Volatile Acidity: What is it? and how do I stop it? Volatile acidity (VA) is defined as the steam distillable acids found in wines. Acetic acid is the biggest contributor to VA, but lactic, formic, propionic and butyric acid can also be culprits. Volatile acidity can plague any wine; changing the characteristics of wine from an award winner to vinegar in a matter of weeks. It not only effects the aroma and the flavor, but can also be illegal in high quantities. The bad news is that removing volatile acidity from a wine is costly and not 100% treatable, but the good news is that it is easily preventable.  Let’s start with the basic microbiology to learn exactly what is going on in the wine:  Microbial Level Acetic acid is typically the largest component of volatile acidity, it is caused by bacteria (Acetobacter aceti) that can be found everywhere: grape skins, fruit flies, barrels, and other surfaces in the cellar. The bacteria converts ethanol to acetic acid and produces