<<Disclaimer: Verify this information before applying it to your situation.>> I looked in my CSA gluten-free products listing for gf mustard. It listed Best Foods Dijonnaisse Mustard as gf but when I read the ingredient label on the bottle I saw it lists vinager- but not the source of the vinager. I emailed BestFoods to verify but they have yet to respond. Can anyone verify that this is really gf? If so what is the source? Thanks Maria