No. We never add sulfites or any preservatives to our finished vinegars. They are raw and unpasteurized because vinegar is a natural preservative.
It is common, however, for wineries to add sulfites to their wines as part of the wine production process. We do our best to remove those sulfites because sulfites inhibit our bacteria from doing their job during the vinegar fermentation process. That said, there is a chance that some amount of sulfites may be present in our wine and cider vinegars.
All of our vinegars that may have residual sulfites from the alcohol fermentation are labeled with "contains sulfites" on the back label next to the ingredients. You should not use vinegars labeled with "contains sulfites" if you are allergic to sulfites.
Beer and rice wine vinegars generally do not contain sulfites because no sulfites are used in alcohol production.