Shelf (fridge) life of potassium metabisulfite

[big_green]

Hi everyone! I finally joined the forum after a couple of months of lurking :rockin:

I have a question about how long potassium metabisulfite should last in the fridge. I made a batch of grapefruit wine from Jack Keller's website about a year and a half ago, and I've had the powder sitting in my fridge since then. I'm planning on making EdWort's apfelwein soon but I was just wondering if anyone would happen to know if the chemical is still potent or if I should plan on buying a new bag.

Thanks in advance, glad to finally be a member! :fro:

 

[captainL]

If its dry it should be good for at least a year or so. I think on winemaking talk there was a discussion and the verdict was that after a year it looses about 10% potency. I've been using the same stuff for over 18 months now...

 

[big_green]

Thanks captainL! I had a feeling it would be alright but I couldn't find any kind of answer to how long the powder would last, only in a solution.