Pitching Onto A Yeast Cake More Than Once

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T.D.

Hop Whore
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So, everybody says, "don't leave a beer sitting in the primary fermenter for longer than 2-3 weeks" because you may subject yourself to autolysis.

For my last lager, I couldn't bring myself to throw out all that nice yeast sludge (Saflager 34/70), only to brew another lager and have to pitch 2 new sachets on it. Surely the yeast cake left from the previous lager would be like a "super starter". So I pitched my latest lager on the yeast cake and it went like a dream, tastes great out of the fermenter etc etc. I now have a bock that I want to ferment. Its obviously high gravity, so a good dose of yeast is preferred. At this stage I am going to pitch the bock on the yeast cake, which will make it the third brew in a row on that yeast.

Am I subjecting myself to autolysis by doing this? Is what I am doing sort of like leaving a beer sitting in primary for 6 weeks (3 brews X 2 weeks each)?

How many times can you safely pitch a new brew on the yeast cake of an old one?

Cheers :beer:
 
T.D.

I've gotten away doing it twice. Subsequent beers were good. I suspect if your sanitation's sound you could probably get away with it 3-4 times. :unsure:

Word of warning if you're pitching a lager on a yeast cake though (or even an ale for that matter). Make sure your pitching temp of your wort is on the low side (no more than about 12 degrees for a lager) or you may get a runaway ferment and a resultant fruity lager.

Warren -
 
Thanks Warren. So you wouldn't be too worried about autolysis?

I have been chilling each lot of lager wort in the fridge first and I'll be doing the same with this cube of bock too. Gotta love no chiller! :D :ph34r:
 
T.D.

I've never noticed any myself. That said there's no guarantees in a perfect world. I guess you'll just have to find out. ;)

All that said in 9 years of making beer I can only ever recollect one autolised beer and that was a K&K job I left in the primary for about 5 weeks. :)

Autolysis tends to be one of those HB Boogie Men that people tell us about to stop us wandering around at night. :lol:

Warren -
 
:lol: yeah, I have never experienced it myself, but I get the impression that it may be a tad over-stated, like a lot of things in brewing! :rolleyes:
 
Yeast autolysis is a very real problem, and is linked to yeast handling and storage. If your yeast is healthy you will be unlikely to encounter this problem. Here is a good link with info on causes ect.
Yeast Autolysis

Cheers
Andrew
 
nothing wrong per se in pitching onto yeast cake and as Warren suggestions, controlling a berzerk ferment at ideal temps is important

pitching the right amount is also important. A nice pitching calculator can be found here http://www.mrmalty.com/pitching.php

ideally yeast want to be in a lag phase before taking off so that it can build up energy reserves so to enable a healthy ferment. You might find a bigger risk to autolysis, is that you might not reach your desired attenuation as the yeast run out of puff.

but as with most things brewing, also if your sanitation and temp control is sound then you should be right.
 
AndrewQLD said:
Yeast autolysis is a very real problem, and is linked to yeast handling and storage. If your yeast is healthy you will be unlikely to encounter this problem. Here is a good link with info on causes ect.
Yeast Autolysis

Cheers
Andrew
[post="129233"][/post]​

You find some great links Andrew - top read...

I repitch on a yeast cake only once - With the cost of dried yeast, or of a liquid yeast split into 10 starters, I see little reason to push the bounderies any further - saying that, I'm sure you could get a few more, if sanitation & care of yeast has been good.

Cheers Ross
 
AndrewQLD said:
Yeast autolysis is a very real problem, and is linked to yeast handling and storage. If your yeast is healthy you will be unlikely to encounter this problem. Here is a good link with info on causes ect.
Yeast Autolysis

Cheers
Andrew
[post="129233"][/post]​

Oh, no doubt it's a real problem, that said so are so many things in brewing. Myself I've repitched onto yeast cakes often and never encountered a problem. Also must state that different strains may produce different results. ;)

Repitching your wort onto a 2-3 week old yeast cake (as is T.D.'s original question) should not be an issue though.

Like I said, there's no guarantees in a perfect world. Realistically speaking as homebrewers we're a little behind the 8 ball regardless.

That said reading articles written for the Microbrewing industry we can glean some real facts and 'some' may help us. :)

Warren -
 
AndrewQLD, like Warren, I wasn't saying that autolysis was a myth or anything, just that it may be like the many other things in brewing that are much more prevalent in "theory" than in "practice". It most certainly exists, but it may not be as common, or as easily contracted, as the theory implies. Its the same for things like HSA, the theory implies that if you splash your hot wort that it will always adversely affect your wort quality. I myself have been guilty of some pretty bad splashing of hot wort in the past, and have never come across any of the adverse effects predicted by the theory.

But anyway, I digress...

Thanks for the help guys. I might try the bock on the yeast cake and then not risk any more after that. No issues with sanitation so far - both beers that have been on that yeast cake are shaping up nicely - so hopefully the bock will also be problem free. :)

Cheers :beer:
 
On a related note . . .

How long do you feel it is safe to wait until pitching on top of the yeast cake like that?

What I mean is, should I have the next brew ready to be pitched on top just a few minutes after emptying the primary, or is it safe to keep the cake sitting in the fermenter for hours or even days after having racked?

If it is - should the fermenter just be refitted with the yeast lock so that any pressure that might build can get out, or would that be so limited that you can just plug it tight?

