I've had washed yeast that was still viable after 6months or even 9months, however 12month old samples did not revive in a starter.weiht wrote:I have a jar of rinsed wlp001 in the fridge for 2 mths, and I'm wondering how long can it last assuming I still do a step up starter every time? What is the rule of thumb for viability? 6 mths?
Likely it depends on the yeast strain and other factors, but you should be right for 6 months at least.