# Re-using Trub At Bottom Of Fermenter?



## RichLum (20/11/04)

Hi all,

I've read about re-using the yeast at the bottom of the fermenter but am not sure exactly what this means....

After bottling the beer do you just leave what's in the bottom there and then dump your next kit on top, stir it up and that's it?

Do you need to add more yeast?

Obviously this would mean that you can't just dump hot water straight into the fermenter to mix up your kit either or you'll kill the yeast yeah?

Currently I have a Morgans Dark Ale that I added liquid choc malt and also some steeped choc grain and goldings hops and Safale yeast in there and it should be ready to bottle next weekend.

I was thinking of just pitching an amber ale on top of the trub to see what that tastes like.
Or would it be better to just clean out the fermenter and start fresh since the types of beer are different?

thanks,
Rich


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## MCWB (20/11/04)

You've got it, just dump your next (cooled) wort on top of the old yeast cake and you're in business! I often do this, first brew in primary for a week, make second wort, rack first brew to secondary then rack second wort onto the yeast cake. I usually brew a stronger and/or darker beer second.

The other option is to harvest about a cup of the slurry, rather than using the whole thing again.


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## RichLum (20/11/04)

Thanks MCWB.

Why do you rack the second wort onto the yeast cake?
Wouldn't dumping it in and mixing it all up and oxygenating it be better for the yeast to start fermenting?

And so no need to add more yeast with the second word right?


thanks,
Rich


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## MCWB (20/11/04)

Actually I just syphon the cooled wort straight from my boiler, but only because I haven't been bothered putting a tap in it yet! I make sure it splashes around a bit too, so it's nicely aerated.

Correct, you don't need any more yeast. Compare how much is in your yeast pack to how much is on the bottom of your fermenter...


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## pint of lager (20/11/04)

> "Wouldn't dumping it in and mixing it all up and oxygenating it be better for the yeast to start fermenting?"



Yes this is correct, just dump it in amd mix it all up, you want lots of oxygen at the start.

A better method is to harvest about half a cup of slurry from the bottom of the fermenter and add this to a fresh brew in a fresh fermenter. This way, you are using a nice clean fermenter and not adding truckloads of yeast. Pitching too much yeast can be a problem.

Also, with pitching large quantities of fresh yeast, watch your fermentation temperautures as they can take off.

There is no need to add extra packet yeast to the second brew if you have al;ready pitched some fresh slurry in it.

If you want, check out the White Labs webpage, http://www.whitelabs.com for details on yeast care and yeast washing.

Watch out for escaping yeast, you may need to fit a blow off tube to your primary fermenter.


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## Jovial_Monk (20/11/04)

Slurry (the yeast from the bottom of the fermenter) has loads of yeast cells, no need to aerate the wort you pour onto it.

Probably the best way to do it is to use more than one fermenter, and pitch the yeast cake into progressively stronger and darker beer.

Make up wort one, pitch a liquid (or other, but the cost of liquid yeast makes this repitching almost mandatory) yeast and ferment out. Just before racking beer 1 make up wort 2 in a new clean fermenter. Rack beer 1 out, leaving the tiniest bit of beer behind. Close tap, fit lid, swirl fermenter to 'liquify' the yeast cake, then run this through the tap into wort 2. Fit lid and airlock to fermenter 2 and watch the airlock start bubbling immediately 

Clean fermenter 1 and have ready as fermenter '3', repeat the process with beer 2 and fermenter/wort 3 but use only half the yeast cake which will now be bigger than it was originally (in fact, you can pitch the cake from fermenter 2 into two fermenters to get 4 beers out of one liquid yeast.

Big breweries repitch yeast, usually bottom cropped, 8-10 times then the yeast is used only for making Vegemite. Home brewers should only repitch twice. It calls for a bit of planning, what beers are suitable for pitching with whatever yeast and working out in what order to brew and pitch the beers.

