Help with harvested yeast please

[Mouter Senior Member Find all posts View Profile Close Mouter]

I bottled an IPA yesterday after 10 days in primary. There was still occasional airlock action but the gravity had been stable at 1,015 for three days and I’m thirsty. After draining pretty much all the beer I added just over a liter of boiled water cooled to room temperature and gave the carboy a good swirl. Then I carried on priming and capping. I estimate that there was about a 2 l layer of yeast cake before I added the water. I used hop socks during the boil and for dry hopping so there wouldn’t have been any hops in it. I mashed using BIAB.
I couldn’t see a clear distinction in layers after about a hour in the carboy so I decanted about two thirds into a 5 l sterilized jar. After a few hours everything was still in suspension (no settling out) so I left it overnight. Now, about 20 hours after adding water to the yeast cake, there are only two layers - the clear one on top and the creamy one at the bottom. Is it safe to assume that the creamy one is mainly yeast without trub? Can I decant from the 5 l jar into two smaller ones and use one per brew for my next two brews?
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[JIGSAW Senior Member Find all posts View Profile Close JIGSAW]

Im just gonna give a short answer as I dont like to get complicated .... YES

[Mouter Senior Member Find all posts View Profile Close Mouter]

Im just gonna give a short answer as I dont like to get complicated .... YES

Much appreciated. Do I pour off the clear liquid before decanting? And after storing it in the fridge do I just bring it back to room temperature and pitch?

[jannieverjaar Senior Member Find all posts View Profile Close jannieverjaar]

Yes. That will be fine, BUT. Next time. Just mix up that last bit of slurry and bottle it. Mark the caps, store in your fridge and gooi the whole thing into your next brew. It should be fine for long but the longest I've done is 6 months. There are MANY better and more scientific ways of doing it but this way is the simplest with the least chance of infection.

And now I went and elaborated. But anyway there is much more out there. GFGI if you want more info. Washing and glycol storage and such

[JIGSAW Senior Member Find all posts View Profile Close JIGSAW]

Much appreciated. Do I pour off the clear liquid before decanting?

As much as possible yes .... but I always believe its good to have a little sanitary beer on top of your yeast cake you're saving for later.

And after storing it in the fridge do I just bring it back to room temperature and pitch?

I pitch straight from the fridge ... never had a problem ... even Whitelabs suggested to pitch their yeast straight from the fridge

[Mouter Senior Member Find all posts View Profile Close Mouter]

Yes. That will be fine, BUT. Next time. Just mix up that last bit of slurry and bottle it. Mark the caps, store in your fridge and gooi the whole thing into your next brew. It should be fine for long but the longest I've done is 6 months. There are MANY better and more scientific ways of doing it but this way is the simplest with the least chance of infection.

And now I went and elaborated. But anyway there is much more out there. GFGI if you want more info. Washing and glycol storage and such

As much as possible yes .... but I always believe its good to have a little sanitary beer on top of your yeast cake you're saving for later. I pitch straight from the fridge ... never had a problem ... even Whitelabs suggested to pitch their yeast straight from the fridge

Thanks gentlemen

[Toxxyc Senior Member Find all posts View Profile Close Toxxyc]

Just make sure your process is CLEAN. I had a jar of S-189 the other day I wanted to use for a Pils. I saved it in January somewhere I believe. When I opened it, it smelled "funky" and when I let it get to room temp I knew it was totally off. Had to dump it. I think I may have been a bit lax with my sanitizing of the jar.

[Mouter Senior Member Find all posts View Profile Close Mouter]

Thanks, I tend to be quite meticulous with sanitisation but of course anything could happen working in a kitchen. Jannieverjaar’s suggestion of simply bottling the slurry seems to pose the least risk, although that will include trub if there is. Having said that; I didn’t have much success in washing the yeast of my IPA.

[Toxxyc Senior Member Find all posts View Profile Close Toxxyc]

Well I'll be honest here - I bottle the entire slurry. When I'm done bottling, I simply swirl the fermenter to get all the slurry in the bottom nice and loose, and then I just tip over the fermenter into a jar. That's it. Jar is sealed and placed in the fridge. Done. I don't wash, I don't rinse, I don't split. Next brew I just tip the whole jar into the fermenter, sludge and trub and yeast and all.

