Helene's son (Queenofsheba52, posts #2 and 3) , not mine
I had a similar problem with etchall cream - left the bottle at the cold balcony in winter and when I took it and wanted to use to etch some fusing pendants, I got whitish spots, etched spots and some almost not etched spots.
Just try, may be it helps you. The sealed new bottle has longer shelf life than a used one anyway.