[Poobah58]

Ooops, I misread the post. I did not have a slurry. I had an package of Wyeast yeast.... Never mind! 

[el_capitan]

Well, call me a fool but I actually went ahead and fermented a batch with this two-year-old slurry.   

I doubled my batch size and split it into two fermenters.  One bucket got a fresh vial of WLP029.  I didn't make a starter, because the yeast was super fresh and it was only a 3-gallon batch of kolsch. 

The other bucket got a big stirred starter of the 2-year old WY2565 slurry.  I actually ran that slurry through two starters, just to be sure that it wasn't bacterially contaminated. 

The 2565 version has been in the keg for a few weeks now.  I just hit it with gelatin last weekend, and now it has dropped brilliantly clear.  I have to say that it's really an excellent kolsch.  This is only the 4th batch of kolsch that I've brewed, but it's incredibly good.  The spritzy/fruity/winey yeast character is coming through really well.  The WLP029 version is kegged but still in the pipeline, so I can't do a direct comparison yet. 

Maybe I just lucked out with this batch, but I wanted to share my success and let you all know that it is in fact possible to brew great beer with 2-year-old yeast.  Advisable?  Maybe not.  But for me it was worth the small investment of grain and time, and it paid off!  Cheers. 

[ynotbrusum]

Congrats!  Glad to hear it.  You just never know what you are gonna get with that "box of chocolates".  Sometimes it is just what you wanted!,

[dcb]

Well, call me a fool but I actually went ahead and fermented a batch with this two-year-old slurry.   

I'd rather call you curious.  Reading through this thread I was thinking if this were my yeast I'd make another batch just to see how the older yeast did.  Even anecdotal findings are interesting-- thanks!

[coolman26]

I have made beer several times with yeast that was 1.5 to 2 years old.  I've never had it stall or act funny.  They were in the vial or smack though.  Glad you split the batch so you could get the results.  Makes me want to make a batch of Kolsch now.

[el_capitan]

Man, that's a good kolsch!  The recipe I'm going with is one published in BYO a couple years ago - "Goose Island Summertime Kolsch".  It has a couple pounds of wheat malt, which I like. 

[a10t2]

Now that we know you have a viable culture, I'd love to hear how it does after repitching a couple times.

[el_capitan]

Now that we know you have a viable culture, I'd love to hear how it does after repitching a couple times.

Sure - what would you expect?  This was a generation 2 slurry, but then I ran it through a 2-step starter before pitching.  So does that make it technically a 5th generation now? 

I'm going to compare this to the WLP029 and then make the call on which one to keep.  My yeast bank is kind of packed right now. 

[klickitat jim]

I count a generation once it has fully fermented a batch of beer and flocced out. I don't count starters. Some of my early brews were actually still first generation... ;-)