Wine left out in the open air will naturally turn to vinegar. How does this happen? Acetobacter bacteria and Mycodermi aceti yeasts accumulate on the surface of the wine, gobbling up its alcohol and turning it into vinegar. Vinegar fermentation requires plenty of oxygen, so it is important to have as much of your wine as possible exposed to the air—an open carafe, jug, or crock will work fine. While vinegar-making microflora will spontaneously gather on your wine, you may choose to kick-start the process with a mother of vinegar culture. This red wine vinegar is flavored with star anise and cloves, and makes an excellent all-purpose seasoning for everything from salad dressings to marinades. This recipe first appeared in our October 2011 issue along with Sara Dickerman's article Preserving Plenty.