By | November 12 2015
Premature oxidation, premox, or indeed just plain pox-these terms cover the imperfectly understood incidence in recent years of unduly advanced, sometimes completely oxidized bottles of wine-especially white Burgundy.
The issue is frustrating not just because of the significant numbers of underperforming or, indeed, undrinkable bottles but also because we don’t know the causes for certain, nor the extent of it-the size of the problem within Burgundy, the extent to which it affects other wine styles and regions, or for how much longer we are likely to be afflicted.
There are too many factors at play. Some are measurable and correctable; others, a matter for conjecture. Even those seemingly based in wine science are capable of different and opposing interpretation. The following is a summary of what I have understood from a mixture of my own experience, talking to producers, and reading other views on the subject.
I would like to thank Nigel Groundwater and Toby Morrhall, among others, for their helpful input.
Steve Tanzer, in his International Wine Cellar, was perhaps the first wine journalist to raise the issue publicly, in 2002. Since then, Allen Meadows has provided useful reports on the pox in his Burghound newsletters, and while I don’t agree with all his thoughts, these articles do supply a useful retrospective timeline on how the story broke. He also first mentions it in 2002 (issue 8); and even in issue 16 (October 2004) the tone of his article is that the problem relates to a few bottles rather than to particular producers or, indeed, the industry as a whole. But by issue 20 (October 2005), his view has changed and he is taking it seriously as a major scourge. Annual reports thereafter continue to bemoan the problem while providing insights into the latest theories.
The first vintage that really showed a problem was 1996, though subsequently it became clear that 1995 was also implicated. Another major source of information, oxidized-burgs. wikispaces.com, has the timing the other way around. The end of the story is not yet clear either: I am not ready to offer a clean bill of health, though many individual producers who were affected have taken significant steps to resolve the problem at their specific domaines. The risks attached to particular vintages are discussed at the end of this article in the section titled Vintage Variation.
The question of how and why premature oxidation emerged so rapidly remains unanswered. If we could more clearly identify the causes, perhaps the timing would be explained as well. Possible part explanations will emerge during the course of the discussion.
How does wine oxidize?
What is happening when wines oxidizes? Or alternatively, what is it in wine that is oxidizing? Partly it is the phenols, and partly it is the alcohol (ethanol).
The phenols come in two types: the flavonoid phenols that are to be found in the skins, pips, and stems; and the non-flavonoid phenols in the pulp of the grape. The former will typically be more easily extracted by a hydraulic press, while even a soft pneumatic press will extract the latter. Oxidation of the first group causes the wine to change color (through deeper yellows to brown), though arguably if this happens up front, before fermentation, it is not going to cause a problem later on. The non-flavonoid phenols do not produce any detectable changes if they oxidize. Pierre Vincent of Domaine de la Vougeraie protects the first juice that runs out of his pneumatic press but allows the end of the press run, when the flavonoid phenols begin to be extracted, to oxidize overnight. This is to oxidize the flavonoid phenolics that otherwise impart bitterness to the wine and, anyway, tend to oxidize immediately if they can. The following day, he cleans up this part of the juice with some sulfur and reintegrates it with the free-run juice. Dominique Lafon and others follow a very similar practice.
Then there is the ethanol, present in the fermented wine but not yet in the juice coming out of the press. Ethanol (also known as ethyl alcohol) is written as CH3 CH2 OH or alternatively as C2 H6 O. With the presence of oxygen (O), it will oxidize into acetaldehyde and water, CH3 CHO plus H2 O. This is definitely bad news and, I understand, not reversible, though free sulfur can mitigate the negative attributes of acetaldehyde to some extent. Bordeaux researchers have identified various compounds that emerge as a result of oxidation, each with a distinctive flavor. The latest is sotolon, which can be formed in the presence of acetaldehyde. Its distinguishing aromatic character can include curry and rancid walnuts, though these may not be associated in any obvious way with oxidizing wine!
Is only white Burgundy at risk?
