Over the past weeks I have had several old top white wines. These all were bought shortly after release and stored properly by me. The fills were still high, and there were no cork or other issues.
Domain de Chevalier (white) 1978. Outstanding. Still fresh, but has smoothed. Some fruit and honey comb character with mineral notes and now smooth acidity. Concentrated with long finish. Shows much better than when younger. It was quite dumb for many years early on and a little raw.
Chablis Clos des Hospices dans Les Clos 1979, #07883, J. Moreau. Still holding well without any signs of oxidation. Outstanding. Light yellow. Was a bit raw and dumb young, but now smooth enough with ample acidity. Complex white fruit and mineral character. J. Moreau made much Chablis in the 1970s that often was not very special. However their Clos des Hospices dans Les Clos was a very special wine and often one of the top Chablis wines of the vintage.
Chevalier Montrachet "Les Demoiselles" 1973, Domaine Louis Latour. Medium bright yellow and no hint of oxidation. First class and likely will hold at least a few more years. Complex with very good balance. This wine often is one of the best from Louis Latour and compares quite well with other top white Burgundy.
Chateau Haut Brion (white) 1979. Medium yellow, clear, and with no oxidation. First class. Long finish. Very good balance. Rather full body for a white Bordeaux. The bouquet is quite complex with complex white fruit and bees wax. The bouquet leads one to believe that the wine might be sweet, but it tastes very dry. In this respect, it is somewhat like a German Riesling Auslese Trocken which can smell sweet but be bone dry on tasting. The wine was quite dumb for many years after the early fruit faded.
Both top white Burgundy and Bordeaux often can last and improve as long as top red Bordeaux in all but exceptional cases such as Ch. Latour in some of the best years. I am not for sure about recent white Bordeaux, but some "top" white Burgundy from the 1990s on is reported to oxidize in as little as a few years. I still have several bottles of white Burgundy from before the problem with more recent vintages was reported. The producers of even many of the "top" white Burgandy wines are doing something very wrong. And I do not think most of the blame comes from cork problems. After all red Bordeaux, German wine, etc. producers do not have severe early oxidation problems, and it is difficult to think that so many white Burgundy producers all have a talent for selecting the worst corks. I suspect that not nearly enough sulfur dioxide is added to many top white Burgundy, and perhaps some white Bordeaux wines now. In fact I would be inclined to reject a young "top" white Burgundy for which one could not smell considerable SO2. The sulfur smell will fade away after a few decades, unless sulfur content is much too high which was the case for many cheap "Graves" wines when I was young. The excess sulfur likely was added to try to correct for poor wine making and poor grapes.