And lastly . . where would you put the fermenter? Would it benefit it to be kept cool or would keeping it at the temperature you would ferment at be the best thing? (I only really brew with ale yeasts for slightly higher temperatures myself).

Hope to hear. :)

Cheers,

Jens-Kristian
 
JK,

If I want to re-use the cake after racking or kegging, I just give the fermenter a good swirl so everything is basically back in a solution, then drain it off out the tap into a sterilised container. I just pop it in the fridge until I'm ready to use, and at times have left them for up to a week 'as is'. If I want to store some for a longer period then wash it with sterile water.

Cheers.
 
If I am going to re-pitch I limit it to once only as Ross says yeast isn't that expensive if treated right. I did repitch twice once and the third beer that came out of the yeast ended up on the garden :( I can't definately pin it on the yeast but I don't feel its worth the risk when making a nice clean starter is not so bad.

As far as how long to leave it well I would try and keep the beer on it until I am brewing the next beer. If the first is fully fermented then I usually dorp the temp to 3degC or something to keep the yeast dormant. Rack the beer into a keg and pitch on it within a couple of hours. If you are going to leave it longer then I would do what Duff has said but I wouldn't leave it longer than a few days or a week or why not just make a new starter.
 
I do exactly the same as JasonY

Cheers Ross.
 
Ditto JasonY and Ross.

Repitching on a yeast cake once is my limit and hasn't caused any deleterious results to flava.

I find it suits my brewing regime,ie one light and then one darker beer, b4 a new style or yeast choice.
 
Brauluver said:
Ditto JasonY and Ross.

Repitching on a yeast cake once is my limit and hasn't caused any deleterious results to flava.

I find it suits my brewing regime,ie one light and then one darker beer, b4 a new style or yeast choice.

[post="129594"][/post]​


I agree for ales. For lagers, you have to weigh up the potential problems with the large advantage of having a huge yeast count to start off and being able to pitch and ferment at a nice low temp. For lagers, I buy one yeast, one bag of malt, and go through the whole bag of malt continually repitching on either the whole or maybe a third of the previous cake. Only have to muck around making large starter for the first one then.
 
GL,Its good to see that sort of feedback on REAL results.
I was warned off repitching when I first broached the idea with other experienced brewers.Subsequent research online led me to the conclusion that many people(US especially)were practising this method with no problems.Ray Mills also extolled the virtues of it in an old thread.That was good enough for me to give it a go,and 12 months on I've found no reason to give up this method.
 
I don't get overly concerned reusing a yeast cake, and I'll do so if I have a wort ready to go and I want to use the same style of yeast.

Until recently this has been rare though, now with the retirement of my immersion chiller and with the plastic cubes stepping up to the mark I'm finding I'm doing this more often. I've never done it more than once but am planning on reusing a cake twice with the series of wort I've got waiting in the production line. I'm also going to collect a beaker full for a mate who I've given a cube full porter wort to for his efforts with solder ing my new mash tun mainfold recently.

In the past I've transferred the green beer from fermenter to keg then dumped my cooled wort in the same fermenter. I then airated with the "shake the shit out of it" method. This has the effect of knocking a lot of the protein ring from the krausen off the side of the fermenter. I was really concerned the first time this happened as I read it can cause off flavours. However this was not the case, so I've not worried too much about this consequently.

Scott
 
Guest Lurker said:
I agree for ales. For lagers, you have to weigh up the potential problems with the large advantage of having a huge yeast count to start off and being able to pitch and ferment at a nice low temp. For lagers, I buy one yeast, one bag of malt, and go through the whole bag of malt continually repitching on either the whole or maybe a third of the previous cake. Only have to muck around making large starter for the first one then.
[post="129600"][/post]​

The batch that fed the lawn was in fact a lager so i was doubley pissed off with it. I agree that the amount of yeast is a real advantage for a lager but given it takes 2 weeks of fridge time for a ferment I want to be sure the yeast is tip top.

Paranoid I am sure :wacko: only one re-pitch I say!
 
T.D. said:
So, everybody says, "don't leave a beer sitting in the primary fermenter for longer than 2-3 weeks" because you may subject yourself to autolysis.

For my last lager, I couldn't bring myself to throw out all that nice yeast sludge (Saflager 34/70), only to brew another lager and have to pitch 2 new sachets on it. Surely the yeast cake left from the previous lager would be like a "super starter". So I pitched my latest lager on the yeast cake and it went like a dream, tastes great out of the fermenter etc etc. I now have a bock that I want to ferment. Its obviously high gravity, so a good dose of yeast is preferred. At this stage I am going to pitch the bock on the yeast cake, which will make it the third brew in a row on that yeast.

Am I subjecting myself to autolysis by doing this? Is what I am doing sort of like leaving a beer sitting in primary for 6 weeks (3 brews X 2 weeks each)?

How many times can you safely pitch a new brew on the yeast cake of an old one?
[post="129222"][/post]​
One of the good things about homebrewing is you can push the limits and decide how far to go. Autolysis seems to be discussed a bit but I can only ever remember tasting one homebrew from a newbie that might have been affected that way.

I generally don't repitch (although I probably will this weekend). In the past I have had hop flavour carryover after starting with a hoppy brew (APA) which I probably should have expected.
 

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