Clearly white Burgundy is the category where there is the greatest volume of wine that has been laid down in cellars with the intention of benefiting from the additional enjoyment that a mature bottle of fine wine should offer. As such, the brunt of premature oxidation has fallen on white Burgundy.
I have also experienced the phenomenon, though, with California Chardonnay, white Rhône wines, white Bordeaux including Sauternes, and Loire and Alsace wines, to offer a selection that comes immediately to mind but is not exhaustive. I have occasionally witnessed it with red wines, though rarely, and it is likely that the tannins present in most red wines will offer significant additional protection.
One of these areas, white Rhône, is worth exploring a little further. For years, Rhône aficionados have put forward the theory that the region’s major white wines should be drunk either in youth or considerable age, in between which times the wines appear to lose their freshness and balance. There are parallels here with what we are currently seeing in some cases of premature oxidation of white Burgundy, if my contention in the section above that this may be transient in some cases proves to be valid. Has climate change brought the white Rhône phenomenon northward?
Without having engaged in any statistical survey, I think that the actual incidence may be higher with white Burgundy than with other wines. Dubourdieu and Lavigne from Bordeaux, however, have written: "It would be wrong to think that this problem affects white Burgundy more than any other wines because of some mystical influences found only in that region. In fact, premox affects all white wines, still and sparkling, dry and sweet, and all grape varieties and origins. The issue is identical for white wines everywhere, with the same causes and the same effects."
Is premox really oxidation?
A wine that has oxidized naturally over a long period will be a deep yellow in color, perhaps even browning, and the bouquet will smell of cooked fruit, perhaps quinces, eventually dank, dead fruit, possibly sherried and acetic, once the acetaldehyde comes into play. Typically all these negatives will be immediately apparent on opening and pouring.
A prematurely oxidized wine will also show some advance in the color, more in the dull yellow range, and this may happen after the bottle has been open for a minute or two. The first danger sign on the nose is one of bruised apples or furniture polish (apparently caused by the oxidative degradation of indolacetic acid), which again can strengthen considerably with just a little aeration. The bottle can be passed as okay on first inspection and then deteriorate rapidly within a few minutes. However, I put forward these suggestions about the difference in style between premature and regular oxidation somewhat tentatively.
As a wine professional, I am pretty sure I can tell if something is oxidized: the color, the bouquet, the taste on the palate. But what if I am wrong? What if there is another effect that shows the same symptoms but is in fact a different process? I wouldn’t even entertain the notion if it were not for one factor: On a number of occasions I have experienced wines that appeared to be oxidized that have subsequently returned to the fold.
At one time, almost every wine from 1996 appeared oxidized. I stopped drinking them but didn’t throw any of my remaining bottles away. Now (2013), the incidence of oxidation is very low, and when it does occur it is usually in bottles with a slippery (silicone-treated) and thus inadequate cork. So, something appears to have changed over the intervening period, if my perception is accurate. Jamie Goode’s excellent article ("Beauty and the Beast: Premature Oxidation," WFW 14, pp.86-92) cites Michel Bettane, the leading French critic, as having experienced the apparent reversal of oxidation, or at least the reversal of apparent oxidation, again in relation to the 1996 vintage.
The most astonishing case in my experience came during a tasting of several vintages of Domaine Bonneau du Martray’s Corton-Charlemagne. The 1996 was a dark brown on opening and smelled as though it were almost completely oxidized. I fancied there might still be a vestige of fruit on the otherwise oxidized palate, which was a surprise given the dark brown color. But wait… The color after just a few minutes of aeration was now a much paler brown-and 20 minutes later this was the best wine of the evening. A neighbor has experienced something very similar with some 2000 Chevalier-Montrachet from Colin Deléger.
I can only infer one of two explanations: Either oxidation is reversible, or else the symptoms of oxidation that seem compelling are in fact something else. Those with a better grounding in chemistry than I suggest that the conversion of ethanol to acetaldehyde is not reversible-but perhaps the oxidation of flavonoids can be. Certainly all winemakers have experience of detecting some oxidation in barrel or tank and reversing it with a judicious dose of sulfur.
