White distilled vinegar is a neutral flavored acid ingredient intended for pickling or for when you wish the flavor of your vinaigrette to come from other ingredients. Virtually any other vinegar will be a flavor contributor, and the choices are myriad. Wine vinegars are made from practically any grape varietal and in every wine region of the world. Cider vinegar, probably the most popular fruit vinegar, is only the beginning. Berries, stone fruits, tropical fruits and any others that have a significant acid content can be fermented or macerated to create a flavorful vinegar.
Grains are also a source of vinegar, rice and malt vinegars being the most popular.
Aging of any type of vinegar, especially in wood, adds a roundness and complexity of flavor exemplified by the world famous balsamic vinegar produced in Modena, Italy. Oils are somewhat less likely to be a flavor ingredient since so many culinary oils are produced for their neutral flavor. On the other hand, there are many high quality, high flavor oils to choose from. Olive oil is probably the most prominent oil in this high flavor category. Because of its growing popularity as a key ingredient in a healthy diet, chefs have more types of olive oil available to them than ever before.