# s-04 and diacetyl



## micblair (14/2/14)

I've used this yeast a few times, however recently tried re-packaged yeast from Keg King which comes in a 15g package Pitched into well oxygenated wort (1.044), cooled to 18C and allowed to free rise to 22C. Fermentation was done in approx. 3 days (1.012 final), however this beer has a distinct diacetyl problem, which seems to intensify when allowed to warm up in a glass . I'm unsure if its bacterial related (beer doesn't taste sour yet) or characteristic for this yeast. Racked to a keg and now its sitting at 20C awaiting for the diacetyl to clear. Considering bottling to see if this helps resolve this issue...


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## stakka82 (15/2/14)

Did it floc properly?


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## durgarth (15/2/14)

I rarely respond to posts, but since none of the brains trust seems to be responding I thought I might throw in. Repackaged yeast should not be a problem. Its very hard to infect a yeast in its pure form (although by no means impossible). My thoughts is that it picked up a bug from elsewhere. 

Please take it the right way.......are you sure your basic hygiene in brewing was right? Did you follow you usual procedure? 

The second point is to brew again using the same bucket and system (after your usual cleaning methods). If it turns out "funky" ditch it and the bucket. Then work backwards to identify he source. Good luck with this I have been through the same problem several times and am still to identify the bloody garden hose flavour which seems to have got into my brewery (intermittently).


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## micblair (15/2/14)

Yeah it floccd immediately.

Fermented in a glass Carboy. I've done 4 brews this month
First time using s-04, first time to give me grief.


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## Edak (15/2/14)

I have a brew in the fermenting fridge right now using same repackaged yeast from kk and it's diacetyl city! Finished in 3 days, 18c constant, good damn. Going to leave in there for a few weeks to see if it disappears. My sanitation is excellent. This is my first time using s04 and not leaving a good impression so far.


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## Donske (15/2/14)

Edak said:


> I have a brew in the fermenting fridge right now using same repackaged yeast from kk and it's diacetyl city! Finished in 3 days, 18c constant, good damn. Going to leave in there for a few weeks to see if it disappears. My sanitation is excellent. This is my first time using s04 and not leaving a good impression so far.


I gave up on S-04 a while ago, it's just too damn finicky, ferment too low it's diacetyl and stuck ferments, too high and it throws bubblegum, an absolute prick of a yeast.


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## pedleyr (15/2/14)

Donske said:


> I gave up on S-04 a while ago, it's just too damn finicky, ferment too low it's diacetyl and stuck ferments, too high and it throws bubblegum, an absolute prick of a yeast.


I've read a lot of people with similar experiences, but in my admittedly limited experience with it - just 5 brews - I can't report sharing that. Perhaps I'm lucky enough to have very good temperature control that makes it easier for me, but two of those brews (same recipe) are the best beer I've ever made, which I credit the yeast with a great deal of. 

The fermentation was a little slower with a couple but never stalled, a little faster with a couple, and there's no diacetyl that I can detect (but a more advanced palate may be able to), likewise bubblegum. 

What type of beers did you use it in?


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## Dips Me Lid (15/2/14)

micblair said:


> I've used this yeast a few times, however recently tried re-packaged yeast from Keg King which comes in a 15g package Pitched into well oxygenated wort (1.044), cooled to 18C and allowed to free rise to 22C. Fermentation was done in approx. 3 days (1.012 final), however this beer has a distinct diacetyl problem, which seems to intensify when allowed to warm up in a glass . I'm unsure if its bacterial related (beer doesn't taste sour yet) or characteristic for this yeast. Racked to a keg and now its sitting at 20C awaiting for the diacetyl to clear. Considering bottling to see if this helps resolve this issue...


What was your batch size, did you have the correct pitching rate?

I've only ever made a couple of English Milds with s-04, I and found it produced a fair amount of diacetyl, after primary was completed at 19c I roused the fermentor and gave it a diacetyl rest for 7 days at 21c, seemed to clear up most of it.

If you've racked the beer off the yeast into a keg a diacetyl rest might not achieve much without enough active yeast.


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## micblair (15/2/14)

Yeah, the glass carboy is pretty unruly when it comes to moving, storing and the prospect of light strike etc, hence moving it
into a keg. 
Since the bulk of the yeast was already floccd, I was really relying on the yeast left in solution to reduce diacetyl. 
Given the activity of fermentation and the final temperature, under normal circumstances, diacetyl should have been gone.
Going to bottle condition this one and see how things work out. Reassuring to hear others have had unusual results re. Repackaged yeast from kk (all other repackaged stuff has worked fine for the record).


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## micblair (15/2/14)

Dips Me Lid said:


> What was your batch size, did you have the correct pitching rate?
> I've only ever made a couple of English Milds with s-04, I and found it produced a fair amount of diacetyl, after primary was completed at 19c I roused the fermentor and gave it a diacetyl rest for 7 days at 21c, seemed to clear up most of it.
> If you've racked the beer off the yeast into a keg a diacetyl rest might not achieve much without enough active yeast.


21L, 15g of S-04


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## Dips Me Lid (15/2/14)

Well that would rule out underpitching I guess, I'm not that familiar with s-04, only used it couple of times but a long diacetyl rest seemed to work for me.


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