Jovial Monk


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## big d (20/11/04)

and thinking of cost its a great way to maximize liquid yeast usage.

cheers
big d


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## Gulf Brewery (20/11/04)

Jovial_Monk said:


> Slurry (the yeast from the bottom of the fermenter) has loads of yeast cells, no need to aerate the wort you pour onto it.
> 
> <snipped>
> 
> Jovial Monk


 Hi

Yes, the slurry has loads of yeast cells, but oxygen is important to the health of the yeast cell and you have to aerate and to allow the yeast to multiply. If you don't, the only yeast cells that can convert your wort to beer are the viable ones of the slurry. 

There are loads of professional brewing references that tell you that oxygen is required.

Cheers
Pedro


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## RichLum (21/11/04)

Thanks for all the advice.
I'll probably be doing this next weekend so I'll see how it all goes

Rich


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## sluggerdog (23/5/05)

Am thinking of doing this for the first time, if you want to store the yeast/slurry can you just bottle the collections and store it in the fridge until you need it?


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## Ross (23/5/05)

sluggerdog said:


> Am thinking of doing this for the first time, if you want to store the yeast/slurry can you just bottle the collections and store it in the fridge until you need it?
> [post="60299"][/post]​




Slugger,

Yes, just store in bottles in the fridge & warm the day before to brew temp...


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## warrenlw63 (23/5/05)

Works fine,  

Just make sure you handle your yeast as cleanly as you can. Don't store it in the fridge for too long either.

I use similar methods. My beers are fermented in glass carboys. If I wish to re-use the yeast after racking what I do is flame the mouth of the carboy with a gas match after wiping it first with some metho or Iso-propyl swabs. Then I just swirl the carboy and pour the contents into a 2 litre mason jar.

These are good as they have a wide mouth and are pretty easy to sanitize.

On brew day all I do is take the yeast out of the fridge a few hours before pitching the new batch. I pour the old beer (carefully) off the top, then add about 500ml of the new wort after cooling.

I let my new brew sit in the kettle for about 30mins after cooling and whirlpooling to let the trub settle. Then I get my yeast and fresh wort and shake it around to mix the yeast into the wort (carefully). This is then just pitched to the fermenters. Truth be told if your yeast is pretty fresh you could probably to the same thing with some sterile water instead of wort.

Hope this helps -

Warren


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## nonicman (23/5/05)

Slugger if you intend to store the slurry under wort for more than a week or two, beware that it will continue to ferment even in the fridge. Opening a longneck of 2 month old slurry is an experience I wont be repeating, slurry all over the kitchen including the ceiling, floor, sink, bench, walls and myself, Mrs Nonic was not impressed uncovering stinky slurry in the nooks and crannies of the kitchen for the next week or so.

Edit: I was surprised at the pressure in that bottle, if it wasn't an old Pick Axe Coopers bottle I'm sure I would opened the fridge oneday, knocked it by accident and copped a face full of glass.

Forgot to add, I don't store slurry under wort in capped bottles anymore. Either store under very well boiled water as per this thread Yeast Farming by Chiller or as I have at the moment reuse the slurry from one brew to the next.


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## Jim - Perth (23/5/05)

I suggest that you store yeast in the fridge in plastic bottles just in case + loosen cap from time to time to release pressure!


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## TidalPete (23/5/05)

nonicman said:


> Slugger if you intend to store the slurry under wort for more than a week or two, beware that it will continue to ferment even in the fridge. Opening a longneck of 2 month old slurry is an experience I wont be repeating



Nonicman,
Was the wort fermented right out? :blink: Was the fridge turned off?   Perhaps it was just one of those things? I used to save the slurry from my worts in a sterilised vegemite jar & re-use 8 or 9 times before culturing another Coopers Pale Ale yeast for re-use. Never had any problems. Stopped doing this when I realised that splitting up & saving the original liquid yeast was a more hygenic option.


