[brewmasternpb]

Has anyone bought the discounted yeast at the LHBS?  You know, the liquid yeast that's past it's shelf life?  I've been brewing for 11 years and I've always avoided it.  Today, I gave it a shot.  I'm brewing a Saison, and I already have a pack of the Belle Saison yeast, but there was a vial of the white labs Saison blend in the discount pile.  I figure that my cell count is fine with the dry yeast, I would try the Saison blend, just for added complexity.
When I got home, I plugged the yeast (by manufacture date) into the Mr. Malty calculator.  This yeast had a "best before" date of 9-22-13, which means it was manufactured on 5-22-13.  The calculator had it at 10 percent viability, but it appears that 10% is as low as the calculator goes, so it could be less.  The thing that gets me, the yeast was only 25% off!  With such low viability, it should be 75% off.  Anyway... Lesson learned, stay away from the bargain bin.

[cornershot]

My lhbs gives me the expired yeast for free. I check out the expired bin every time I'm there and have the ok to help myself to whatever interests me. It's usually expired no more than a month and I'm a couple stepped starters away from an adequate pitch. The actual viability depends on yeast strain, storage conditions, etc. and could be much higher than the 10% default viability on the calculators.
I would say that, considering the work and possibly dme required to grow it up, 25% off is not a good deal. It should be kicked down or discarded if it's expired.

[reverseapachemaster]

Probably not the best deal but if you've ever try to get activity out of old yeast from your fridge then you know even at 5-10% viability and some patience you can reach pitching quantities and no problems fermenting your beer.

[weithman5]

i made starter out of a vial of lager yeast (i have pictures somewhere of the type) that was over a year old when i opened it.  was no issue

[majorvices]

I used to get expired or close to expired yeast from my lhbs as well and made starters and never had an issue.

[a10t2]

When I got home, I plugged the yeast (by manufacture date) into the Mr. Malty calculator.  This yeast had a "best before" date of 9-22-13, which means it was manufactured on 5-22-13.  The calculator had it at 10 percent viability, but it appears that 10% is as low as the calculator goes, so it could be less.

That's a serious over-estimate for cell loss, IMHO. I think a better rule of thumb for fresh yeast stored properly is 10%/month, which would put it around 20% 50% viability at this point. Even at 25%/month it's still 20% viable.

[brewmasternpb]

I guess that was one of my questions... Is the Mr. Malty calculator off?
Guys, thanks for all the info!  What I gather from your feedback is: A) I can get good results from old yeast,
2) If I can get brand new yeast for $1.50 more, it's probably safe to by the freshest I can find.

[Slowbrew]

I've only knowingly used expired wyeast packages once (I don't always look).  My LHBS didn't have the yeast I was looking for in the fridge.  I asked the youngin at the counterif they had any in back and he said nope.  The owner heard the conversation and came out of his office with 3 partially swelled packs of the yeast I wanted.  They were old and he was going to toss them so he gave them to me for free.  I threw them in a starter and they took off like normal.  I likely way over pitched that batch.  Long story, short, the yeast survive longer than we think they will.

Paul

[denny]

I've successfully revived and used a smackpack that was 3 1/2 years old.  Although I don't recommend doing that, it's certainly not impossible.  At the moment, I'm boiling up some starter for for a pack of 1056 dated 1/17/13.  I expect it to work fine.

[dmtaylor]

I've been burned by expired yeast several times.  I will revive and use yeast up to about 9-10 months old, but I won't buy it that old anymore.  Beyond that, it is down the drain.

[Jeff M]

most LHBS are allowed to return expired yeast every quarter or so, hence the poor discount.  why people give it away only makes me assume that you are a valuable enough customer that 3-4 bucks loss isnt an issue since you buy all your ingredients from them anyway.

[swampale]

I found that I spent more on DME trying to step up old yeast than if I just bought a fresh vial/pack. Never again.

[reverseapachemaster]

I found that I spent more on DME trying to step up old yeast than if I just bought a fresh vial/pack. Never again.

I run off a little extra runnings on each mash into a separate kettle and boil it down to around 1.080. I shove it in some tupperware in the freezer to use for starters. Dilute to 1.040 and give it a quick boil. Virtually free starter wort. I guess it isn't an option for extract brewers so in that case probably cheaper to buy the fresh yeast.

[brewmasternpb]

The funny thing is that, a pack of the dried Belle Saison yeast was still cheaper than the discounted liquid yeast... at a much higher cell count.

[dkfick]

The other thing besides viability to look out for is mutation that will occur on older yeast.  That older yeast you step up may or may not behave as you expect.