It should also be noted that (a) some wines that have oxidized in a normal manner have been described as premoxed, and (b) such is the fear of this issue currently that many wines are immediately accused of the pox if there is the faintest hint of oxidation (or sometimes other deviations), when time in the glass might deliver a fine and untainted wine. Tanzer was taken to task for suggesting something like this back in 2008, but he may well have been right.
So, what has changed that has given rise to so many prematurely oxidized bottles, starting with the vintages of the mid-1990s? There are plenty of individual causes that can be cited and, indeed, will be below, but there are two more general issues that need to be considered.
The first is climate change-a subject that itself is hard to pin down scientifically without controversy. What has caused it is not germane to our issue here, but the fact that it exists, whether as a short-term cycle or part of a long-term trend, seems to me undeniable. Two growers of my acquaintance-Pierre Overnoy in the Jura and Jean-Yves Devevey in Burgundy-have the habit of picking a typical bunch of embryo grapes on the same calendar day each year and preserving them in a jar. These jars are then lined up, from which it becomes obvious that over the past 30 years the growing cycle has become more precocious (albeit with occasional exceptions, such as the tardy ’04 following the exceptionally early ’03).
I have heard the theory trailed that the onset of premox might be related to a change in solar activity. It is certainly true that solar flares do follow a cycle, usually of around 11 years, but the timing does not appear to work, 1995-96 falling in a period of low solar activity, and most scientists do not associate solar activity with the onset of climate change. In general, it is clear that grapes are being picked riper than they used to be, due to a mix of climate change, viticultural advances, and winemaking choices, which have an impact on the physiology of the grape at harvest time and the acid balance of the grape juice.
Let us tie into this the zeitgeist of what I might call eco-elegance. Producers want to make the most ecologically sound wines they can, and the most elegant wines. This last, I believe, is especially related to the huge success of red Burgundy over the past 25 years. The world has fallen in love with the finesse of Burgundian Pinot Noir as producers have moved away from a monolithic approach and sought to make wines of elegance, balance, and style. It seems to me that many have started to apply this same profile to white Burgundy, which may well be a cardinal error. If Pinot is a ballerina of a grape, Chardonnay is more of a rugby player.
This trend toward elegance has influenced winemaking in various ways discussed below, augmenting the risk of early oxidation. So, too, has the desire-perhaps requirement, even-to make wines that are approachable earlier than in the past. This is partly to do with a perceived lack of patience on the part of the eventual consumer and partly to do with the enormous growth in tasting judgments. A generation ago, it was only professional importers who used to visit producers in their cellars and make judgments on wines before they were bottled. They were trained to do so. Now many private customers want to taste for themselves, even at the en primeur stage, before making their purchases, and all expect to be able to compare the tasting notes of a host of professional critics, should they so wish. Wines are being made to be attractive from the outset.
In the vineyard
Some have offered high yields as a potential cause, but did yields suddenly become higher in the mid-1990s? Two fine and very long-lived vintages from the 1970s (1973 and 1979) were, at the time, the largest ever crops of white Burgundy. They have been easily eclipsed since, but the area under vine to Chardonnay has also increased significantly.
It is hard to be sure, but some feel that the increasing use of clones, some of them highly productive, may be a factor. Do such high-yielding vines produce grapes with lower phenolics? In the period under review for premox, excessive yields might have a role to play in 1999 (see Vintage Variation at the end of this article for details), but otherwise I am hesitant to cite yields as a likely significant cause.
Anne-Claude Leflaive, in conversation, suggested that the mistreatment of the vineyards in and before the 1970s, with herbicides, pesticides, and chemical fertilizers, could be responsible for the premox problems, but I do not see any timeline logic here. There is no reason for the phenomenon to arrive suddenly in 1995. Leading Bordeaux researchers Denis Dubourdieu and Valérie Lavigne have come up with the opposite theory: that modern ecological techniques, such as abstaining from herbicides and encouraging grass to grow between the rows, has altered the nitrogen balance, which then affects the performance of the antioxidant glutathione.
