Opened a bottle last night of a wine I have had before and enjoyed, but this particular bottle was the most (non corked) flawed bottle I have ever experienced. Massive sediment all around the sides of the bottle (this was a 2014) and VA to the extreme, so strong I had to pull back from the fumes. Couldnt get close enough for a taste if I wanted to.
So curious as to what might have happened to this particular bottle to create this much VA? Bacterial contamination of some sort?
This was a recent purchase so I took it back and replaced it, but havent openend that one yet to see if it is a batch issue.
The acetobacter that converts alcohol to acetic acid (assuming that’s the kind of VA you’re talking about) needs oxygen. Hence, if a wine has the bacteria when bottled, there may be bottle variation based on cork variability (of which there is a lot). The bottle’s storage temperature might be a factor, too, since bacteria tend to multiply at warmer temperatures.
Yes, sounds like a flaw in the cork, eg a split along the side, and probably period of warm temperatures. The bacteria are everywhere, so it’s more about the conditions that let them do their thing.
Thanks. I didn’t recall anything unusual with the cork, though I didn’t inspect carefully and it did break in half pretty quickly/easily after I re-inserted once.
Have to say I would rather drink a wine that is both super bretty AND corked than try to drink one like this though. Best use would have been stripping varnish.
From some Australian studies, it appeared that oxygen transmission rates of dry corks (most of the tests used dry corks) didn’t seem correlate well with the variability in performance of wet corks. There was also a study (using a non-permeable epoxy) that indicated the transmission of oxygen with natural corks was mainly around the edges (the interface with the glass) while the transmission with the synthetic corks in use at the time was mainly through the body of the cork.
As others have pointed out, it certainly could be bacterial in nature. But one should then find out whether the wine was sterile filtered or not. If it was, it would minimize the chance of this being the case - unless the entire run showed elevated levels of VA prior to bottling.
Also, are we talking VA here or Ethyl Acetate (nail polish remover)? Folks oftentimes confuse the two - just wondering.
If you are seeing variation from bottle to bottle, ,my guess would most likely be the cork and variability due to it’s natural properties . . .
In my experience, people tend to use VA to mean both acetic acid and ethyl acetate. The bottles I’ve opened that were outliers compared to previous bottles were generally showing a lot of EA. I think it’s difficult for oxygen plus acetobacter to male acetic acid for very long without making ethyl acetate as well. At least for me, the latter is a lot more dominant on the nose.
John, which part was counterintuitive? There are certainly bad corks, just a question whether it’s usually a flaw in the body of the cork or the seal with the glass.
I think new oak barrels are a cause of EA/VA (new oak being more porous and oxygenating)…so I’d suspect imperfect mixing as a cause. This doesn’t necessarily mean bottle variation, esp in higher % new oak barrels, since a bottle doesn’t have to have the exact same % of all barrel to be consistent, just the same % of all barrels ‘in the same category’ (plus other mixing along the way).
I just had an 8-year-old Northern Rhone that had a dark red colour and tasted youngish. When I got to the bottom of the bottle 2 days in the fridge, there was a fair bit of sediment and it reeked and tasted of very old wine - bitter, vegetal and sour. Was that from the sediment? Is that VA?
Lots of microbes around, but not usually so much INSIDE the bottle. Sterile filtering would remove them, and also the pre-bottling dose of SO2 that even some “natural” wines get. It is a lot more common to open a bottle of sherry-like oxidised wine than one that is destroyed by VA. That’s why I called “bacterial infection”. But, yes, you will need oxygen too.
Strictly speaking VA is (mainly) acetic acid. But wherever acetic acid exists in wine there is also ethyl acetate, and that is mainly what you detect. Most wine people seem to use the term VA when they smell ethyl acetate, and I have no problem with that. It seems to me to be overly pedantic to distinguish between the two when talking about wine, as they both exist together.
James Billy - no it was not VA. Nail polish smells of VA. Or at least it did last time I smelled one. Some nail polish REMOVERS also, but they may also be (or contain) other solvents, and have added fragrances - so best to ignore them when figuring out what VA smells like.
Finally… No one has mentioned acetone yet, but it usually crops up. The only reason, I believe, is because it is also sometimes used in nail polish remover. However it is nothing to do with VA, and does not have any significant role in wine chemistry at all.
Why do you rule out acetic acid, Steve? As others have pointed out, the term VA covers a number of compounds.
I’ve found over many years that Rhones, Northern and Southern, develop acetic acid after they’ve been open a few days. There is often a distinct vinegar scent.
That would explain the sourness James reported. Also, I think acetic acid develops first. As I recall, ethyl acetate is derived from the acetic acid, no?
The bitterness in James’s wine, of course, might well be the sediment.
(FYI, I make my own vinegar, and am aware of the difference between acetic acid and ethyl acetate because, if I leave it too long in the barrel, the latter takes over.)
Yes, the same bacteria that turn alcohol into acetic acid in presence of oxygen will also turn acetic acid into ethyl acetate. They will eventually break down the ethyl acetate, as well. That’s why you generally have EA in wine if acetic acid has been produced. It’s also the reason people often pasteurize homemade vinegar if it’s not going to be used quickly. As John mentioned, if you don’t keep adding more alcohol, ethyl acetate will start to dominate over acetic acid in home vinegar production.
For two reasons I would have thought the transmission with synthetic corks would have been around the edges and that natural corks would transmit more through body of the cork: (1) Synthetic closures don’t compress and reexpand as much as cork, so I’d have thought their vulnerability would be where they meet the glass. (2) I’d have thought the synthetic material itself was pretty impregnable and that the irregularity of corks would allow some seepage of air.
On the other hand, as I say that, I know that Diam makes closures with different transmission rates, and I guess they must do that by varying the penetrability of the closure material itself.