How long would a yeast cake remain viable?

[beardown2489]

Well that took longer that i could have guessed. Took about 30 hours and she is off to the races. It will be neat to see if it attenuates as much, and then of course it will be interesting to taste.

I'm curious to learn your results.

 

[Ian123]

Fermentation is still going strong in all three vnessels, both the new and the old yeast cake both of which are (wyeast 3068.) Are smelling of delicious banana. Which is the way i like em!

 

[JohnSand]

Cool.

 

[Evillegas]

Not wanting to highjack the thread but I have a similar issue and would love some advice..

so I made a 5 gal batch of pale ale a few weeks ago, I harvested the yeast cake from my fermenting bucket, leaving behind most of the trub. I added some un-fermented wort I had stored in the fridge (from the same batch, just the last runnings from the mash tun that I boiled for an hour separately with no hops).

I put this in a sanitized 2 liter plastic soda bottle, and stored it in the fridge. Is this yeast viable? will it still work for another batch of the same pale ale? how much should I use on another 5 gal batch? the whole thing?


Thanks for your input just want to know if I can use this yeast or just get a new vial.

Thanks again.

Ed.

 

[Ian123]

I wish I had more info for you Ed, it will be a few more days before i grab a f.g. and have a chance to taste it. But I will keep you posted. There is a lot of info on here for sure.

 

[Gavin C]

... I added some un-fermented wort I had stored in the fridge ....

Why did you add wort? Is this not a potential source for botulism over time?

When I harvest. Yeast cake goes from FV to sanitized jars and into the fridge. That's it. When I need the yeast, I make a starter ad add the slurry.

I'm afraid I'm not seeing the benefit of adding the wort prior to refrigeration.

 

[Ian123]

I cannot apologize enough for taking this long to get back to you fine folks. Had to take a bit of a hiatus, but I'm now a licensed electrician! So that's good.
Back to the experiment. The beer made with the fresh wyeast 3068 was amazing as ever.
With regards to the older yeast cake: all the calculators i used recommended a crazy amout of slurry based on the age. So i just put 5 gals ontop of the yeast that was there. There was about an inch of beer still ontop from before. I was worried as fermentation took 2 days to start at all, but by day 3 she was going strong.
Conclusions:
The freah yeast was a little better, more banana but thats about it. Both finished at the same alcohol percentage.
So the experiment was a success. In a pinch an older yeast cake will make yummy beer. More testing should probably be done before drawing a concrete conclusion. But good enough for me.
Thanks!