In laboratory experiments, musts with the same initial amount of glutathione but varying amounts of nitrogen fermented sluggishly at lower levels of nitrogen and left much less glutathione, with its antioxidant properties, in the fermented wine.
The following thoughts on what happens during vinification are contentious. Quite often one hears radically different views, with the same technique being advocated by some as a cause of oxidation and by others as a preventive measure. And once again, it is not clear to me that changes in technique are closely allied to the sudden appearance of the pox in the mid-1990s. There may be some correlation, but it is rarely clear-cut.
The change from hydraulic to pneumatic presses is often cited as a factor, for a variety of different reasons. The first pneumatic presses arrived in Burgundy in the 1970s, but it was not until the mid-1990s that they had really taken over from the hydraulic version. It is certainly true that the first generation of pneumatic presses tended to protect the juice from the air and thus oxygen, so that oxidases remained in the juice unoxidized, whereas in the past those elements that wanted to oxidize easily would have done so at this early stage and would have been discarded either during the settling or fermenting stages. Some producers still protect the emerging juice with SO2; others protect all but the last juice to emerge; still others don’t protect at all, on the basis that anything that oxidizes while the juice is still juice and not wine will fall out of the picture long before bottling.
The other aspect of presses is purely physical. The pneumatic press, into which almost all producers these days tip their whole bunches without crushing the grapes first, keeps the skins more or less intact. The hydraulic press mashes up the skins, something that is anathema to a Pinot Noir producer but may not be so critical with Chardonnay. Indeed, previous generations frequently crushed their grapes before they went into the press. This triturage, the mashing of the skins, will liberate many more phenols into the juice. The resulting wines appear altogether greener, both in the tint of the color and in aromatics. Nowadays we appear not to like this. We may be wrong.
It is evident, however, that in the past couple of vintages more producers are considering crushing before pressing, at least as long as the skins of the grapes are healthy.
The juice now flows, or is pumped, from the press into a tank, where it is left to settle. A very few producers send the juice straight, unsettled, into barrel. The norm is to leave the juice in a tank-perhaps overnight, perhaps longer-so that the solids settle out at the bottom and the juice above falls clear. Those in search of the greatest elegance will use the clear juice and little if any of the hazier liquid below. Yet it seems likely that, in rejecting the solids, the winemaker may be throwing out a major source of antioxidants.
It’s a battle between purity and phenolics. Bernard Hervet of Joseph Faiveley has mentioned that he never finds premox in wines with a green tint to the coloring. Yet even some producers who are fighting hard on the technical front to overcome the risk of premature oxidation simply can’t bear to follow the phenolic path. Phenolics do not correspond either to purity or to a reflection of terroir in this view, and indeed many New World tasters would use "phenolic" as a pejorative descriptor. But perhaps this is a reflection of the need to judge wine young, and such overt phenolics in youth can become interesting, complexing factors in age. As I type this, a vision of 1979 white Burgundy springs to mind, or Coche-Dury Meursault.
Note also, however, the thoughts of Dubourdieu & Co, who emphasize the importance of glutathione levels (see above). They maintain that more phenolics mean less glutathione, and they also believe that the alcoholic fermentation should start rapidly, which implies cleaner, more settled juice. Dubourdieu and Lavigne are very keen on prompt, efficient fermentations to avoid risk of oxidation.
The wine is now in barrel, where it may ingest a certain amount of oxygen through the wood-more so if the barrels are new. And it may be that during the period in question there was a move toward a higher proportion of new wood-a trend happily now in reverse. Many producers are moving toward larger barrel sizes, such as demi-muids, for their white wines, partly to reduce the uptake of new-wood flavors into the wine and partly to reduce the ingress of oxygen in proportion to the volume of the wine.
