Almost 3 year old yeast slurry

Found it in my refrigerator. WY-3333 yeast. As I was typing this I realized it was 3 years old and not 2 and edited the subject line. January 2017.

Do you think it might still be alive? It has not discolored any, and there's nothing floating on top. Just clean white packed-down yeast (it must be from the secondary) with a layer of flat beer on top. If it was a dried yeast variety I would throw it out. (I was throwing out old but not *that* old K-97 and T-58, etc when I found this one.)

Since it doesn't seem to be contaminated, I think I'll try to wake some up and see what happens.

 

How do you know it’s not contaminated? Not much is gonna happen at fridge temps if it is contaminated.

Did you open it and smell it? I’d bet almost everything is pretty dead.

I’d take a very small amount of the yeast and very gradually step it up, starting with a very small/low OG wort.

Actually I would t bother but if you were to that’s what I’d recommend.

 

Flag porter is fermented with yeast salvaged from an 1825 shipwreck.

 

Only one way to find out! Spin up a starter and see what happens. Or you can throw it out and always be wondering.

 

And beer, wine, and bread have been fermented with yeast recovered from pots thousands of years old. But all of those cases require isolating a single cells in a lab, culturing them up, and eventually -- if anything grows at all -- determining whether the cell was a usable yeast or a contaminant or mutant. It can be, literally, a one in a million thing. You don't just put the whole sample in wort and grow up a starter.

 

I wouldn't necessarily assume that it is contaminated - but I wouldn't assume it isn't, either.
Depending on your handling when putting it away it could be, though.
However, it's still good enough to try a starter.
I would make it lower than usual, and make sure you use yeast nutrient in there.
Start low gravity, step to usual, presuming everything goes well, then to the usual step up procedures.

 

I have revived yeast slurry well over a year old. WY3333 seems interesting would be worth a shot to try and revive it. WY3522 drops pretty clear might work in place of WY3333 if it is dead.

Some very old yeast, my mailman said one of the guys in this story was on his route and had tried the beer when it was first release.
https://www.sfgate.com/food/article/The-East-Bay-beer-that-s-45-million-years-old-9177673.php
http://www.fossilfuelsbeer.com/thestory

 

How much dme and time do you want to spend to possibly rebuild? Personally I would just buy another pack of yeast and start over.

 

I want to see if it's alive and salvageable even if I never actually use it Especially now that I realize it's 3 years old and not 2. All I have is DME and time

 

It's no more contaminated now than it was 3 years ago when I put it in the fridge and forgot about it; the jar was sealed. I figure the cold and the alcohol from the beer on top is more hostile to bacteria and other fungi than to the beer yeast. The yeast hasn't discolored any, and the is nothing floating on top. So I assume it's still reasonably pure, but it might not still be alive. I will find out this week. I have not opened it to sniff it yet; I don't want to get boogers in it. (or dust, or whatever)

 

If it's brown, DRINK IT DOWN! If it's black, SEND IT BACK!

 

well? di you do any thing with it? Is it still viable?

 

I haven't done anything with it, except I opened it and it smells good. Probably this weekend. (I opened another jar of old yeast and it smelled like Death, but it was discolored so I kind of expected that)

 

I'd consider pitching the slurry as it is and see what happens! It could be fun.

 

Or a sunk expense...

 

I have some from TYB that is 2-3 years old, and this is what I'm going to do for a summer saison. Flame a loop tilt the jar to get in the middle, loop some and put in a 1.030 15 ml sterile wort(pressure cooker),and then do the times 10 to get to 1500 ml. If all the above looks and smells good I'll brew a beer.

 

This thread got me motivated to see if I can revive a Wyeast pack with a manufactured date of Oct 30 2016. I would not go through the effort, but it is that ultra rare 1056.

I had not brewed for 6 months, so I figured buying a bag of grain and ingredients to make an IPA would get me motivated. 2 years later I finally got to brewing that IPA with the other items I purchased, but the pack of yeast has been taking up space in my fridge. Not sure I will actually use it in a batch, but seemed like a good yeast to practice on.

I mixed up 300ml of 1.030 wort and pitched the yeast. The pack was swelled but the inner pouch was intact. The pack did not smell like good fresh yeast, but nothing too objectionable.

 

Baby it along with small starters with nutrients and small steps. Be patient with it and it will probably revive just fine.

All these comments about contamination make little sense. Unless the container was open in the fridge nothing new likely got in so it is as contaminated now as it was back then. If you have some wild yeast or other occupants from when it first went in the fridge they may have had some opportunity to eat and multiply but you should be able to tell whether that is the case by smell or sight in your starters. If it doesn't look or smell as it should then it was contaminated when it went in the fridge.

 

I'm keeping several strains in my fridge this way. 4-5 months old. I just pull them out and make a new starter, stir plate, let it finish, pitch half if I'm brewing and save half in a mason jar to put back in the fridge.

 

So help me understand why you would want to use an old yeast like this? Its not like new yeast is expensive. Does it actually change the flavor because its old? Maybe the cells that thrive in your specific method do better? I mean I can understand unearthing some clay pot form roman times and trying to do it then, since it might be a completely new (old) species that is not around anymore.

So what am I missing here?

 

I'd use it if only just to see what happens Live a little.

 

I couldn't trust a 10 gallon batch to such sketchy yeast. Downside is too punitive, cost wise.
Indeed I recently "flushed the ranch" of pint mason jars holding 8 strains of over-built starters most of which I had been running for a few years and in a couple of strains (1318 and 1056) well over a dozen generations.

They deserved retirement

And I'm starting over. 1318 and 1056 already back on the farm, 2565 and B64 next...

Cheers!

 

To see if it can be done. Also, WY-3333 is a seasonal yeast and not always available (it's not available right now) But the first reason is more important than the second; if I really wanted '3333 yeast I would have used it by now instead of forgetting about it for several years.

I finally made a starter with it tonight. If it takes off and if it smells okay I will use it this weekend in a witbier. (and if it doesn't, I will brew anyway and pitch a packet of T-58)

 

12 hours later and I think I see yeast activity. It's hard to tell because I have it on a stirplate. Tonight I will turn off the stirrer for a while and see if it makes a krausen.

 

When I build up slants I do a shaken first step. With a shaken starter I can tell when Co2 builds and gets released if there is not a krausen.

 

Well, I thought it had bubbles but the stirbar must have been causing those even tho' it was turned down pretty low. I'll give it a few more days before I dump it.

 

I lied. I gave it one more day then I dumped it. And several other old jars of yeast (S-33, why did I even save that?) I will probably order another pack of '3333 when it comes around again and give it another chance. From what I remember, I liked it when I used it.

I don't brew often enough to keep a big library of yeast slurries. Two or 3 at the most, and one of those is reserved for Omega Voss Kveik. (I use that one often enough to keep it alive)

I should look into freezing yeast...