We have some Wyeast Czech Pils yeast (2278) that was harvested last summer, mid July.
I decanted the liquid off the yeast cake. It did not taste good, with a very slight but noticeable off flavor. The yeast itself has a clean, and pleasant aroma.
Do we dare give this yeast a try? Or should we just dump it? It has been sitting in cold storage (38 F) all this time.
I am tempted to try it, but do not want to waste a brew day and 10 gallons of beer.
What would you do?
I wouldn’t go by the flavor of the beer on top, obviously it’s going to be oxidized and yucky. If the slurry is still a lightish tan and not dark as peanut butter I have had good luck.
You can of course make a starter and see if it’s active.
Yes, that is what I’m thinking. A starter will be made today, and see how it goes. I hate to throw away good yeast!
The few times I have had slurry not viable it was dark colored. Ditto with sourdopugh starter. The liquid can be dark and nasty though.
I’ve pushed it by using yeast like that a couple times and I’ve regretted it.
Interesting how there’s a hesitation to use unopened package of dry yeast nearing the expiration yet a willingness to use a six month old harvested slurry. Seems contradictory to me but to each his own. [emoji2369]
Make a starter with it and adjust your beer that you want to make by 2 extra gallons. Take the 2 extra gallons and add the appropriate amount of yeast and see how it turns out. It will give you a definitive answer to the question and it isn’t going to cost much at all. If it’s good then use on your next batch.
There is no hesitation at all to use the Diamond, as it nears the end of it’s shelf life. But there is hesitation to use this, unless it proves to be Ok in the starter.
I have used 5 month old harvested yeast before, without any problem. I like to brew right away with any yeast that is saved from a previous beer.
Update:
This Czech Pils Yeast is not going to work, dang it! Simply not active enough. Did all we could to bring it to life. It looks good, and has a nice clean aroma. But after 24 hours of feeding with sterile wort, very little activity taking place.
So we are off to the Diamond.
Don’t get me wrong, I’d probably still go to my backup plan if I was in your situation, but 2278 is a very quiet fermenter in my experience. There have been a couple of occasions where I was concerned that I got a dead pack of this yeast, but when I tested the gravity it was right where I expected and the beer tasted great. Again, I don’t know if I’d roll the dice on an old slurry that I wasn’t sure of, but I’d say there’s at least a 75% chance that this pitch would make good beer.
I was tempted! The aroma was so clean and fresh. It looked very good, with a 2 inch high Krausen. But the airlock activity was so slow. So I chose to dump it, rather than take a chance. It was fed three times with sterile wort. Thought for sure it would take off. But it never was active enough to make me confident in the results of fermenting 10 gallons.
So I rolled the dice, taking a chance with Diamond…based on the advice on this forum.