Derived from the French vin aigre, "sour wine," vinegar is made by bacterial activity thats converts fermented liquids such as wine, beer or cider into a weak solution of acetic acid (the constituent that makes it sour). Vinegar has been used for centuries for everything from beverages (like shrubs), to an odor-diminisher for strong foods such as cabbage and onions, to a hair rinse and softener. There are a multitude of vinegar varieties available today. In the United States, the most popular styles are the fruity apple cider vinegar, made from fermented apple cider, and the rather harsh-tasting distilled white vinegar, made from a grain-alcohol mixture. The French prefer pleasantly pungent wine vinegars, which can be made from either red or white wine. In Britain the favorite is mild malt vinegar, obtained from malted barley. The exquisite Italian balsamic vinegar, made from white Trebbiano grape juice, gets its dark color and pungent sweetness from aging in barrels — of various woods and in graduating sizes — over a period of years. It should be noted that many balsamic vinegars contain sulfites, which are primarily added to inhibit the growth of unfavorable, flavor-detracting bacteria. Herb vinegars are made by steeping fresh herbs such as dill and tarragon in vinegar. Popular fruit vinegars include those made with raspberries and blueberries. Mild and slightly sweet rice vinegar, made from fermented rice, is widely used in Japanese and Chinese cooking. It's a key element in dishes such as sushi. Cane vinegar is made from sugarcane and has a rich, slightly sweet flavor. Vinegar is essential in making pickles, mustards and vinaigrettes. It adds a jolt of flavor to numerous sauces, marinades and dressings, and to preparations such as sauerbraten, sweet-and-sour dishes and marinated herring. It's also widely used as a table condiment for dishes such as England's fish and chips. Vinegar should be stored airtight in a cool, dark place. Unopened, it will keep indefinitely; once opened it can be stored for about 6 months. See also mother of vinegar; su.