Meanwhile, the wine in cask will be protected by the lees, autolyzed yeast cells that precipitate to the bottom of the barrel. A leading enologist in Bordeaux rediscovered an ancient Burgundian technique and reintroduced it to the Côte d’Or: bâtonnage, the stirring up of the lees cells. The theory was that the lees would do more good, including in its antioxidant role, if reintegrated into the main body of the wine than it would just lying at the bottom of the barrel. The counter-theory is that this bâtonnage is an aggressive, intrusive procedure that would of itself make the wine more prone to oxidize and could even introduce air if not done under a blanket of inert gas. Some producers now roll the barrels in order to stir the lees without ingress of oxygen.
White wines are more often filtered in Burgundy than red wines are, partly because many fewer are kept for a second winter in barrel. Some think that the filtering process is further removing antioxidants, while others believe that the practice of the purist school in not filtering their wine has left oxidizable material in the wine. I am not convinced that either opinion has much relevance to the oxidation question.
However, the practice of delaying the bottling from just before the next harvest, by leaving the wine en masse for a few months in tank, is probably beneficial in fighting premox, because it allows procedures such as fining and filtration to take place separately from the bottling and for sulfur doses to be added in stages to ensure a stable wine before bottling.
Sulfur is an antioxidant. Sulfur dioxide (SO2) in significant concentration clogs up your nose, catches the back of your throat causing you to cough, and masks the fruit. We don’t like it-but maybe we need to put up with it a little more, as used to be the case.
The "natural wine" movement is little present in central Burgundy, though the neighboring regions of the Beaujolais and the Jura have numerous adherents. This is not the moment for a discourse on either the movement or, indeed, its name. The most evangelical of the natural exponents condemn the addition of sulfur during winemaking or at bottling. Meanwhile, producers of white Burgundy are finding that they need to increase their sulfur levels. We are concerned here with free sulfur-that which has not yet bound with oxygen but is available to do so in the future.
Very roughly, the timeline has gone like this: In the 1980s and before, significant quantities of SO2 were used, detectable to the taste while the wines are young. By the mid-1990s, in the desire to produce fresher, more elegant wines that would show well in youth, sulfur levels were reduced to perhaps 15-20 parts per million (ppm) before bottling; more recently, free sulfur levels have often been increased to 30-40ppm. Various figures are quoted by different people, but it is suggested that the effect of the bottling process can eat up around 15ppm of free sulfur- which in the mid-1990s/early 2000s period would leave almost nothing for the rest of the wine’s life in bottle.
And there are other complicating factors. In order to know what level of SO2 you require, you need to know how much oxygen is around for the sulfur to combat. Detailed trials in Burgundy have shown that different heads on a bottling machine can allow quite different amounts of oxygen into the bottle as it is being filled with wine. (This might therefore be another factor in the conundrum of some bottles in a case being oxidized and others not.) We need to know how much dissolved oxygen is in the wine at the time of bottling in order to know how much SO2 will be required. Now that this part of the issue has been identified, it is fortunately relatively easy to manage, albeit often requiring a change of bottling equipment.
Not only have corks damaged too many bottles of wine through TCA problems, but they have also not been doing their job in sealing the bottles properly in recent times. At one point, I felt that the major players in the cork industry were spending their money on public relations in support of their imperfect closures, rather than on research and development to make them better. I do now feel, however, that the cork industry has significantly improved its overall performance.
A standard response from producers when premox first became apparent in Burgundy was that the corks must be to blame. How else to explain the random nature of the phenomenon? If every bottle was bottled at the same time using the same methodology, then it must be that the cork was the only variable that could explain how some bottles had oxidized while others taken out of the same case at the same time had not. A tempting theory, perhaps, but clearly not the whole answer.
This was the worst period for corks: By the mid-1990s, world wine production in bottled form had increased significantly with the coming of age of various New World countries, none of which had yet moved to wholesale screwcap bottling, which really took off in the Antipodes around 2000-02. It has been suggested that cork-oak trees were now being planted on unsuitable land, at the wrong density, and that existing trees were being harvested too rapidly, with insufficient intervals between crops. The bark was also being cut too close to the ground. Certainly, judging from bottles I have opened, there have been too many corks from this period that are altogether too spongy and provided an insufficient seal to the bottle. Those producers who used multiple, and identifiable, cork suppliers reported a significant variation in performance on the premox front between suppliers.
