It's been cold here in San Francisco, so we haven't been eating a lot of salads these days. I haven't used my red wine vinegar for probably about six months, but when I did need it this past weekend I noticed a solid white block covering the top layer, At first I thought it was frozen. It has been cold but not that cold. The best way to describe it was like a layer of fat that forms once stock is refrigerated, only stark white.
I shook the bottle hoping this would just disolve into the vinegar but it never did. It did disloge and sink to the bottom, I did use it but my dish didn't turn out as good as it usually does, so I wonder did my vinegar "go bad"? It was an organic brand, but I don't know if that makes any difference.