How to Treat a Volatile Pinot Ferment

The impact of a volatile Pinot ferment may be minimized by preventing further production of acetic acid.

Making good Pinot wines is a notoriously tricky process. Pinots generally contain lighter proportions of flavorful compounds than other wines, making them more susceptible to a wide variety of wine faults. One of the most common faults in Pinot fermentation is volatility, or excessive amounts of acetic acid caused by bacterial fermentation. Volatility is characterized by a smell and aroma of vinegar, leading to the common term of "vinegar fault." While acetic acid is exceedingly difficult to remove from wine once it is there, a volatile batch of Pinot that has been caught early may be salvaged.

Instructions

1. Control the temperature of the fermentation. Fermentation produces heat, which means fermenting material will always be warmer than the ambient temperature. The bacteria which produce acetic acid thrive at higher temperatures than the yeast which ferments wine. Lowering the ambient temperature of your fermentation room may help curb the production of acetic acid. The temperature of a Pinot ferment can be kept between 83 and 91 degrees F, but should absolutely never rise above 95 degrees.

2. Move up the bottling schedule. Once a batch becomes volatile, the production of acetic acid will continue as long as the wine ferments. Early bottling may sacrifice some of the flavor and subtlety of the batch, but can also limit the vinegar qualities of a volatile ferment.

3. Add sulfur dioxide to the ferment. Sulfur dioxide inhibits the growth of many microorganisms, including the bacteria which produce acetic acid, and is widely used in the winemaking industry. Once a ferment has begun, the sulphur dioxide will kill off some of the yeast as well, so only use it as a weapon of last resort. Most ferments can tolerate about 1 to 2 grams of sulphur dioxide per gallon.

4. Blend the wine with other batches. While volatility is considered a wine fault, acetic acid itself is present in all wine and helps contribute to the complexity of the flavor. By blending small amounts of volatile wine with less flavorful batches, you can salvage the volatile wine while improving the flavor of a bland batch.

Tips & Warnings

• The best method of reducing volatility in a Pinot ferment is prevention. Observe good sterilization practices at all stages of the winemaking process to prevent bacterial infection, and carefully inspect new grapes for signs of disease.

References

• New-World Winemaker: Volatile Acidity in Wine
• Practical Winery: Sulfur Dioxide
• BR Squared: Techniques for Pinot Noir