It has been suggested that corks treated with hydrogen peroxide (instead of chlorine, a move employed by some cork producers to avoid TCA problems) have caused a reaction that has either led to oxidation itself or inhibited the antioxidant effect of the sulfur. Others doubt the relevance of hydrogen peroxide after the washing process that the corks subsequently undergo.
Corks have also been treated with silicone, which, it now appears may eat sulfur. Dominique Lafon took some potentially problematic bottles to be analyzed and found total sulfur levels in oxidized bottles reduced from 100ppm at bottling to 50ppm-which is impossible unless some agent has eaten the sulfur. (Free sulfur can of course reduce as it binds with oxygen, but total sulfur should not be able to.) Silicone-treated corks have also had a tendency to slide out too easily, clearly allowing some oxygen ingress. The alternative paraffin treatment, to which those with bad experiences with silicone migrated, has tended to make the corks stick rather than slide, so they can be hard to remove.
In Burgundy, few producers have been willing to embrace screwcaps, but several high-profile names have switched to Diam, partly in response to a vigorous campaign by the Wine Society’s Burgundy buyer Toby Morrhall. Other options include Vinolok glass closures and the high-tech Ardea Seal closure championed by Laurent Ponsot. These allow ingress of oxygen up to 90-120ppm over ten years while maintaining a perfect seal because the polymer that is used molds against the neck of the bottle. Some smaller-scale producers complete their packaging with wax rather than a foil capsule, as a further level of protection.
Producers of high-quality wines have moved to longer corks-though this has sometimes necessitated changing their bottles, especially half-bottles, to ensure that the cork remains flush with the neck of the bottle for its entire length-and now to thicker corks, with a 25mm (one-inch) diameter, again to enhance the reliability of the seal, the theory being that a wider cork will be compressed more, and therefore be less porous, when forced into the neck of the bottle, which is of a fixed size.
(An additional, anecdotal footnote on corks: Chuck Miller has recently discussed in a thread on wineberserkers.com his experience with the incidence of mold on corks. Though there is no conclusion to be drawn from the absence of mold on a cork, he has not found any incidence of premox in bottles that do have some mold on the external end of the cork. No scientific explanation is offered, just the observation.)
To conclude on the role of the cork, I am persuaded that this has been a significant factor in prematurely oxidized bottles. Where a wine is in a condition to be susceptible to oxidation, a faulty closure will certainly exacerbate the chances of a bad result. The quality of corks now being used by the better Burgundy producers is certainly higher than it was 10 to 15 years earlier; but even so, corks will have variable porosity. It is also happily true that the incidence of TCA-contaminated wines has been drastically reduced.
The phenomenon known as premox has been evident since the early 2000s, as seen initially through the 1995 and 1996 vintages, and has not yet been successfully eradicated.
Two specific reasons, among others, have been identified: inadequate corks and low sulfur levels. These should no longer be the cause of any ongoing problems. Some producers are abandoning natural cork in favor of other closures, such as Diam.
In addition to the specific points noted above, the oxidative potential of white wines appears to be higher now (post-1995) than in the past. Many theories exist regarding the pressing, vinification, and barrel aging of white wines, but viewpoints are often contradictory in relation to the specific processes.
The desire to make wines that are attractive to be drunk, or at least to be tasted, young may not be reconcilable with the previous performance patterns that enabled wines to evolve slowly toward their peak over a decade or two. More work is needed on the role of phenolics and white wine.
Some versions of the phenomenon appear to be temporary. Is it the apparent reversal of oxidation-which may perhaps be possible if the oxidation process has not gone too far-or the reversal of apparent oxidation, if we are sometimes mistaking other complex processes for oxidation? I am far from certain of either of these things, though they might mean that the total incidence of oxidized wines may not be quite as high as we fear.
The core problem is that specific issues relating to cork and sulfur have coincided with a period when the oxidation potential of white wines has been higher than in the past. Steps can be taken-and have been taken-to resolve the problems, while the experts analyze the reasons behind the greater redox potential of white wine.
