BeerBorg

went to buy white labs yeast this week end from lhbs. the guy pulls out 2 vials, expiration last month. I can let you have 2 of these for the price of one he says. um.. manufacture date of june something? seriously? I declined and bought a fresher yeast vial. I plugged in the old yeast date into a viability calculator and saw that the 2 for one had zero viable cells. zero. I know that is just an estimate and that with a multistep starter I could probably have got some good yeast cheap but why? why gamble and waste dme potentially and time?

would you have gone for the 2 for one "deal"? to his credit though he did mention that there was the risk of some viability issues with the old yeast. I'd like to know why a shop would sit on a product for so long it goes bad if no one is buying it? I would have marked it down 2 months ago and flagged it as a clearance item. write the loss off...

My LHBS sells vials like that for $1.

You can usually make a starter with them and then step up that starter and end up with good yeast. It all depends on if you have a 2L stirplate. For the $ it's worth it.

I don't think I'd go for the 2-1 though. Not cheap enough.

Mine does the $1 deal too but I don't want to take the time for making step up starters. I'm told though they usually do get rid of mist of them,

I recently bought some dry yeast that only has three months left until expiration. But I believe that has a longer life than liquid. I would not have bought 2 for 1 expired liquid. I also bought a couple of cases of 2013 Sierra Nevada Celebration at $4.99@6pack. First I bought a six to taste though, it's still very good.

I would have passed, too. It would need to be really cheap for me to invest the time and DME needed to step it up to a viable size.

When I buy the yeast it usually means I am brewing that day or the next so would have passed. If he would advertise the "deal" rather than wait until someone intent on brewing goes to buy it I am sure he would get takers for those not brewing in the next couple of days so that they can make starters.

Speaking of, what is the shelf life of harvested and/or starter yeast?

Oh, million-dollar question.

I've used 8 month old washed yeast after stepping up a starter but I don't know that I would recommend doing that. As a general rule of thumb, I'd limit myself to 3-4 months, just to ensure I had enough healthy cells to get a good starter going.
Some will say "weeks" is the right answer, though. I'm basing my own timing on experience, not on science so I won't argue anybody's science.

Just realize that out of the lab, WhiteLabs and Wyeast put a 4-month date on their own super-clean yeast.