Originally Posted by Cookiebaggs
I used an 11 month old washed kölsch yeast last month. It took about a day longer on the stirplate to get going but it was good. I figured why not try it. I'm only out the cost of the starter if the yeast wasn't viable.
The beer fermented fast and clean. I had blow off at 58º! I washed it again and actually gave a pint to Bernie Brewer (the author of the yeast washing thread) and he made a kölsch the next week that really took off too.
So I guess the answer to how long really depends on trial and error. I usually like to use them within 6 months.
Yep and the kolsch I brewed is about to get racked to secondary, so the yeast is going to get washed again! my jars are in the pot as I type. Thanks again, cookie!
BTW in the last month I have made starters out of Bavarian Lager, and Belgian Abbey II. Each sample was at least 11 months old, and both starters took off after about 24-36 hours, and after brewing with them I'll be able to wash fresh jars of them. So even if your yeast is old, you don't know if it's dead unless you give it a go.