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Any issues using 1 1/2 year old yeast

I had an issue with a smack pack I recently purchased. Was 6 months old and would not inflate. I did have a quart of 1.5 year old harvested wyeast 1335. I made a 1500 ml started and added about 75ml of yeast to it. 36 hours later it started chugging away.

Would there be any concerns in using this yeast if I were to decant and make 1-2 more 1500 ml starters with it before pitching?

You might want to make your next starter more beer like (hops in the boil) and ferment in cool like a real beer. Then taste it to see how it is before going with a full 5 gallons.

I wouldn’t have any concerns. As long as you’re sure it’s clean with no bugs that shouldn’t be there there wouldn’t be a problem. Just raise it enough to pitch.

I think you are rolling the dice a little bit - I only say that b/c I harvested some US05 in Feb '12 or so, made a starter in Aug '12 for a lowish gravity wheat and got a random medicinal phenol. I have literally ruled out everything else in the process it could have come from, and when I told some people on the AHA forum, they were pretty appalled that I used such old yeast.

Having said that, I have done this and had good results in the past. The risk is that the yeast can mutate with such long storage if its not on a slant (I’m guessing you had it in a vial in the fridge?)

As some others have suggested, taste it. It might be a bit sour as you didn’t add any hops (and british yeasts can have that flavor profile), but if it tastes ‘clean’, then maybe step up again and pitch some of the slurry (definitely decant the spent starter off it). Maybe grab a pack of S-04 or Notty just in case.

[quote=“Pietro”]I think you are rolling the dice a little bit - I only say that b/c I harvested some US05 in Feb '12 or so, made a starter in Aug '12 for a lowish gravity wheat and got a random medicinal phenol. I have literally ruled out everything else in the process it could have come from, and when I told some people on the AHA forum, they were pretty appalled that I used such old yeast.

Having said that, I have done this and had good results in the past. The risk is that the yeast can mutate with such long storage if its not on a slant (I’m guessing you had it in a vial in the fridge?)

As some others have suggested, taste it. It might be a bit sour as you didn’t add any hops (and british yeasts can have that flavor profile), but if it tastes ‘clean’, then maybe step up again and pitch some of the slurry (definitely decant the spent starter off it). Maybe grab a pack of S-04 or Notty just in case.[/quote]

I am assuming that in order to mutate, the yeast would have to be active and growing. They were stored at 38 degrees in a sealed mason jar in a refrigerator. If the yeast were not active, how could they mutate??

Maybe I misstated that. I think that you have a greater chance of mutation at different stages (ie your starter or your target beer) with old yeast as there are fewer viable cells and they are forced to grow more quickly.

There was a thread on one of the other forums about someone using old yeast (after step ups) and having great results. I think he even did a split batch, one with the old yeast, one with fresher/more viable of the same strain.

I’m just a little gunshy to do this with my results from this wheat beer (my starter did smell pretty sour). I literally went though my whole process, and none of the people on the forum could think of anything else. That being said, it could be a false positive.

Brew on, brewer.

[quote=“Pietro”]Maybe I misstated that. I think that you have a greater chance of mutation at different stages (ie your starter or your target beer) with old yeast as there are fewer viable cells and they are forced to grow more quickly.

There was a thread on one of the other forums about someone using old yeast (after step ups) and having great results. I think he even did a split batch, one with the old yeast, one with fresher/more viable of the same strain.

I’m just a little gunshy to do this with my results from this wheat beer (my starter did smell pretty sour). I literally went though my whole process, and none of the people on the forum could think of anything else. That being said, it could be a false positive.

Brew on, brewer.[/quote]
Okay,
That makes that stressed yeast may mutate. On the other hand, may it also be possible that those that survived 18 months may be more hardy and produce yeast that have a longer “shelf life”???

I think you are totally fine using yeast that old as long as you are very conscious of how you treat them. I’ve used 10 month old yeast that produced great beer.

Making a 1.5L and then a 2L, you could have enough yeast for a 1.070 beer.

Usually when I use really old yeast, or even dregs from a bottle, I will make low gravity starters, like 1.020 instead of 1.040. This gives the yeast a chance to reanimate slowly, lowering mutation. Then I’ll go with the 1.040 starters when I have built up enough yeast.

What about this Not to steal your topic. Ordered a kit for a friend back in march he received it never brewed it and asked me if i wanted it last week. He brought it up to my work and when I looked at the box i had to laugh because he never took the liquid yeast out and put it in the fridge like it says in bright orange on the sides of the box. I pulled it out and threw it in the fridge it was inflated of course. Do you think that It would be ok to use or should i just toss it? of course I will make a yeast starter with it. I have been trying to decide what to do.

Ha…I’d use it if the starter works out. Probably on a low grav pale or bitter, though.

this. Wimpy starter worts give them a nice stepping stone to build up as there is no way you can be sure of viability.

Also, correction to my last post. I was just listening to a Jamil show where he and Tasty said that cold-stored yeast would be LESS likely to mutate.

So, the reality is, I’m not sure what happened to my wheat beer. The other potential culprit is I was trying out BIAB and I didn’t wash or boil the bag (purchased from a custom-made BIAB maker) before I used it and it may have had a chlorine or chloramine-based cleaner on it (haven’t had the flavor in other batches used with it).

You guys speak of mutation as if it’s a global occurrence. Even if it does occur it would be individual cells that are outnumbered about a billion to one by not mutated cells. Also the whole slant doesn’t mutate while liquid yeast does while all being in the fridge is just nonsense. If your yeast isn’t contaminated you’ll have no problem reviving and using it.
For what it’s worth, I revived 5 year old yeast and it works just great. You need to give the little dudes time to wake up and multiply though.

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