Vinegar is accepted as gluten free by major celiac disease centers and support groups. In the United States most distilled white vinegar is made from corn. And even when it is made from wheat, which does happen often, the distillation process removes the gluten protein. Donald Kasarda, Ph. D., a grain scientist who is now retired from the USDA and who has a specific interest in gluten free grains, said there is no scientific evidence for gluten peptides in vinegar. Further, he said he does not know of a single chemist who thinks there are gluten peptides in distilled products.
Malt vinegar however, is made from barley and more importantly is fermented and not distilled so you do have to avoid it.