Alcohol tolerance of yeast

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Biermann

Reinvented Biermann
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Curious question--

I have a mod-high gravity ale (winter welcome--A.G., 12 gallons) that isn't reaching its FG. I pitched an appropriate count of Safale S04, and it only dropped the gravity from 1.078 to 1.026. It was an otherwise brisk, healthy fermentation that actually needed a blow-off.

I have heard that S04 doesn't have that great of an alcohol tolerance, so I was thinking of pitching some Nottingham that I have available vs going out and getting some Champagne yeast to finish it off. I'm hoping to get this beer around 1.012 or so. I also don't want to screw up the flavor, but I'd like the beer reasonably dry-- so I need to pitch something with a good alcohol tolerance and a clean flavor profile.

I doubt this beer is going to be that dextrinous since the mash was at the lower end of the diastase rest, and was held about 90 minutes, so I'm thinking the poor attenuation is due to alcohol intolerance.

Thoughts, suggestions??
 
From 1.078 to 1.012 is around 84% attenuation, that's Belgian style high. If you used the champagne yeast it would probably do that, might make it even drier. Have you tried gently swirling the carboy to suspend the yeast again? There might not have been enough oxygen to get the yeast trough, they could have just become tired and flocculated. I don't think the low attenuation is due to alcohol intolerance, there are so many other factors that could have influenced the FG that it can be hard to pin point.
 
I did one other beer (a stout) with a slightly lower OG (1.072), and the same yeast, and it only got down to 1.020. I've done many other beers with the same gravity range with different yeasts, similar techniques, all with good attenuations.

That's the only reason I deduced it to be due to a low EtOH tolerance.

That said, I've never added Champagne yeast to any beer before, so naturally I'm a bit suspicious of using it.
 
Iordz said:
From 1.078 to 1.012 is around 84% attenuation, that's Belgian style high. If you used the champagne yeast it would probably do that, might make it even drier. Have you tried gently swirling the carboy to suspend the yeast again? There might not have been enough oxygen to get the yeast trough, they could have just become tired and flocculated. I don't think the low attenuation is due to alcohol intolerance, there are so many other factors that could have influenced the FG that it can be hard to pin point.

Of course, " Belgian style high" may not be so bad for this beer-- afterall, it is meant as a winter warmer. . :mug:

Oh, and I aerated with a stone for more than 15 minutes.
 
Are you using pure oxygen, or an aeration pump? Pure O2 only requires 60-90sec, whereas aeration systems need 60-90min. Most winter beers I've had seemed to be full bodied and a little sweet, with a hint of alcohol.
 
I used an air pump for this one. Didn't have my O2 tank handy.

I had to stop aerating it because of the huge snake of foam coming out the top.
:) I generally aerate most of my beers around 15-20 minutes (as I'm pumping the wort into the fermenter, and then some). It may actually be longer than that, but not 60-90 minutes.
 
I do 60min of oxygenation, at times I have to stop and allow the foam to sink, then I continue. The problem is once the gravity is over 1.059 it becomes really hard for the oxygen from air to dissolve into the wort, that's why it's best to use pure oxygen for about 90sec, that way you get the proper amount of oxygen dissolved and the yeast can grow happily. That was probably your problem, there was too little oxygen available. If you want to go further down in gravity pitch some champagne yeast.

http://www.howtobrew.com/section1/chapter6-9-2.html
I quote, John Palmer, "using a bronze or stainless steel airstone with an aquarium air pump and using it to bubble air into the fermenter for an hour."
 
Iordz said:
I do 60min of oxygenation, at times I have to stop and allow the foam to sink, then I continue. The problem is once the gravity is over 1.059 it becomes really hard for the oxygen from air to dissolve into the wort, that's why it's best to use pure oxygen for about 90sec, that way you get the proper amount of oxygen dissolved and the yeast can grow happily. That was probably your problem, there was too little oxygen available. If you want to go further down in gravity pitch some champagne yeast.

I'm going to give it yet awhile longer and bleed the yeast off. If the gravity is still up, I may pitch some Champagne yeast. I haven't thoroughly made up my mind yet.

I don't like having the gravity where its currently at, yet I don't want to introduce any weird flavors or get it TOOO dry.

Thanks for the input.
 
No problem! I had a smoked porter finish at 1.020, and boy was it sweet and not in a good way.
 
Iordz said:
Are you using pure oxygen, or an aeration pump? Pure O2 only requires 60-90sec, whereas aeration systems need 60-90min.

I've never used pure oxygen, but these times just don't seem to sync up. The air we breathe is 21% oxygen. Hence, I can see an oxygenation with air lasting 5x as long (5-7min) or even 10x as long (10-15 min), but 60-90x as long?
 
I'm sure its not exactly a linear relationship, but with a nice diffusion stone (which I have), I can't see why you couldn't get an acceptable amt of O2 in solution in 15-20 minutes. . .which anyway, O2 is only needed for the aerobic phase of yeast growth. Fermentation, by definition, is an anaerobic process.

We're digressing into theory here, and not getting at the questions at hand, and I definately don't want to get into any arguments here-- Lord knows I've been wrong before, and could easily be wrong on this one.

So, to recap:

1. Anyone else ever have S04 quit fermenting around 7 % or so?
2. What can I expect from Champagne yeast flavor-wise?
3. I've heard Nottingham has about an 11% alcohol tolerance, but only from one source--I have this on hand, and am thinking of pitching this.

Thanks
 
Champagne yeast is slow, but it has very high alcohol tolerance and adds zero flavor. Just keep sampling and hit it with some campden when it's where you want it.

I haven't seen an official rating for Nottingham, but I used it in a big IPA (1.084) and got good attenuation. (This was a cake from a Brown)
 

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