Alcohol Tolerance Inquiry

[SeanS86]

Hi all,
I recently brewed an imperial stout with an original gravity of 1.120, by far the biggest beer I've ever done, and double pitched it with 2 packs of Wyeast American Ale (I was too lazy to make a starter) in the hopes that the yeast wouldn't get overworked and stop. I'd like the final gravity to end up around 1.035 or so, giving it around 11% abv, which is also the alcohol tolerance of the yeast. My question is, since I double pitched, will the yeast still give out around 11%, or will it go over? This may have a pretty obvious answer that is escaping me, but I've never done a beer this big before. It's on its 4th day and is bubbling just as hard as it was the first day, which I'm happy about, I just don't it to go overboard. Any thoughts? Thanks

 

[ksbrain]

I've found that yeast carries some momentum and can pass its rated ABV tolerance, but YMMV. I'd be concerned about bottle conditioning in your position.

 

[SeanS86]

really? why is that?

 

[ksbrain]

I made a few beers that went to the limit of the yeast - one Double Fat Tire that shut down in the fermenter at exactly 10.00% ABV and never came back to life to carbonate the bottles, and one Duvel clone that never finished its job. It's experiences like this that pushed me into kegging. Though I've read that you can add fresh yeast at bottling and that helps.

 

[Homercidal]

Kegging works good. Some people also use a higher tolerance yeast, like a wine or champagne yeast to finish with.

 

[bootney]

I just bottled an imperial ipa with similar starting gravity and final gravity. I also used two packs of wy american ale without starter. I will say I was not pleased with the outcome. I'm not sure if it was due to under pitching the yeast or what else happen in terms of flavor. It's been bottled for a week and I opened one up just to see how the carbonation was coming along and it's far behind anything else I've bottled. As others have mentioned due to decreased yeast cells you may experience difficulty with carb without adding more yeast during bottling. I'll try another bottle this weekend to see if I've made progress with carb and update otherwise I'm going to let this one sit a while to see if the carbonation improves as well as flavor.

 

[Homercidal]

I just bottled an imperial ipa with similar starting gravity and final gravity. I also used two packs of wy american ale without starter. I will say I was not pleased with the outcome. I'm not sure if it was due to under pitching the yeast or what else happen in terms of flavor. It's been bottled for a week and I opened one up just to see how the carbonation was coming along and it's far behind anything else I've bottled. As others have mentioned due to decreased yeast cells you may experience difficulty with carb without adding more yeast during bottling. I'll try another bottle this weekend to see if I've made progress with carb and update otherwise I'm going to let this one sit a while to see if the carbonation improves as well as flavor.

1 week?? LOL! That is hardly worth worrying about. Give it 3 minimum, and maybe more like 6. The flavor will change for the better, and it will carb up ok, as long as you used the right amount of yeast and mixed it well.

 

[SeanS86]

yeah 1 week is pretty early for the majority of beers, let alone a high gravity one. i planned from the onset to use about a half packet of US-05 or another neutral dry yeast at bottling, with 1/3 or 1/2 cup priming sugar. since my RIS is such a big beer i'm planning on letting it relax for at least 3 or 4 months before giving it a go anyway, so with the added yeast i'm sure it'll good and carbed by then.

 

[bootney]

Thanks for the replies and I do realize that one week is early from a sampling stand point. I think my point was missed in that my situation was similar to the op in that we did not use starters and our batches had about half the amount of yeast that was required. Thus leading to off flavors due to stressed yeast and perhaps issues with carbonation. All in all I do agree with the fact my batch needs a while to condition. I just opened after one week for the sake of comparison to other batches I brewed because my lower gravity beers had acceptable carbonation after one week in the bottle.

 

[bovineblitz]

1 week is nothing, my 6% stout took 5 weeks to carbonate recently. I'm sure it'll come along a little slower than your typical beer.

 

[Abadeon]

Hi all,
I recently brewed an imperial stout with an original gravity of 1.120, by far the biggest beer I've ever done, and double pitched it with 2 packs of Wyeast American Ale (I was too lazy to make a starter) in the hopes that the yeast wouldn't get overworked and stop. I'd like the final gravity to end up around 1.035 or so, giving it around 11% abv, which is also the alcohol tolerance of the yeast.

I had the same in a Imperial Stout made in Sept/09, reached 11% too, but the yeast died and there´s a lot of sugar remaining in the bottle. I made the primming but there´s no carb, after months, what proves yeast death.
There´s nothing to do but to use some of the bottles to cook meat. :rockin:

 

[Abadeon]

As others have mentioned due to decreased yeast cells you may experience difficulty with carb without adding more yeast during bottling. I'll try another bottle this weekend to see if I've made progress with carb and update otherwise I'm going to let this one sit a while to see if the carbonation improves as well as flavor.

The high ABV (11%) won´t halt the yeast increase in the bottle?

 

[MattHollingsworth]

I had the same in a Imperial Stout made in Sept/09, reached 11% too, but the yeast died and there´s a lot of sugar remaining in the bottle. I made the primming but there´s no carb, after months, what proves yeast death.
There´s nothing to do but to use some of the bottles to cook meat. :rockin:

You can open each bottle, pour in a very small amount of dry yeast and recap them, hold them at 70 or above F and they should carbonate up nicely. I've done it before and it works great.

 

[JLW]

Recently, I was talking with the folks at Austin Homebrew and they recommended anything above 1.090 OG to pitch 3 vials of the White Labs liquid yeast.

 

[Dave258]

Recently, I was talking with the folks at Austin Homebrew and they recommended anything above 1.090 OG to pitch 3 vials of the White Labs liquid yeast.

Save your money, and make a large starter.

 

[wendelgee2]

OP,
Even with "double pitching" with two pouches, you have underpitched wildly.
It will recover and eat everything up, but I'd be concerned about yeast health. Stressed yeast tends to produce fusels (and more esters, and other undesirables). I'm thinking you're going to have a pretty rough beer for at least a year.

Not that it's gospel, but I'd at least consult the pitching calculator on Mr. Malty to get a sense of what a healthy pitch of yeast is for a given gravity.