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## nonicman (23/5/05)

Tidalpete said:


> Nonicman,
> Was the wort fermented right out? :blink: Was the fridge turned off?  Perhaps it was just one of those things? I used to save the slurry from my worts in a sterilised vegemite jar & re-use 8 or 9 times before culturing another Coopers Pale Ale yeast for re-use. Never had any problems. Stopped doing this when I realised that splitting up & saving the original liquid yeast was a more hygenic option.
> [post="60339"][/post]​



Pure primary wort slurry, was it fully fermented out? I thought so at the time I reasoned that the fridge would stop any further fermentation anyway. This was my first attempt at storing yeasties. That 750 of slurry didn't look too apealling against the new yeast vial I had so didn't get used for the next brew, would have been fine otherwise. Soon after that I was washing the slurry as per Chiller's post and other articles then stored under sterilised water in capped stubbies. It was when I was looking through the library of yeast stubbies after a few months of gentle proding (something about an invasion and take over of the fridge, couldn't we just buy what we need each day?). Thats when I remembered the Burtons Ale yeast slurry. I guess the slurry could have been in the fridge two months it could have been more like 4. 

Sorry to hijack the thread, wouldn't want anyone to get injured whilst in the pursuit of our great obsession. Even it if I look like an idiot  :beer: 

Shameless reposting of Yeast Farming 

Cheers,

Jason

edit: spelling


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## Trough Lolly (23/5/05)

There's nothing wrong in adding personal experience to the forum Jason! The first time I tried to re-use yeast slurry, I put 2.8L of it in a 3L coke bottle and thoughtfully put an airlock in a rubber stopper on top...I eventually found the bung elsewhere in the laundry the following morning - thank god it was a tiled area, and I managed to wipe down the brand new Maytag front loader before SWMBO saw it  
Cheers,
TL


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## TidalPete (24/5/05)

nonicman said:


> Thats when I remembered the Burtons Ale yeast slurry.



Nonicman,
Musing on your misfortune overnight I got to thinking that the yeast in question may have been a lager, or similar low fermenting yeast that had not quite fermented out fully. From your previous post I see that it was an ale yeast. I had previously assumed that an ale yeast would be dormant at such low temps in the fridge. Clearly, this line of thinking is incorrect.  I'm glad I don't store slurry anymore.  Chiller's post on yeast farming is excellent & I am storing it away for future reference.


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## Wortgames (24/5/05)

In my experience any yeast will continue to ferment, even at low temps and under 'fermented' wort.

I think one of the things that is happening is the yeast is slowly mutating to digest the tougher sugars and dextrins in the wort, and I'm sure it will be autolyzing to a certain extent too albeit slowly.

I have stored slurry for several months in Grolsche bottles (cracking the seal once a week or so to relieve pressure). I would be happy to use yeast stored this way for about 3 months, but after this I would say that it has probably mutated enough to affect flavour and attenuation.

This is just based on observation and guesswork though, so I'd be interested to hear if anyone agrees / disagrees.


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## RobW (24/5/05)

Wortgames said:


> In my experience any yeast will continue to ferment, even at low temps and under 'fermented' wort.
> 
> I think one of the things that is happening is the yeast is slowly mutating to digest the tougher sugars and dextrins in the wort, and I'm sure it will be autolyzing to a certain extent too albeit slowly.
> 
> ...



Agreed. And that's why longer term storage is better done on plates/slants or under sterile water.


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## Ross (24/5/05)

Wortgames said:


> In my experience any yeast will continue to ferment, even at low temps and under 'fermented' wort.
> 
> I think one of the things that is happening is the yeast is slowly mutating to digest the tougher sugars and dextrins in the wort, and I'm sure it will be autolyzing to a certain extent too albeit slowly.
> 
> ...



Then why do people recover yeast from commercial bottles - not much point if they are mutated?? Just a question, as I'm pretty new to yeast harvesting...


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## Trough Lolly (24/5/05)

Wortgames said:


> ...I have stored slurry for several months in Grolsche bottles (cracking the seal once a week or so to relieve pressure). I would be happy to use yeast stored this way for about 3 months, but after this I would say that it has probably mutated enough to affect flavour and attenuation.



I've got 12 month old stubbies of 1056, 1028, and lager yeast strains in the fridge and I use them for all brews. I must confess that if I didn't have a problem with finance, I'd go to slants and plating yeast etc, but the yeast under wort method will have to do for now. I have had no apparent issues autolysis wise but I must confess as the stubbies get older, I need to use more than one to build up a decent sized starter.

I have a Skunk Fart clone in primary now and its still bubbling along, albeit slowly, at 17C at day 9 of primary. I used 18 month old 1056 yeast and a sachet of S-04 tossed in for good measure!

