I've had a small collection of 2007 Louis Latour Corton-Charlemagne that I've been uncorking over the last two years. It is a remarkable wine with a beautiful blend of intensity and finesse -- a classic great burgundy. But, I encountered a surprise earlier this year: the wine was badly -- I mean, badly -- oxidized. I uncorked another one and to my relief, it was fine.

So, was this bad bottle a one-off? When I posted my review on Cellarmaster, other collectors were quick to respond. One said these wines suffered from "premox" or premature oxidation. That sent me back to the internet where I discovered that indeed more and more burgundies were turning up with oxidation.

Wine wines will eventually encounter oxidation if left unopened long enough. A cork just can't withstand shrinkage forever and air gets into the bottle. The wine turns brown and the flavors are more like sherry. But since the late 1990s, the oxidation has been occurring early in burgundies. No one knows quite why, but it is a huge concern for those who have the bucks to cellar expensive grand crus.

To be fair, one needs to be able to identify a premox wine from one that is just aged. An old burgundy -- more than a decade old -- will have nutty, sherry-like character and that's just the beauty of aged wine. However, it should happen in great wines before age 10. That I tasted my 2007 Latour before and after told me that the flawed bottle had indeed turned.