I have used some 5-6 month old stuff with no problem.. I have had one jar that went bad after about 6 mos.. stunk like hell when I opened it and after several days I had nothing in the starter.
good to know! I think I'll be doing this the next time I use a $10 wyeast
I save my yeast in White Labs vials, and a fellow brewer does the same. I was out of WLP400 (Belgian Wit), so I asked him if he had some he could lend me.
The vial he gave me was from April, and I just made a starter tonight, since it was so old I made a 1 liter starter, opposed to the 2 liters I normally start with.
I'll step it up to a 4 liter starter, chill/decant, pitch half, make another 4 liter starter, chill/decant, and add 1/2 of the yeast to two vials with sterile water. This way, I'll have WLP400 for a future brew!
Anyhow that was an off topic tangent, but might give you an idea of how to keep yeast on hand for a bit, at least out to 5-6 generations, a $7-8 vial/smack-pack, with some planning can save you $100's, literally.
Regardless, the 8 month old vial that I cracked open today was active after leaving it out for a couple hours, when I cracked it open, ther was a hiss, and co2 bubbles, so I'm confident my starter will be fine with a couple of step-ups.
It just goes to show, that even after 8 months washed yeast can still be good.
Having said that, I did throw away a shot ton of washed yeast that I had in my fridge for well over a year, it had the gray layer of death sitting on the top of the cream colored yeast. Not to say that I couldn't make a viable starter out of it, I was concerned aboutyeast mutationand what have you, I was probably paranoid, but the yeast eas old, I didn't wanna chance it.