I have some Pyrocat HD in glycerol (A&B) concentrates (Photographer's Formulary) that probably haven't been opened since about 2014. I know glycerol extends the shelf life, but does anyone know if this will still be good?
I mix both Parts A & B with deionised water, I find Part A lasts at least 3 years even in a diminishing partially full bottle. Part A in Glycol is even better I have some around 9 years old that I made up double strength because I was taking it by air to Turkey (weight's an issue) saved a Kg that way
I don’t know for Pyrocat but, a few months ago, I opened & tested bottles of PMK Pyro which were at least 8 years old. Part A is rusty red and so opaque that light can get through the bottle. Well, I screwed up and used fresh dev for the after bath but still got negs I could work with. A lot of white dots in the shadows tho, maybe due to all the suspended sediment?
I purchased my Pyrocat HD in glycerol (A&B) 9-24-2014. I'm about half way thru the bottles. Everything is working just fine. Your results may vary, do tests to verify viability.