Reducing volatile acidity in wine can be a challenging task for winemakers, but there are several methods that can be employed. One of the most effective ways to reduce volatile acidity is through the use of reverse osmosis (RO).
Reverse osmosis is a process that involves the use of a semi-permeable membrane to separate undesirable components, such as acetic acid, from the wine. The wine is passed through the membrane, which allows only certain molecules to pass through, effectively removing the acetic acid. This process can be especially useful in higher-VA wines, where the acetic acid concentration is greater than or equal to 0.7 g/L.
However, it is important to note that reverse osmosis is not a standalone solution. After the acetic acid is removed through RO, the wine may have a lower volatile acidity, but it may also lose some desirable characteristics and flavor compounds. Therefore, it is common practice for winemakers to blend the RO-treated wine with an uncontaminated and lower-VA wine.
Blending allows winemakers to restore balance and complexity to the wine, while also reducing the overall volatile acidity. By carefully selecting the blending wine, winemakers can add desirable attributes and enhance the overall quality of the final product. The blending process requires a keen understanding of the wine's composition and flavor profile, as well as the desired outcome.
In addition to RO and blending, winemakers may also employ other techniques to reduce volatile acidity in wine. These include:
1. Acidification: Adding tartaric acid to the wine can help to reduce the overall volatile acidity. However, this method should be used with caution, as excessive acidification can negatively impact the wine's balance and flavor.
2. Malolactic fermentation: This process involves the conversion of malic acid into lactic acid by certain bacteria. Malolactic fermentation can help to reduce volatile acidity while also imparting a smoother and more rounded mouthfeel to the wine. It is important to note that malolactic fermentation is not suitable for all wine styles and should be carefully monitored to avoid unwanted flavors or spoilage.
3. Oxygen management: Volatile acidity can be exacerbated by excessive exposure to oxygen. Proper handling and storage techniques, such as using inert gases or tight closures, can help to minimize the risk of increased volatile acidity.
4. Temperature control: Fermentation temperatures that are too high can promote the growth of acetic acid bacteria, leading to increased volatile acidity. By closely monitoring and controlling fermentation temperatures, winemakers can help to reduce the risk of excessive volatile acidity.
It is worth mentioning that the specific approach to reducing volatile acidity may vary depending on the style of wine being produced and the desired outcome. Winemakers often rely on their experience and expertise to determine the most appropriate method for each individual situation.
Reducing volatile acidity in wine is a complex process that requires careful consideration and a range of techniques. Reverse osmosis, blending, acidification, malolactic fermentation, oxygen management, and temperature control are all methods that can be utilized to help reduce volatile acidity and improve the overall quality of the wine. By combining these techniques and applying them judiciously, winemakers can achieve a more balanced and enjoyable final product.