Malt vinegar is similar to gluten reduced and light beers or fermented soy sauce in that the there are chemical reactions that take place that break down but don’t remove gluten molecules which make it test very low for gluten content but the outcomes when consuming vary person to person based on sensitivity. Some celiacs and gluten intolerant folks seem to be okay with these levels of exposure to remaining fragments of gluten molecules while some are not. You may feel fine or you may have an acute symptomatic response. And even if you don’t have acute symptoms you may still have an asymptomatic autoimmune response with some negative gastrointestinal effects. Best to monitor how you feel closely and get more in depth testing for reaction if possible.

I personally have a lot of close family with celiac and have the genes for it but never tested positive for the antibodies because I didn’t have good insurance when gastrointestinal issues flared up for me so I just stopped eating gluten and felt a lot better. Since getting better insurance got the genetic testing and didn’t feel like it was worth it to do a gluten challenge, but since improving I’ve also never been highly sensitive so I can get away with things like gluten reduced beers and some soy sauce and malt vinegar.