Yeast giving up on high gravity beer

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ChrisVZ

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Over the past year, I have attempted to make 3 beers with an OG over 1.080. Every time, my yeast seems to give up any where from 1.030 to 1.025. I am aerating well(pouring between buckets 8-10x), maintaining my tempratures, and using starters with no luck. My normal beers all turn out great, rarely finishing above 1.015. The mead that I made several months back started at 1.098 and finished at 0.997 with no issues. The only difference I can think of is that I degassed the mead frequently during primary by swirling the bucket. Is this something I should be doing with the beer, or is there something else I should be looking at?
 
maybe you have too many unfermentables in the bigger OG beers you are taking about... Mashing too high or having a large crystal % in the beer?
 
Its not a mashing issue as they are extract kits. I havent upgraded to all grain yet. All have used less than 2# of steeping grains. I did a full boil and added all my extract in the beginning. Maybe my sugars caramelized during the boil? I may be grasping at straws with that, but I can't see what else I could be doing wrong. It's starting to get expensive making beer I can't drink.
 
Are your starters big enough? Check yeastcalc.com or mrmalty.com to make sure you're pitching enough yeast. I also recommend getting a pure oxygen set up for oxygenating the wort. At that high of an OG the yeast needs a lot of oxygen and your current method may not be providing enough. Also, at what temperatures are you fermenting? Too low and the yeast may drop out early. Once the bulk of fermentation is done, bring the temp up to 70 & swirl the fermenter to keep the yeast in suspension. Might try adding yeast nutrient as well but be aware of over attenuation. I had a high gravity tripel dry out too much using nutrient.
 
What yeast(s) are you using? Have you considered using some simple sugars in place of a small portion of extract? That will help with attenuation.
 
Are your starters big enough? Check yeastcalc.com or mrmalty.com to make sure you're pitching enough yeast. I also recommend getting a pure oxygen set up for oxygenating the wort. At that high of an OG the yeast needs a lot of oxygen and your current method may not be providing enough. Also, at what temperatures are you fermenting? Too low and the yeast may drop out early. Once the bulk of fermentation is done, bring the temp up to 70 & swirl the fermenter to keep the yeast in suspension. Might try adding yeast nutrient as well but be aware of over attenuation. I had a high gravity tripel dry out too much using nutrient.

THis. High gravity beers need more oxygen than there is in room air - in other words, no amount of shaking/splashing will introduce enough O2 into the wort, and you need to add pure O2 to make the yeast happy.

As an alternative, you could try pitching on a yeast cake from a modest gravity beer. O2 is needed so that the yeast can reproduce. If you pitch high gravity wort onto a yeast cake, the yeast is already at a sufficient volume to ferment the high gravity stuff.
 
Also, pitching on a yeast cake works for new beers, as well as the one you have right now. You can leave your underattenuated high gravity beers sitting in the fermenter and make a modest gravity beer. Rack the underattenuated beer onto the yeast cake when the modest grav beer is done, and new fermentation will start - most likely, it'll finish out and reach the expected final gravity.
 
As an alternative, you could try pitching on a yeast cake from a modest gravity beer. O2 is needed so that the yeast can reproduce. If you pitch high gravity wort onto a yeast cake, the yeast is already at a sufficient volume to ferment the high gravity stuff.

Being in the same boat and having issue as the OP my next RIS will be tossed on top of a yeast cake to get things going better and longer.

If no yeast cake is available it will get a big honkin starter for sure.
 
Seems the consensus is not enough O2 for the yeast. A pure O2 setup isnt in my budget at the moment, but I think on my next batch, i will try a multi stage starter to get their population up. I also have some yeast nutrient that I used in the mead that I can use. If these fail, I will try using a yeast cake. Thanks for the input guys.
 
ChrisVZ said:
Seems the consensus is not enough O2 for the yeast. A pure O2 setup isnt in my budget at the moment, but I think on my next batch, i will try a multi stage starter to get their population up. I also have some yeast nutrient that I used in the mead that I can use. If these fail, I will try using a yeast cake. Thanks for the input guys.

You could also do a 2.5 gallon batch as your "starter" and then bottle and drink it, rather than decanting and pouring away lots of starter wort. Just my $0.02. Cheers!
 
It might be more affordable than you think. $19.90 for a regulator from Williams Brewing, .5 micron diffusion stone from wherever - about $13 or so, some hose and about $10 for a disposable O2 tank from your local hardware store and your all set.

I wouldn't even try to brew a high gravity extract batch without an oxygen set up. I don't mean to discourage you but I once did a partial mash barleywine that I pitched onto a yeast cake AND used pure O2 and it STILL didn't get down to where I wanted it. I'm certain it's because I didn't hit it with enough O2.
 
It might be more affordable than you think. $19.90 for a regulator from Williams Brewing, .5 micron diffusion stone from wherever - about $13 or so, some hose and about $10 for a disposable O2 tank from your local hardware store and your all set.

I wouldn't even try to brew a high gravity extract batch without an oxygen set up. I don't mean to discourage you but I once did a partial mash barleywine that I pitched onto a yeast cake AND used pure O2 and it STILL didn't get down to where I wanted it. I'm certain it's because I didn't hit it with enough O2.

Yeast only need the O2 to reproduce, correct?

If so, wouldn't it stand to reason that you still just need to pitch at a higher rate?

Honest questions...I am looking for some education like the OP.
 
I disagree with the need for pure O2. Every beer I've brewed has been extract and most of my big beers (>1.105) finish in the mid to upper 1.020's. I've had two beers finish over >1.030; one had a pound of lactose and the other had a 1.116OG. I didn't add sugar to dry them out because I like my stouts malty.

I agree with the use of yeast nutrient. I just started doing it and brewed two identical quads. The second one finished .007pts drier and the only difference was I added yeast nutrient to it.
 
Yeast only need the O2 to reproduce, correct?

If so, wouldn't it stand to reason that you still just need to pitch at a higher rate?

Honest questions...I am looking for some education like the OP.

Could be, makes sense that more yeast means you don't need as much dissolved o2 in the wort but I don't know. i'm going to have to dig into the "Yeast" book.
 
Gonna try another beer (11lb. of fermentables) this weekend or early next week. I'm gonna do a 1 1/2 qt starter to get the yeasties going and then to a 3/4-1 gal starter, both with yeast nutrient and energizer. Crossing my fingers and hoping for the best.
 
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