Gelatin's effect on yeast cake

[rossbaker]

I'm looking to pour a fresh wort kit directly onto the us05 yeast cake of the batch I'm currently fermenting. I usually add gelatin when cold crashing on primary. Will the yeast cake still be viable if I do this? Can add gelatin to the keg instead, but I usually prefer not to do this.

 

[Brewno Marz]

I have successfully re-pitched US-05 yeast slurry after cold crash and gelatin. Also successfully re-pitched slurry after CC and gelatin with K-97, Nottingham and W-34/70. So, based on my experience, the yeast cake should still be viable.

 

[mtb]

I've re-pitched a US05 slurry four times, fining with gelatin each time. Hasn't caused me an issue yet, I suspect the yeast continue eating/rooting/making sweet sweet alcohol despite its presence

 

[Coodgee]

I've never been game enough to drop 6 hours of hard work onto a freshly drained fermenter with yeast cake.

 

[rossbaker]

Thanks guys will proceed as normal. You make a good point Coodgee, I haven't done it with one of my all grain batches yet either but I don't have any more yeast and I'm not feeling patient enough to wait until I have a chance to get more. If it goes badly at least it will only be my $ wasted not my time.

 

[captain crumpet]

Nothing is wasted when it comes to learning.

 

[Rocker1986]

There's a difference between repitching slurry and dumping a fresh wort on top of an entire yeast cake, not in terms of what effect gelatine will have on it, but in terms of the pitching rate. Dumping a fresh wort on top of an entire yeast cake is a ******* massive overpitch unless the fresh wort is of considerably larger size and/or OG compared to the previous batch. This could lead to the beer turning out blander than intended due to the lack of multiplying needed by the yeast themselves. For that reason alone I never tip fresh wort onto a whole yeast cake.

I don't use gelatine anymore due to its tendency to make the sediment fluffy/jelly like/easily disturbed (I'm well aware that I may not have been using it properly but I've found isinglass heaps better anyway), and I also build yeast starters every batch and harvest from them too, so I've never re-pitched slurry that's been treated with it. It sounds like it shouldn't be a real problem though.