White Balsamic Vinegar is made from white wine vinegar made from Trebbiano grapes grown in the Modena region of Italy combined with concentrated, uncooked grape must. White Balsamic vinegar has a light slightly sweet flavor with a moderate amount of acidity about 5.2% to about 7.0% and lacks the rich caramelized flavor of traditional Balsamic. It works well in salad dressings and in any sauce where a red vinegar is undesirable. Don't confuse this with conventional Balsamic vinegar, which is dark red with a concentrated sweet flavor.
Look for White Balsamic Vinegar in well-stocked grocery stores, gourmet markets, and online. But it at Amazon.com: White Balsamic Vinegar, 17 Ounce. There are other brands available too.
If you need an alternative to White wine vinegar you can substitute equal amounts of: