Volatile

Volatile wine refers to wine that has excessive levels of volatile acidity (VA), which is commonly caused by the main component, acetic acid, and is a frequent wine fault in various wine styles. Volatile acidity in wine is a specific fault that can affect aroma and flavor, and is closely monitored in winemaking. While all wines contain some volatile compounds as natural byproducts of fermentation, alcohol—specifically ethanol, the primary alcohol in wine—is susceptible to oxidation. When these levels become too high, the wine is considered “volatile” or faulty.

The main culprit is typically acetic acid (vinegar), which forms when wine is exposed to oxygen in the presence of acetic acid bacteria. Ethanol is converted to acetic acid through oxidation, especially when wine is exposed to air during production or storage. Ethyl acetate, smells like nail polish remover, often accompanies high acetic acid levels.

Wine can become contaminated by acetic acid bacteria if poor hygiene is used during production. Regulatory thresholds set legal limits for volatile acidity in wine, and excess VA above these limits is considered a fault. During bottling, transferring wine from barrel to bottle is a critical step in minimizing air exposure and preventing further oxidation.

Characteristics

Wines with high volatile acidity display several telltale sensory markers:

Aroma and Flavor:

• Most people can detect a sharp vinegar smell on the nose, and this smell is often the first indicator of volatile acidity.
• Nail polish remover (acetone-like) aromas
• Sour, tart, or biting taste that feels unbalanced
• In extreme cases, the wine tastes more like salad dressing than wine

Mouthfeel:

• A prickly, almost burning sensation is perceived in the mouth, especially on the palate.
• Sharpness that overwhelms the wine’s fruit character

Acceptable Levels: Small amounts of VA (under 0.7-0.8 g/L) can actually add complexity and lift to wine, particularly in certain styles such as Amarone or some natural wines. However, once levels exceed regulatory thresholds (typically 1.2-1.4 g/L depending on the region), the wine is considered defective.

If wine is stored in a warm environment, volatile acidity can increase rapidly, leading to more pronounced faults.

Not everyone perceives volatile acidity faults in the same way, as individual sensitivity to these aromas and sensations can vary.

Detection

One of the most common problematic faults is volatile acidity, primarily caused by acetic acid bacteria. The bacteria thrive when wine gets exposed to oxygen, producing acetic acid and ethyl acetate—compounds that can give off those unmistakable strong aromas reminiscent of nail polish remover, nail varnish, or even paint thinner.

Winemakers rely on a combination of sensory evaluation and laboratory analysis to spot these faults early. Sensory evaluation involves carefully smelling and tasting the wine to detect any off-aromas or flavors, such as those sharp, vinegary notes or the chemical scent of ethyl acetate.

Detection is critical in white wines and natural wines, where the absence of sulfur dioxide and minimal intervention can make them more susceptible to volatile acidity. In red wine, the presence of tannins and other complex compounds can sometimes mask these faults, making laboratory tests—such as measuring volatile acidity levels using gas chromatography—an essential tool.

Sweet wines are particularly prone to high VA, as their sugar content provides an ideal environment for acetic acid bacteria to flourish. Regular monitoring of volatile acidity levels helps winemakers to detect problems before they escalate, allowing them to take corrective action. In many wines, a small amount of volatile acidity is naturally present and can even add complexity.

Prevention is absolutely key in managing wine faults. Many winemakers focus intensively on controlling oxygen exposure throughout the entire winemaking process, from harvest to bottling, to limit the activity of those troublesome acetic acid bacteria. The use of sulfur dioxide is another common strategy, as it helps inhibit both acetic acid and lactic acid bacteria. Good hygiene in the winery, careful handling of grapes, and regular cleaning of barrels and equipment all play crucial roles in reducing the risk of contamination.

When faults do occur, techniques such as reverse osmosis can help reduce volatile acidity, while blending with unaffected wines can dilute the impact of faults. Sterile filtration is often used to remove unwanted bacteria and yeast, especially after malolactic fermentation, which can sometimes introduce sour or cheesy notes if lactic acid bacteria are not properly managed.

Ultimately, the presence of volatile acidity and other wine faults is a challenge that winemakers face. By combining exceptional sensory skills with rigorous scientific analysis and by maintaining strict control over the winemaking environment, they can produce wines that are both expressive and completely free from unwanted faults. Regular tasting, monitoring, and proactive management in the cellar ensure that the wine in your glass is a true reflection of quality and craftsmanship.

Conclusion

Volatile wine represents a winemaking fault that occurs when beneficial fermentation compounds cross the line into excessive territory. While tiny amounts of volatile acidity can contribute complexity, high levels create an unpleasant vinegar-like character that mars the wine’s quality. Proper cellar hygiene, sulfur dioxide management, and minimizing oxygen exposure during winemaking are key to preventing excessive volatility.

Wines can also become contaminated by bacteria or fruit flies if proper hygiene and storage are not maintained. For consumers, learning to recognize the sharp, acetic characteristics of volatile wine helps identify flawed bottles and understand the delicate balance winemakers must maintain.