Year old yeast..

What is the longest you would fridge a mason jar of yeast for? I have some that had it's first birthday today.. just wondering if i should toss it, or if it still will have some life in it if i try and revive it in the next month or so..

kthx.

IMO, toss it.

I agree- it's probably best to toss it.

However, I found myself completely out of fresh German Bock yeast for my Maibock during that cold spell, and couldn't order more as I knew it would freeze. I dug out a jar of washed yeast marked 02/08, made a starter and used it. It seemed to have worked just fine, and the beer is now ready to lager. I guess you could open the jar, smell it and see if it smells ok. If it has any off odor (particularly fecal like), then toss it. If it seems ok, then you can decide to use or toss.

if it does smell fine i would do a starter at half normal strength ie 1.020 or so, then bump it up to normal

I'm going to take the opposite tack of my esteemed collegues , on the other side of the aisle (sorry too much cspan since the election )...Except for Erik that is...

I would make a starter and see if it's still viable...My LHBS sells dirt cheap out dated yeast...I've used 6 month old with no problems..



Think about this....many of us harvest yeast from bottles of beer, right? From the last little dregs in a bottle...even in a year old tube or packet there is probably a heck of a lot more viable cells in THAT then in the bottom of a bottled of Rogue Shakespeare stout...

So it wouldn't hurt to try...even if you don't brew right away..you could build up a huges starter of it, then harvest and jar it up for later...

I mean, if you dump it you will never know...and if you toss it into a couple cups of starter wort, you may at least recoup the money you spent on it...and have fun playing yeast rancher.

I just brewed a Kolsch with washed yeast that was 11 months old. I made a 2000ml starter and pitched the 4 pint mason jars I had in the fridge after decanting off the liquid. It took about a day longer on the stir plate to see active fermentation but it really took off.

I pitched the starter to 11.5 gallons of wort at high krausen and saw activity in 4 hours and extreme blowoff at the 24 hour mark. And this was at 57 degrees!

I totally agree with Ravvy. The thing about making a new starter form old yeast is that the dead ones will become irrelevant when the viable ones take over. Just Pitch small into a small starter and step it up. You most likely Will end up with a population very much like what you had before.

What are the odds of you propagating whatever nasties are souring the yeast? For the cost of a bit of yeast I'd say dump it.

Fingers said:

What are the odds of you propagating whatever nasties are souring the yeast? For the cost of a bit of yeast I'd say dump it.

Click to expand...

what souring?

Fingers said:

What are the odds of you propagating whatever nasties are souring the yeast? For the cost of a bit of yeast I'd say dump it.

Click to expand...

If it's in a sealed container, then nothing is "souring" the yeast....there's no mention in the op's post about anything souring it...it's just been sitting in a sealed container not getting used for a year. It's not infection, it's just atrophy more than anything else....

It's like dumping a beer if you think it tastes bad as opposed waiting it out a few and seeing if maybe something good comes of it..It doesn't hurt to try it out...

We're not talking about 5 gallons of precious beer...we're talking, like Conroe said, a small "intro starter," and with luck stepping it up.

If anything the op can answer from experience as opposed to conjecture, the next time this question gets asked...and you know it will get asked again...

But as long as there's a few viable cells, they will reproduce....and it's doubtful that if he properly harvested the cells, and stored them cold, that anything bad is in there...Heck, if you listen to the history of Charlie Papazian's 20+ year old yeast strain (which is now commercially available) it went through a period of infection, and he left it alone for a number of years rather than pitching it out...and overtime the infection died off, leaving the more hardier yeast to survive.

So, it ain't a big loss to test it out, I believe.

There are always going to be bacteria in a sample. You can minimize those levels by following well documented sterilization techniques, but I'm suspecting that a jar of yeast in the fridge doesn't meet those standards. As the yeast dies there will be microorganisms that will feed on the waste and they will multiply. We refrigerate not only to preserve the yeast in dormancy, but to slow down this process. So now that we have a jar of yeast and bacteria, who wins the race when we provide ideal breeding grounds for both? What if it's a tie?

I think some of the calculus has to be, "How valuable is your time".

Unless it's an unavailable strain, it's not worth an hour of flipping burgers.

Fingers said:

There are always going to be bacteria in a sample. You can minimize those levels by following well documented sterilization techniques, but I'm suspecting that a jar of yeast in the fridge doesn't meet those standards. As the yeast dies there will be microorganisms that will feed on the waste and they will multiply. We refrigerate not only to preserve the yeast in dormancy, but to slow down this process. So now that we have a jar of yeast and bacteria, who wins the race when we provide ideal breeding grounds for both? What if it's a tie?

Click to expand...

Well...based on Papazain's story I vote that the yeast wins out...They are pernicious buggers, our friends are...

But neither the OP, or us will know if he dumps it, and doesn't make a starter, right????

So I think he should test it out..and prove us right or wrong...and learn us some things....I'm all for the edumacation....

I suppose that's true, but I imagine he intends to dump it into at least a five gallon batch of homebrew provided it doesn't growl at him when he enters a room. I can't imagine taking that chance.