Aceto balsamico by John Spottiswood.

This enormously popular Italian vinegar is prized for its sweet, fruity flavor and mild acidity. It's terrific for deglazing pans, dressing salads and vegetable dishes, and for seasoning everything from grilled meat to poached fruit. Its quality varies enormously. Expensive artisan-made balsamic vinegars (labeled traditional or tradizionale) are aged in wood barrels for at least 12 years and can cost over $100 per bottle. They're exquisitely complex, syrupy and only slightly acidic. Those who can afford them often drink them as they would a vintage port, or use them in desserts, where their sweetness and subtleties can be shown off to best advantage. Cheaper commercial brands are watered down with wine vinegar and artificially colored, but they're fine for most recipes.