TL


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## Wortgames (24/5/05)

I don't think it's so much a case of having 'problems', I reckon you could successfully use yeast thats been stored under beer for years as long as it is still clean and there are some viable cells. I just wonder how much the yeast profile would evolve in that time, into some kind of Saccharomyces Schwarzeneggensis - presumably only the strongest cells would survive by metabolizing the tougher stuff in the wort, resulting in a different beer.


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## jgriffin (24/5/05)

nonicman said:


> Slugger if you intend to store the slurry under wort for more than a week or two, beware that it will continue to ferment even in the fridge. Opening a longneck of 2 month old slurry is an experience I wont be repeating, slurry all over the kitchen including the ceiling, floor, sink, bench, walls and myself, Mrs Nonic was not impressed uncovering stinky slurry in the nooks and crannies of the kitchen for the next week or so.
> 
> Edit: I was surprised at the pressure in that bottle, if it wasn't an old Pick Axe Coopers bottle I'm sure I would opened the fridge oneday, knocked it by accident and copped a face full of glass.



Sounds like a gusher infection to me. I've had the same in stored yeast, and after testing the remnants, they were all infected.


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## nonicman (24/5/05)

jgriffin said:


> Sounds like a gusher infection to me. I've had the same in stored yeast, and after testing the remnants, they were all infected.
> [post="60534"][/post]​



That would explain a lot.

edit:typo


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## dickTed (24/5/05)

Thought I'd jump in on this thread, since it's the same subject.

Suppose I washed some yeast trub to use as yeast nutrient.

Wouldn't I just be able to take it from the fridge, and chuck it into the boil pot at about 10-15 mins to go?


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## sosman (24/5/05)

dickTed said:


> Thought I'd jump in on this thread, since it's the same subject.
> 
> Suppose I washed some yeast trub to use as yeast nutrient.
> 
> ...


Probably no reason why not, I have used bakers yeast like that before. The trub is not pure yeast so it depends on how well you wash it and what else it might contain.


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## sluggerdog (1/6/05)

Ross said:


> sluggerdog said:
> 
> 
> > Am thinking of doing this for the first time, if you want to store the yeast/slurry can you just bottle the collections and store it in the fridge until you need it?
> ...




Ok I have done this and am ready to use it again, my only question is how long can I keep it in the fridge like this? was planing only for a few days but work came up so it would be about 2 weeks from collection to re-using.

Is this too long?


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## Jovial_Monk (1/6/05)

you need to store it quite cool, 4C, and one week seems to be specified as the maximum time yeast can be stored like this. In practise, up to one month is OK

Jovial Monk


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## sluggerdog (1/6/05)

Thanks JM, it has been in the fridge since I collected it. So maybe I will buy some more yeast for backup incase it works but it should be ok as it is only 2 weeks..


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## Gulf Brewery (1/6/05)

sluggerdog said:


> Ok I have done this and am ready to use it again, my only question is how long can I keep it in the fridge like this? was planing only for a few days but work came up so it would be about 2 weeks from collection to re-using.
> 
> Is this too long?
> [



Sluggerdog

Chris White of Whitelabs suggests that 2 weeks "is the magic number". Have a look at this article. 

Cheers
Pedro


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## sluggerdog (1/6/05)

thanks Pedro!

while we are at it, how long can you store your starter bottles in the fridge? I have had mine in the for about 5 months without a drama, just wondering is there a used by date on these?


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## Gulf Brewery (1/6/05)

Sluggerdog

Are you talking about yeast stored under beer in the fridge? It's not something I do, though people quote the 6 to 12 month mark. 

I think this is OK for a ale yeast but for a lager yeast that is still active at low (fridge) temperatures, I would worry that it autolysis may occur - _this is speculation, not fact._

Cheers
Pedro


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## sluggerdog (1/6/05)

Pedro I am talking about starters I made up from a smack pack which I then store in the fridge until ready and then bring out and continue with...


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## Gulf Brewery (1/6/05)

Sluugerdog

In that case, it is storing them under beer.

