Strong vinegar smell on vintage wedding dress

We recently received a donation of a circa 1950 satin wedding dress. It was stored for decades in a plastic bag inside of a cardboard box and is in excellent condition except it smells strongly of vinegar. I know that acetates have a vinegar smell when burnt or ironed, but do they ever off gas that odor? I haven't yet attempted to burn test and there are no content labels, but I know it is not a silk satin.

I'm hoping that a good airing will help!

 

Yes, acetate rayons can smell like vinegar as they off gas. It's probably noticeable because it was in plastic. Airing out should remove the smell.