I just opened two bottles, one after the other, of 2001 Mt. Eden West Slope Chardonnay, both of which are exhibiting the most classic case of secndary fermentation I have ever seen - they are virtually sparkling wines!

These wines came from the same batch I purchased over a year ago, and the other 6 or 8 that we opened right away showed no such signs whatsoever. What's going on here? Is it typical for secondary fermentation to start up after the wine has been at rest for some time?

I seen this a couple of times. Usually with a wine that either didn't start or didn't finish malo. For some reason the wine starts up again in the bottle. From what I understand, malo is both temperature and Ph sensitive, so a change in either might set it off.

Well, I called the winery - they were not in the least surprised. She said they had had trouble fermenting this dry, and that there was some residual sugar left in the bottle. Said this was not a wine to be held (sheesh, not even for a year?).

Oh well.

My thoughts exactly - they basically had the position it was my fault for holding the wine

Eric,

If the reaction was a result of the residual sugars in the wine, technically we're not speaking of a secondary fermentation, althought the same bacteria are at work, but of a something that in spanish is called 'picado lactico'. I cannot for my life remember what that is in english. It means that lactic bacilli attack the sugar instead of the malic acid in the wine, which, in case the bacteria are heterofermentative whic ususally is the case, causes carbon dioxide and generally some rather off-putting flavours.

This is a fault that to the best of my knowledge can be avoided with sufficient pH, alcohol or SO2. It is a fault in winemaking, and trying to put the blame on your for keeping it too long is absurd.