapoutier, Monier de la Sizeranne, Hermitage 2007

An ‘ethereal’ wine, said Basset: ‘Mid-weight, showing some evolution, with lifted aromas of plum, jasmine and cherry.’ But to drink now or keep? Basset thought this 2007 could really be enjoyed now, or soonish – ‘It doesn’t have the power to keep for another 10 or 15 years.’

It also threw a spanner in the works as far as reaching tidy conclusions was concerned. Having mostly preferred the decanted wines in the first flight, everybody mostly liked the non-decanted versions of this vintage.

Wilkin ‘preferred the non-decanted on every count except for the four-hour pair’. Brook found that the two-hour wines were pretty close and ‘the fruit had darkened a bit on the nose. The one-hour wines showed more red fruit’. Of the two-hour wines he preferred the decanted, but that was the exception for him; and again, the four-hour wines got a general thumbs-down. ‘They were softer, and lacked energy,’ said Brook.

Why didn’t decanting flatter this wine? A general shrug followed this question. ‘If the producer was in the room,’ said Wilkin, ‘he might say, don’t decant the 2007, just open it.’

Brook added: ‘Decanting this vintage helps the aromas a bit, but there’s very little to gain from it.’ Basset added: ‘Maybe the ’07 has enough aroma, so it just doesn’t need decanting?’

Henschke, Keyneton Estate Euphonium, Barossa 2006

Basset felt this wine ‘hasn’t completely developed but it has some tertiary aromas; less fruit than the 2010 but lovely sweet spice’.

‘It’s comparable to the Hermitage 2007 in terms of development,’ added Wilkin, ‘though the Hermitage had more tertiary characters.’

As with the 2010, differences between the wines varied from small to non-existent. Wilkin found more evolution on the one-hour decanted compared to its twin, and more notable differences between the two-hour wines, with the non-decanted one being ‘more restrained on nose and palate, with the oak more dominant’.

At both two and four hours he preferred the decanted wines for their ‘meaty notes and more settled fruit’. Brook agreed there was a ‘savoury, meaty’ character at two hours, and more so at four hours. ‘I don’t mind that, but some may prefer the freshness of the one-hour wines.’

At one hour he also preferred the decanted wine: ‘It was more complex. The non-decanted wine had firmer tannins and a blunter finish.’ The non-decanted two-hour wine didn’t find much favour with anyone: ‘A bit tired,’ said Brook, ‘and without the length of the others.’

Overall, aeration gave a savoury character that may or may not be to some tastes, but such nuances would hardly show over dinner. Though four hours was a nuance too far for the wine.

M Chapoutier, Monier de la Sizeranne, Hermitage 2001

This would still keep for another three to five years but ‘it’s at its best now’ said Basset. Wilkin described it as having ‘lovely density, upfront ripeness and development of plum and prune. At this age you get expression of hay and molasses, which persists, plus garrigue notes and a rare meat element.’

Wilkin marginally preferred the opened wines, Brook and Basset the decanted ones, but the differences were not enormous – for Brook, a half a point maximum. ‘Where aeration helped was in rounding out the tannins and opening the aromas,’ he said.

‘Decanting improved the nose,’ said Basset, ‘but I’d have liked a bit more flesh on the palate, if I were to drink it without food. With food it would be wonderful.’

Wilkin agreed that decanting gave more tertiary development on the nose, but the decanted wines were more brittle. ‘On the non-decanted wines the fruit was softer and juicier, and the tannins were riper. I prefer the juiciness of the non-decanted bottles, and the expression on the nose of the decanted.’

But the surprise was how well this wine stood up to four hours: ‘Better than the younger wines,’ said Brook. ‘There was no flagging, and it still had tension and imposing tannins.’

Henschke, Keyneton Estate Euphonium, Barossa 2002

‘By waiting for this sort of maturity,’ said Brook, ‘you get more roundness. The wine is fleshy, but you lose a bit of vibrancy.’ With aeration ‘the structure is so tight, the acidity is so fine, that it’s difficult to do much wrong’. ‘Pretty bulletproof’ was Wilkin’s description.

For Basset, this was the first Henschke flight where he found marked differences, but still less than with the Hermitage. Wilkin said ‘The decanted wines were always more settled, but you lost some fruit on the palate. The non-decanted bottles had more core fruit and less cedary, tertiary aromas.’

Within that generally agreed formula, preferences were a question of personal taste. Brook liked it decanted at just-opened and one hour (‘you got more aromatic evolution without losing the sleek texture and fruit purity’) and not decanted thereafter, though he noted it ‘survived four hours effortlessly’.

Wilkin agreed, but was torn on the two-hour wines (‘same mark, different reasons’) and by four hours ‘they were losing a little fruit’. For Basset, one hour was the perfect time, and he had a slight preference for the decanted wine.

Would you decant this wine if it had no sediment? Brook’s preference was ‘pull the cork and drink’; Basset and Wilkin thought that if you decant late it will do no harm.

Methodology

There are two things to consider: how long to leave a wine in the decanter; and how decanting compares with simply opening the bottle. So we settled on four aeration times:

• four hours
• two hours
• one hour
• immediately before serving.

Two bottles of each wine were opened at each of these times; one was decanted, one not. The stoppers were not put back in.

The decanters, supplied by Riedel, were of a classic shape that exposes a large, but not exaggerated, surface to the air. The wines were kept all day in our air-conditioned tasting room, so were served at the same temperature as at all our tastings.

All were decanted by Gérard Basset (see video on Decanter.com) and were served in flights to a precise timetable, so the aeration times stayed accurate throughout.

The wines were not tasted blind. We departed from our usual practice here because we weren’t trying to determine which wines were best.

Wines opened just before the tasting, rather than an hour or more ahead, are referred to as ‘just-opened’, whether decanted or not. The wines that were opened but not decanted are referred to as ‘non-decanted’.

Conclusions

• Some aeration is usually better than none
• Decanting too early is worse than too late

Decanting one hour ahead is consistently good. Opening for two hours is not the same as decanting for one hour. Decanting two hours ahead can work well for younger wines. Longer decanting periods are risky, and the more evolved the wine, the greater the risk of oxidation in the decanter.

• Long aeration is not a substitute for bottle age: a long-decanted young wine will still be young, but tired
• Decanting then putting the stopper in the decanter can be a useful halfway house
• Very rich wines keep their freshness more by being opened and not decanted
• Very tight wines can open up with decanting
• Syrah and Shiraz show far greater consistency over different aeration times than Cabernet Sauvignon, and can stand up to long aeration much better:

The differences between decanted and non-decanted wines are small, especially compared with Cabernet Sauvignon. Decanting opens the nose, but you may lose fruit on the palate. For Rhône Syrahs, it may be better not to decant lighter, less muscular years. Aussie Shiraz (or at least this one) seems to be bomb-proof: decant or not, as you please

• Decanting is necessary for all but very young vintage Port, because of its sediment:

Very young vintage Port, drunk ‘on the fruit’, is better with less aeration. Decanting vintage Port makes it more aromatic; aroma is affected more than taste.

• Remember that the wine will continue to evolve as it circulates on the table

Compiled and edited for Decanter Premium by James Button.

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