Vinegar is alcohol’s fate, the natural sequel to an alcoholic fermentation. Alcohol makes a liquid more resistant to spoilage because most microbes can’t tolerate it. But there are a few important and ubiquitous exceptions: bacteria that can use oxygen to metabolize alcohol and extract energy from it. In the process they convert it to acetic acid, which is a far more potent antimicrobial agent than alcohol, and came to be one of the most effective preservatives of ancient and modern times. Alcoholic wine thus becomes pungently acidic wine: in French, vin aigre.