What can you do with leftover wine, besides drink it? Make vinegar! Drawn from a barrel, it will have a woody flavor and aroma that will be better than anything you can buy. The process is simple; it doesn’t take much labor, but it does take time. Like many simple processes, it must be done carefully and with attention to detail. For example, Bertolli states that vinegar can be made in all sorts of containers, but he strongly recommends an oak barrel, and he tells you how to prepare it for making vinegar. Then Bertolli takes us through the four basic steps of making vinegar: preparing the starter culture, or “mother,” which introduces the bacteria that convert the alcohol in the wine to acetic acid; making the basic vinegar stock, which is a combination of diluted wine and vinegar (a most useful sidebar explains the process, gives a simple example, and provides a helpful how-to chart), after which the mother is added; fermenting, which can take from three to six months; and bottling and aging. (Yes, vinegar, like wine, ages after bottling.) Bertolli also tells us how to test vinegar by smell and taste. There’s a wealth of information in this article: a sidebar has a list of things to look out for when making vinegar; there’s a list of sources for vinegar-making equipment; and a drawing of a vinegar barrel showing both the exterior and a cross-section so that a would-be vinegar-maker can see both the fermenting vinegar and the equipment required to produce it.