If you are going to do that, I think a better way is to make the starter a week or 2 in advance of when you need it, pour of the liquid and step the slurry up, then pitch.

Cheers
Pedro


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## sluggerdog (1/6/05)

Gulf Brewery said:


> Sluugerdog
> 
> In that case, it is storing them under beer.
> 
> ...



So I don't want that few hundred mls of wort/beer that I have sitting in my drink bottles in the fridge? I only want the yeast/slurry?

So next time, tip out the wort in the bottle, marke some fresh wort and add to a larger bottle with the slurry and wait for some action then pitch?

Thanks Mate..


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## Gulf Brewery (1/6/05)

Sluggerdog

The liquid portion will have very little yeast. What you ideally want is the yeast from the top of the slurry. If you do some in a clear bottle, you can see the layers of the yeast and trub. Pour off most of the liquid, swirl the top layer of yeast (leave the crud at the bottom behind) and pour that into your starter.

Once you see action on the starter, it will take off rapidly and it can be pitched fairly quickly.

Cheer
Pedro


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## sluggerdog (1/6/05)

so the crud at the bottle is the stuff that I have in the past, shaken the shit out of the bottle to get it up and loose so I can pour into the bigger bottle with the fresh wort.

I don't need/want the crud that sticks anyway?


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## Gulf Brewery (1/6/05)

Correct - it is only partly yeast which is not healthy anyhow


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## sluggerdog (1/6/05)

Thanks for clearing that up. Easy As! 

hehe

Cheers
SD


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## crusher (11/6/05)

Hey Fellas'
Back on re using trub from fermenter,is it possible to get a brew going from pitching on top of trub left at bottom of secondary. Reason I'm asking is I was wanting to put on a brew tomorrow & completely forgot about getting a starter going beforehand. I have a APA coming out of secondary & if possible will dump on top. Thanks for any help.
Crusher.


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## Steve (11/6/05)

Crusher
Yes...ive heard of lots of people doing it with no worries. Obviously as long as your new brew is similar to the APA that is done. 
Cheers
Steve


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## homebrewworld.com (11/6/05)

Oh yeah, i works like a train !
Dump onto the previous yeast cake, and whoooshka!
I agree with AlienBoy, i wouldn't do it straight onto the cake more than once or stretch it to twice.
go for it !
cheers


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## crusher (12/6/05)

Fellas,thanks for response. I have dumped on top of primary before no problems, but what I was wondering was can you do it on trub left at bottom of secondary
Crusher.


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## nonicman (12/6/05)

Hi Crusher, 
I've not pitched onto the yeast that has dropped out in secondary. I would assume that this yeast are the strugglers in the yeast population (as I'm guessing you are thinking the same), but they are alive (you could test them in a starter), and hopefully willing to work. If you have no other option, they could get you started untill you can get some fresh yeast or a packet of dried yeast. 

I would go for it but would be worried that the yeast will not fully ferment the wort and hence I'd get some fresh yeast ASAP, however it may work fine and would be better than not brewing. 

Hopefully POL or someone knowledgible can set you straight.

edit: sp

Edit: from the following posts it appears my above concerns are not fully justified.


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## Trent (12/6/05)

Crusher
I have pitched onto a primary cake before, and it ended up tasting awful. I am pretty sure, and anyone may feel free to correct me, that the reason we rack to secondary is to get the beer off the primary cake, which will contain alot of dead/dying cells, which COULD lead to autolysis, which is what appeared (I assume) to happen in my experience, cause it was in summer and I didnt have a ferment fridge then. The yeast that makes it through th secondary is still in suspension, and eating away the sugar, and should be more than healthy enough to kickstart again in your new brew. I am about to do this with a russian imperial stout, and Darren pointed out to me that if the OG of your original beer was more than 1055, they yeast may not be in the best shape, and it could benifit from dropping in a few litres of about 1030 wort for a few days to bring em back to life, the drain that off and pitch your new brew. I know that Palmer also recommends dropping big beers onto a secondary yeast cake, not a primary cake. So, I reckon the only way to go is onto a secondary cake (IMO), and I dont think that you will need to add more yeast, just make sure ya aerate well.
All the best
Trent


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## sosman (12/6/05)

crusher said:


> Fellas,thanks for response. I have dumped on top of primary before no problems, but what I was wondering was can you do it on trub left at bottom of secondary
> [post="63216"][/post]​


Crusher, I haven't done this personally but from all accounts that works just fine. Remember that yeast that made it to secondary is likely to be less flocculant than the stuff glued to the bottom of the primary. Recycling this multiple times might lead to flocculation problems among other things. 