[groenspookasem Banned Find all posts View Profile Close groenspookasem]

I've done a few methods
- separatory funnel / yeast washing / entire trub dump into a jar after kegging / propagation from trub / top cropping,
the last being my current favorite.
I've top cropped bottom fermenting 34/70 and propagated this successfully, I have however never dumped fresh wort onto an existing yeast cake, it should work, but I have a thing with racking into something clean and sanitized

[Toxxyc Senior Member Find all posts View Profile Close Toxxyc]

I've dumped directly on the yeast cake twice before, and did it for a third time with my currently fermenting Vienna. With the Vienna, it's the first time I'm dumping on top of a lager yeast strain. The cake came from my Pilsner I made a few weeks ago, and I don't know why (maybe because it's a lager yeast), the yeast cake was MASSIVE. I usually have between 1 and 2 litres of yeast cake in the bottom of my fermenter. It's usually closer to 1l when it's nice and compacted following a week on gelatin at near freezing.

This time though, I added gelatin and left it at 1°C for more than a week. The yeast/sediment cake was so thick, it extended past the tap opening and I actually pulled half a bottle of plain yeast when bottling before the actual beer started flowing. So when I was done, I figured I can't just dump the cube on the thick yeast cake, so I drastically thinned it out. I swirled and decanted a 750ml jar full which I stored, and then dumped out some more as well to give some breathing room at the bottom of the fermenter. I then proceeded to dump the cube of Vienna onto the remainder of the cake and I had a nice and active fermentation 6 hours later.

I'll see how the sediment looks when the Vienna is done, but I can already see it's not THAT thick. I don't know why it was that thick either. Perhaps because of the larger grain bill, I dunno.

[JIGSAW Senior Member Find all posts View Profile Close JIGSAW]

...and you people all thought I was mad when I said this is what i do and I re-use my yeast up to 15x over



PS: CraigTube is sitting on close to 2yrs of using the same slurry of yeast and that guy does on average 4x brews per month

[groenspookasem Banned Find all posts View Profile Close groenspookasem]

Sounds a bit like an overpitch, do remember (simplified) that yeast propagates aerobically and ferments anaerobically, some cells die others are cannibalized but billions of yeast cells do flocculate and fall out of suspension on cold crash/fining with some proteins and hop particles added. If you keep on reusing your trub/yeast cake, it will grow. Generally fresh yeast off a recent fermentation will get going a lot faster, the longer it's dormant the slower the startup process. I wondered on the wort oxygenation issue in cubes and how yeast will perform in an oxygen poor environment from the start. Simple, pitch enough and it will ferment, the bit of oxygen you introduce when racking from cooled wort into your fermentor only assists the yeast a little for initial propagation and you should be pitching enough in anyway

Another reason I like kveik, you can use a teaspoon of slurry for your next batch and it will be actively fermenting in 3 hours

[groenspookasem Banned Find all posts View Profile Close groenspookasem]

...and you people all thought I was mad when I said this is what i do and I re-use my yeast up to 15x over



PS: CraigTube is sitting on close to 2yrs of using the same slurry of yeast and that guy does on average 4x brews per month

I still have the original strain of Voss, Stranda, Skare, Oslo and Simonaitis - I've been reusing them since initial stirplate propagation. Haven't bough a packet of yeast in a very long time

[Toxxyc Senior Member Find all posts View Profile Close Toxxyc]

...and you people all thought I was mad when I said this is what i do and I re-use my yeast up to 15x over



PS: CraigTube is sitting on close to 2yrs of using the same slurry of yeast and that guy does on average 4x brews per month

This, yes.

I have to add that if you make regular beers all the time, this will work. However, there's apparently a microbiological reason for not reusing yeast over and over in high-alcohol batches for too many brews in a row. Apparently the ethanol eats away at the cell walls of the yeast cells, reducing their capacity to replicate and do their work, which causes off flavours in lighter brews. As I said, it's apparently not an issue for beers, but when you're making Belgian Quads all the time, it's not a bad idea to get some fresh yeast once in a while. I know with consistently making 14% ABV and up meads, the flavour changes based on the age of the yeast. Again, not an issue with beers, I believe.