You can’t have your cake and eat it. Or as they say in French, you can’t have the butter and the money for the butter. It looks as though we can’t have wines that are attractive to taste and drink young yet will make great bottles in the fullness of time. Speaking for myself, I want the latter much more than the former.
I have not come across any significant incidence of prematurely oxidized bottles prior to the 1995 vintage. Since then, some vintages appear to have been more affected than others.
The oxidised-burgs.wikispaces.com website has analyzed the incidence of premature oxidation in relation to individual producers but not vintages, except insofar that Don Cornwell and colleagues have instituted an annual white Burgundy series of dinners to appraise the seven-year-old vintage, that being the point at which they feel premox is likely to be showing. There are headline rates for the proportion of deviant bottles from these dinners, though I feel that the sample is too small and the window too localized for them necessarily to reflect an accurate overall picture.
The following is a rapid survey of my view on where we stand today, with notes on why I think some vintages may be more prone to the pox than others.
1995 A medium-sized vintage considered to be among the better years for white Burgundy but, in fact, often a bit disappointing in both colors. I remember that the leaves turned golden very rapidly in ’95-perhaps a sign that the vine was no longer giving sustenance to the grapes by the time of harvest. Acidity levels were not particularly high, but the grapes were small with thick skins, and the wines appeared to have good aging qualities. I have not personally suffered from many prematurely oxidized bottles, though others have. Domaine Ramonet is understood to have had significant problems relating to their cork supplier. At 18 years old, bottle variation can be expected.
1996 A significant offender. Widely misjudged (mea culpa, inter alia) because of the high acidity at the outset, but in many instances the acidity and the fruit do not seem to have married, with the fruit oxidizing quickly, before the acidity has declined. There is one specific technical explanation for this: The malolactic fermentation was reluctant to happen, and many producers were obliged to leave their wines unsulfured and in a warm part of the cellar to try to encourage the malolactic to take place before bottling. This may well have introduced an element of oxidation into the wine, compounded by inadequate sulfuring at the bottling, since producers imagined that the acidity would do the preserving work for them.
At a tasting with trade colleagues in 2004, we found a very high incidence of faulty bottles even among the very top growers. However, at a tasting in October 2005 for the Solicitors’ Wine Society, only one wine out of nine, and that from a modest producer, showed significant oxidation. In the other eight, there was some bottle variation (a dozen of each were used), but encouragingly, several wines that showed a hint of oxidation on opening cleaned up in the glass.
Many people threw away their ’96s after such a high incidence of oxidized bottles, but though I stopped opening them myself, I couldn’t bear to throw my remaining bottles away. I have started to try them again recently and have not only not suffered any oxidized bottles out of the latest half-dozen opened, but they have usually been absolutely superb-exactly what I was hoping for when initially judging the vintage. Have they come back from a temporary seeming-oxidation, or am I fooling myself?
1997 A very warm September provided ripe fruit with low acidity. The wines were well thought of for their charm and ripeness but not considered as long keepers. 1997 was not a prime culprit for premox, and now normal oxidation is taking over.
1998 An incredibly difficult growing season, especially in Meursault-frost, hail, oidium, an exceptional August heat spike, September rain and rot-led to possibly the least good white-wine vintage of the past 20 years, with many wines out of balance from the start. Many have oxidized quickly, but these were not wines recommended for keeping. A few good wines, though, mostly in Chassagne-Montrachet. Too unbalanced a vintage for it to be clear if premature oxidation is/was at work.
1999 This was a bumper crop that ripened early and well. Even some top growers exceeded the permitted yield, but there was a widespread view that the vines could support a big crop in this early and healthy ripening season. This vintage has been one of the most disappointing for me for premox. One producer told me that because he had exceeded the maximum yield, he discarded all the solids and just vinified the clear juice. Perhaps because of this, he has suffered far more premox in 1999 than any other vintage.
