Bringing yeast back to life???

I have some WhiteLabs California Common yeast that I found buried in my fridge. It was expired in 2011. About four or five days ago I made a starter with 1/2 cup DME and a pint of water. It's in a warm dark spot and didn't do anything noticeable for the first three days or so. Then just since yesterday and last night I am noticing the airlock bubbling a lot but no krausen has formed that I can tell. My question is about what to expect. Will the profile of the yeast still be the same if I can feed it back to life and grow its numbers enough to ferment a batch of beer or will I get adverse effects from using such an old specimen?

 

I would think it is fine. Just keep stepping up the starter a little at a time and see what happens. One thing though: after a few steps its probably no longer cheaper than just buying a new one.

 

Yes, that's a good point. I was really just curious to see if the yeast was still alive after all that time. It's amazing stuff.

 

Just did the same with a batch of 2009 Scottish, tossed it into the bottle, added some 1.035 and turned on the stir plate. Holy god, oxygenated beer tastes like sh*t. I always wondered what it tasted like, I've never had it happen to me yet, I dang sure know now.

Needless to say, it is fine, cold crashed and re-bottled it for a brew later this year.

 

what OG does that yield?

with yeast that old, you want to start small and weak (like under 1.030).

 

I believe 1/2 cup DME to 1 pint of water yields about 1.040 according to Palmer's How to Brew. As far as starting at lower gravity, is that because there are fewer yeast cells alive to begin with when it's that old. I understand sugar concentration can be toxic to yeast at certain solution levels(as low as 5% IIRC). Does that lower gravity just coax the remaining yeast back to life more gently?

 

It was actually a white labs vial that had been in the back of the fridge, I found it and CA Ale, I just boiled up the wort, let it cool in the starter jar with the magnet, once cooled pitched the vial in and turned it on. I'll do the CA ale after I find out what we caught with the wild yeast experiment.

 

I tossed out a vial of Wyeast 001 American Ale yeast this year that was dated in 2011. Thought it was too old, but after reading this thread I guess it wouldn't have hurt to try it out. Living and learning...!

 

you might have been able to coax it back to life, but after a certain point the amount of time and DME required may make it uneconomical.

 

That thought came to mind too, however I always do a 1 pint then 2 pint starter with the WL vials so the cost was the same to me either way for my style of brewing. The only difference I noticed was the 2 day lag and longer ferm time, wholly expected mind you. Truthfully I should have started with a 1/2 pint due to its age, but WTH either it was viable enough to hang or not.