From wine to vinegar
Vinegar (from the French vin aigre, or sour wine) is made from any wine or alcoholic solution. Wine-making countries, such as France, Italy and Spain, produce vinegar with their grapes just as other countries use native materials, such as apples, coconuts, dates or rice.
How wine vinegar is made
Wine vinegar is made from the twofold fermentation of grape juice. The first (alcoholic) occurs when natural yeasts in the air or on the fruit convert sugar into alcohol. The second (acetous) occurs when vinegar yeasts (also natural but usually added) multiply to form a floating raft of bacteria and yeast cells, called the vinegar mother.
The mother converts alcohol into acetic acid, giving the vinegar its sharpness. Wine vinegar is required to have at least six per cent acetic acid (other vinegar types range from four to 14 per cent), and the best-quality ones are aged in wooden barrels.
How to wine vinegar
Keep open bottles tightly capped in a cool, dark place for up to six months. Though colour changes or sediment may appear, the vinegar is still usable. Most manufacturers pasteurize vinegar to prevent bacteria from forming a mother. If one does form, it's perfectly safe to filter it out.
Red wine vinegar, like wine, gets its colour from grape skins and flavour from grapes and aging. Specialty brands often identify the variety (such as Merlot or Zinfandel) or the wine-producing region (such as Bordeaux or Chianti). Red wine vinegar is usually sharp and full-bodied, making it a good choice for vinaigrettes, marinades and dark meats.
White wine vinegar is made from white wines (such as Chardonnay) and sparkling wines (such as Champagne). It is sweeter, with a more subtle, clean taste than red wine vinegar, making it ideal for mild greens, fish and light-colour sauces.
Champagne vinegar is made from Champagne stock (the wine before it undergoes its second fermentation to produce bubbles). It has a pale colour and delicate flavour with toasty, yeasty notes. Spain's Penedès and Italy's Veneto regions also produce vinegar from their sparkling wines, Cava and Prosecco. These make elegant substitutes for white wine vinegar or a delicate base for fruit-infused vinegar.Things you didn't know about Balsamic vinegar and an ancient Roman energy secret on page 2!