2000 Good sugar ripeness but with an edge of brisk acidity to the 2000 crop, also a large one. There did not appear to be many problems with this vintage, though an edition of Bourgogne Aujourd’hui reported 20 percent of oxidized bottles in a tasting of 98 different white wines from 2000. However, in my experience 2000 has been much less affected than 1999.
2001 A modest vintage, healthy but needing another week of sunshine to make really fine wines. I have tasted a few top white wines that were more advanced than expected, but 2001 is not considered one of the prime candidates.
2002 By this stage, producers were becoming aware of the dangers of undersulfuring their wines, and in any case the structure of this vintage is such that the wines ought to have kept very well. However, there is one caveat: Some producers were bottling their wines in the extraordinary heat of August 2003, and if their cellars were not very adequately temperature controlled at that time, there could be some oxidative repercussions. After 1996 and 1999, this is the third most affected vintage in my experience.
2003 It was initially feared that the wines from this extraordinarily atypical vintage would not survive long enough even to make it into bottle! Picking started in the first half of August, and the general view was that most whites were unbalanced and needed to be drunk very quickly. Indeed, those producers who panicked and bottled early have preserved the instability of this ultra-hot year rather than the fruit in their wine. However, those who held out for a full 18 months of élevage seem to have dropped the unstable elements out with the lees and made more balanced wines that have avoided the curse of premox. Perhaps the thick skins and concentrated juice have provided protective phenolics.
2004 A big crop with various unclean elements such as oidium and rot to destabilize wines made by less fastidious producers. These wines will not be long keepers. However, those who were able to bring healthy grapes at reasonable yields to their presses have made good wines with a middling life expectancy. Interestingly, in a number of cellars there are signs of reductive elements locked into the wines-possibly a residue of the heavy sulfur treatments that were needed on the vines this year. I am not much of a fan of this vintage, and the wines seem to me to be pretty much mature now in the normal course of events.
2005 Growers commented during the harvest that the Chardonnay must was oxidizing very quickly. This may not be a bad thing, however, since it removes the oxidases at an early stage. First tastings showed rich, concentrated wines, sometimes low in acidity. Today, many 2005s offer a whiff of oxidation on first opening. My impression is that there is a trace, sometimes more, of superficial oxidation, with an immense core of very youthful tightly wound fruit that is in no way oxidized but that is not yet open for business either. I am leaving my own cases safely (I hope safely!) in the cellar for a while yet, though it should be noted that the oxidized-burg group had a particularly poor showing from this vintage at their seven-years-on inspection point.
2006 A plump, low-acid vintage that has not suffered badly from premox, excepting a few producers with a heavy track record in this respect, but is now reaching an optimum drinking window.
2007 An early vintage, beginning in August, but the best wines have come from those who held off until the second week of September. There is not the stuffing or structure for long aging, though, and one or two wines may tire relatively early.
2008 More concentrated than 2007, these are wines with plenty of fruit and high acidity, not always married together. Colors were quite deep from the outset, a side effect of the ripening being due more to the north wind than to sunshine, and this may cause some to suspect premox as the wine is poured. So far, however, there do not seem to be many instances, but I don’t find this to be an inherently balanced vintage, so I am expecting variable aging as time goes by.
2009 Our three-years-on tasting (WFW 38, pp.174-85) did show a few wines with a slight hint of potential oxidation problems, with bruised-apple notes to the bouquet. As ever, we have to ask if this is a temporary stage or the start of a rapid and permanent decline. Those who picked early enough should have made powerful, balanced, and stable wines, while those who picked late have usually produced clumsier wines that may not age well.
2010 At our three-years-on tasting (WFW 42, pp.168-81), it was noticeable that many more wines had much higher SO2 levels than we have seen for a long time. Most wines should age well, though there remains a question mark over those with a considerable proportion of noble rot.
A version of this paper first appeared in the Inside Burgundy Annual Report 2014. The editor of The World of Fine Wine is very grateful to the author and to the publishers, Berry Bros and Rudd Press / Segrave Foulkes, for their kind permission to reproduce it here.
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