On the plus side, the yeast should be fairly clean and relative free from hop residue and break material.


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## nonicman (12/6/05)

> 8.1.1 Yeast Factors
> 
> The first step to achieving a good fermentation is to pitch enough yeast. The yeast can be grown via yeast starters or it can be harvested from previous fermentations. When yeast is harvested from a previous fermentation, it should be taken from the primary yeast cake and preferably from the upper layer of the cake or from the secondary. This yeast will have the optimum characteristics for re-pitching. In either case, you should target pitching at least 1/3 cup (75 ml) of yeast slurry to a typical 5 gallon batch of ale or 2/3 cup of slurry for lagers. For stronger beers, OG > 1.050, more yeast should be pitched to ensure optimum fermentations. For very strong beers like doppelbocks and barleywines, at least 1 cup of slurry should be pitched.



http://www.howtobrew.com/section1/chapter8-1-1.html

Well there you go, secondary yeast may be ok after all. 
Trent, I've not had any problems with fresh primary slurry, however, generally use a fresh fermenter and don't add all the slurry (including trying not to use the thick bottom layer left in the primary fermenter), and have a converted freezer to regulate the high temps produced by using a large yeast population.


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## Bilph (12/6/05)

I've pitched straight onto the secondary. It works fine, but there is a lot of yeast in yeast cakes, even in the secondary.
You only need about half a cup of slurry.
I would actually suggest just rinsing the secondary with cooled boiled water.
Wash it through into a sterilsed container and let the heavier stuff settle for a bit (even 10mins or so) and pitch the yeast suspended in the liquid into your next brew.


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## Trent (13/6/05)

Nonic
The time I pitched onto the primary cake, I just poured my next brew on top of the whole cake, as per instructions from a HBS guy. As we all know, those instructions arent always accurate, so maybe had I have done it the way you did it, I may not have had the problem I did. After reading Chillers yeast farming article (excellent article BTW), and reading Bliph's post, I may just even try it for my RIS, cause it sounds pretty sensible.
All the best
Trent


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## Weizguy (13/6/05)

I agree with Trent re the possibility of autolysis. It may take a bit longer to happen in Winter, but still can occur. However, it should not occur if you rack and bottle on the regular timetable.

Do not leave the beer too long on the yeast cake. There are already big numbers of fungi in the there (yeast, that is), and some are probably turning to the dark side already. Yep they are thinking about cannibalism (teliologically speaking).

The batch should take off like a rocket and ferment quickly, so monitor the gravity and rack at the relevant time. This should leave most of the old burnt-out cells behind.

It just goes to show how well a ferment can occur when pitched with appropriate yeast density.
Beers

Seth out


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## vlbaby (14/6/05)

I have to wonder how critical the timing is in regard to autolysis. I would imagine that seeing coopers and many others bottle condition their beers, then the yeast must last a long time before they die and rupture bad flavours into the beer.
But I could be wrong, its happened before.  


vlbaby.


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## Weizguy (14/6/05)

vlbaby said:


> I have to wonder how critical the timing is in regard to autolysis. I would imagine that seeing coopers and many others bottle condition their beers, then the yeast must last a long time before they die and rupture bad flavours into the beer.
> But I could be wrong, its happened before.
> 
> 
> ...



vl,

I think that the yeast numbers are the problem. As U might expect, the bottle-conditioned beers have only a thin layer of yeast and a small amount of yeast.

However, in the bottom of the fermentor, there exist a large population of yeast cells and the pressure (both physical and envrironmental) on each cell is heavily increased.
They have to cope in a milieu of yeast waste products and trying to exist close to expired cells etc. A vague analogy to the New York or Hong Kong environments could be drawn.

Seth


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