Reusing yeast cake

[Reviled]

Hey guys, I re-use yeast cakes all the time, but generally what I do, is keg the batch, then dump onto the yeast cake ASAP...

What I was wondering, if I say, kegged the CAP i have, would I still be able to leave the fermenter with the yeast cake for a week or so before I pitch onto it? Or will I be risking it by doing this??

My thoughts are maybe the extra oxygen or something may stuff with it somehow? But im not sure...

[Andrew]

Man that must have been some mutant yeast even if you did over-pitch!!! Yeast on Nitrous....

[Stu McKinlay]

it was a "yeast cake" rather than "pitch"...

 

without looking back on records, I can't remember what the previous batch was but I remember it was three years ago... Think it was S05, 2nd gen, probably that S05 batch that everyone complained about ;-)  A dangerous mix of acetaldehyde and ethyl acetate (I'd like to say "apples and pears" but that would be beyond a euphemism).

 

It was at ambient overnight temp, which would be 20c tops in Wellington.

[Mike Neilson]

Temp control!!!!!!!!!!! Homebrewing 101 that one Stu hahaha.

[FatD]

Just did a 20L batch and it's finishing tomorrow, can i pitch a 40 litre wort on the same yeast cake, or would i have to add another packet of dry yeast as well? Assuming i have 400ml of slurry..

[jt]

www.mrmalty.com/calc/calc.html will tell you how much to use, excellent tool

[FatD]

yer i went there, said about 260-300ml. just wondering what others experiences are.. weird how it could do double size batch.. cheers,

[jt]

I've used it a lot and I've found it accurate - my only problem is that I'm not so accurate with my own measurement of slurry ie the 83ml I require is more likely to end up being 85 or 90ml

[JackoNZ]

Would you guys reuse s-05 yeast that has been fermented at 15c? It was 1 packet in 10L of 1.055. I think it should be ok but not sure if at that temp it's been too stressed?

[MrC]

Would you guys reuse s-05 yeast that has been fermented at 15c?

Yes, I would.   I don't re-use yeast that has been fermented at the high end of the fermentation range but I happily re-use yeast  that has been fermented in the mid to low range and has kept fairly constant.  

 

As a general rule I look for yeast derived off flavours in the beer and avoid re-using the yeast if I find any.

 

[JackoNZ]

Cheers Mr C, I'll harvest some of that yeast shortly and check for off flavours before reusing.

[jt]

I'll add a yes to that too. There's nothing wrong with 15c, it's in it's range and should be good!