Until the 1996 vintage, you could count on enjoying premier cru white Burgundy from around 6 or so years after the vintage to well over a decade, and you might start grand crus after 7 or 8 years and enjoy for another decade. Then everything changed abruptly, and wines began to show levels of oxidation after only three or four years: the color would darken, the aromas would resemble Sherry, and the palate would seem to dry out.

No one knows why premox started so suddenly. The first wines I experienced it with were from the 1996 vintage. It was random, with some bottles just fine while others from the same case were affected, and some producers seemed to have less problems than others, but I’ve subsequently had examples even from the producers who seemed immune. It’s been a disaster for anyone who prizes old white Burgundy, with the window for enjoying the wine really foreshortened.

What was most puzzling was that it seemed to affect everyone in a random way. As the problem has continued over the years, it’s become apparent that there isn’t any single, simple explanation. It seems to have been a perfect storm with many different factors contributing. Dominique Lafon has been a leader in looking for solutions. While there are still some producers who deny the severity of the problem, Dominique feels it should be addressed head on, although he points out that people often confuse natural aging with premature oxidation. “They open an old bottle and say it’s oxidized, but if you open a 1996, it’s not premature oxidation, it’s the aging process.” He sees the problem as resulting from the accumulation of many factors and has been taking a very scientific approach to pinning them down one by one. “It’s no use changing everything at once,” he says “because then you don’t know what the critical factors are.”

A morning at Comte Lafon ended with a wonderful tasting of his range of premier crus from 2012 and I’ll discuss the changing style of Meursault in a later post, but now I’ll report just on the conversation in which I asked Dominique about the factors that have been associated with premox.

How much of a problem have you had with premox? “The first vintage I really saw problems with was 1999; what puzzled us was that it was very random. The first thing we thought was that we had cork failures – I think we did – but it was showing the fragility of the wine. We started by working on the corks, we asked them to stop the peroxide treatment. (Peroxide, which is a strong oxidizing agent, was introduced to clean corks to avoid treating them with chlorine, which was causing the increased levels of TCA responsible for corked wines.) We went back from silicon coating to paraffin (which makes a better seal).”

“Then I worked on the reduction level, we’ve experimented with the amount of lees we trap – a wine that is more reduced will withstand a small cork failure. We worked to get the right amount of lees that would give just that nice level of reduction. In 1999 we had a huge crop, I was looking for space, and so we had used less lees.”

Is battonage a factor? “My father did a lot but I’ve never done much.” What about racking? “We do at least 18-20 months in barrel, but in the summer we move from young to older barrels, we used to do it with air, and we used to get rid of some of the lees, but I don’t use air now and I keep all the lees. We want to have more carbon dioxide in the wine, which is very protective. And of course raising the sulfur level is easy. The future work will be to get the sulfur level lower.”

Has the problem been fixed? “We are close now. All those things were done by 2007-2008, and in 2009 I met with Denis Dubourdieu and we did experiments here and at Roulot on the pressing. We worked to get more glutathione (an indication of reduction) and less sotolon (an indication of oxidation). By splitting the pressing and leaving 20% at the end we do better, and then we oxidize the last part fully. And we start fermentation in stainless steel tanks, which makes it more precise.”

“At assemblage tanks are flushed with nitrogen before filling. We bought a machine to generate nitrogen, because you have to flush the tank four times, and the bottles of nitrogen aren’t enough and are expensive.”

“We follow the dissolved oxygen all the way through. We know 1 mgm dissolved oxygen will absorb 5 mgm free sulfur. At the lab, people are satisfied when they get 2 mgm dissolved oxygen in the wine, but we are at the point where we have 0.5 mgm before bottling and it might go up to 0.8 mgm after bottling.

“We use special bottles that allow dissolved oxygen to be checked at bottling. Since 2009 we’ve brought the wine back to the lab after 8 months to check the sulfur levels and carbon dioxide and to taste. We bottle with free sulfur around 35, when we check after 8 months it’s always 28-33, we think 20 would be enough.” We walked around to look at the bottling machine. It has some sophisticated additions to vacuum the air out of the bottle and to inject nitrogen.

What about using other closures? “I’m pretty sure that with time everyone will use technical corks. Diam (a cork that’s been treated to eliminate problems with TCA) is more consistent. I’m amazed, it’s always slightly more reduced when you compare in tastings. In terms of seal, Diam will do the work, but we don’t know whether it will get into the wine long term.”

Even in the premox era I’ve had some fantastic old white Burgundies – well, to be honest, it wasn’t intentional, they were in my cellar and I forgot about them, and by the time I found them some were shot, but the best from the late nineties were as brilliant as ever. (I have not done so well with the 2005 vintage whichseems to be aging more rapidly than usual.) I’ve tasted many wonderful wines in Meursault and in Puligny Montrachet this week – reports coming up in later Diaries – and I just hope that the problem has been resolved as these wines all strike me as awfully young, and I’d like to look forward to enjoying them at the peak, maybe a decade or more from now.