From the French vin aigre "sour wine," cider vinegar is made by bacterial activity that converts fermented liquid (cider) in to a weak solution of acetic acid.
Store in an airtight container in a cool, dark place. Unopened, it will keep indefinitely; once opened it will keep about 6 months.
This fruity vinegar is inexpensive and tangy. While it's not the best choice for vinaigrettes or delicate sauces, it works well in chutneys, hearty stews, and marinades. It's also used to make pickles, though it will darken light-colored fruits and vegetables.
Malt vinegar or white vinegar (a good choice for pickles) or wine vinegar (not for pickles)