I have some cranberry juice that developed some dark spots under the lid, is it still considered safe to drink? My mom had some cranberry juice that says best if used in 2018, and was wondering if it will do anything very bad to me, since it was sealed by a reputable manufacturer for this long, and never opened.
Probably corrosion at pinholes in the internal coating ( lacquer type ) and not hazardous. However , I would not take the chance for a couple dollars can of juice.