Volatile acidity (VA) is a part of all wines. While often negligible, at times it can create issues, or even real problems, in a wine.
The 2022 vintage in Burgundy can sometimes be difficult in this regard, as the pH values are high with some producers. High pH values (3.8 or above) mean that a wine’s stability may be less certain, with high VA and Brettanomyces becoming more likely to cause serious problems.
In other words, the 2022s are in some cases more prone to high levels of VA.
But how does one detect volatile acidity in a barrel sample or bottle?
Measured VA
First, a recent analysis of a wine makes it easy, and you will get a precise measurement.
Some tasters are sensitive to VA, and can sense it even at lower levels; others are tolerant to relatively high levels. Tolerance does not necessarily mean the issue is overlooked, just that the influence of VA is accepted as part of the wine tasted.
VA can in theory be close to zero. But in reality, VA of below 0.5 g/L (of sulphuric acid, H2SO4) is usually not problematic, despite being detectable to very sensitive tasters. But the ability to taste levels as low as 0.2-0.3 g/L is quite unusual in my experience.
When reaching 0.5 g/L, more and more tasters start to become aware of the issue, and at 0.75 g/L, it starts to affect the character of the wine.
The taste
A wine’s taste will eventually be affected by VA, and with a wine at 0.75 g/L, one starts to feel a vivid sensation of nervousness in the wine. More volatile wines might feel forward and openly knit, with a seemingly less tight and focused core. This is where high VA can start to be problematic, as it can blur the expression of terroir.
This feeling will increase as the VA approaches 1 g/L, and at higher levels a distinct sense of vinegar is possible. That said, commercial vinegar has a concentration of 30-90 g/L, many multiples of the acceptable level in wine.
Sensitivity towards VA is markedly different from taster to taster. I – the Winehog – am quite relaxed about VA in some wines, where I can accept levels of 1g/L or perhaps even more. In other wines, I am much less tolerant.
The bouquet
The olfactory signs of a high VA wine reflect the palate, from an opening vivid pinch, through a certain nervousness, and moving on to acetone and ultimately vinegar notes.
Acetone is one of aromas often linked to high volatile acidity. Generally, it’s a sign that bacterial deviation has or is occurring. It may also be linked to the cask.
An old barrel stored after burning a sulphur pastille inside for protection can produce acetic acid, acetaldehyde, and ethyl acetate, if the protection is inadequate. These compounds combine to give the impression of acetone.
In any case, this masks the terroir and, for a technician (trained oenologists), is not acceptable – wheras other tasters find it suitable.
Concerning the level of volatile acidity, acetone can be identified when the VA is above 0.75 g/L, or even much higher if the perception is strong and dominant.
So if you clearly detect acetone, the wine is likely at 1 g/L or even higher, at what is starting to be a problematic level.
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