Vinegar is a product of the same fermentation process used to make wine, beer and liquor, in which bacteria and yeast convert carbohydrates in fruits and grains to sugar and then to alcohol. If the alcohol is then allowed to ferment further, the result is vinegar. White vinegar is made from corn; wine vinegar from grapes; apple cider vinegar from apples. The uses of vinegar are legion, and many go back centuries. But they're not just folk medicine; they are backed up by credible scientific research. Apple cider vinegar in particular has received a lot of attention as of late for a multitude of uses, from chronic pain management to gardening to pet care.