Very crappy Attenuation on Imperial Stout

[roofjump]

As the subject says, brewed an Imperial Stout with the recipe below. Gravity started out at 1.083 which was right where I expected it to be. Problem is, after fermentation was done it only dropped to 1.030. The Irish Ale yeast was QUICK and very aggressive. It was also done with a starter, so I'm pretty sure I had enough yeasties for the job.

The beer was done fermenting in 4 days, but I left it a week just to be safe. After that week, it was dead. No bubbling whatsoever. Anywho, I'm kinda confused and disappointed that it didn't come out with the higher ABV. Any ideas? Should I pitch more yeast?

Extracts:
6.6 lbs Unhopped Dark Malt Extract
3.3 lbs Amber DME

Grains (Milled)
1 lb Chocolate Malt
1/2 lb Black Patent Malt
1/2 lb Munich Malt
1 lb Roasted Barley

Hops: Bittering -
(60) 2 oz Northern Brewer
1 oz Chinook Flavoring -
(30) 1oz Cascade Finishing -
(10) 1oz Fuggles

Yeast:
WLP004 Irish Ale Yeast

 

[Southwood]

Did you aerate your wort? I had similar problems until I got an oxygen system to aerate my wort. Since then I've come close to my target FG's.

Not sure if more yeast would help your current batch or not.

 

[roofjump]

Yes on the aeration.... I think.

I basically chill the wort to 70ish degrees, then pour it into the fermenter (6gal carboy) splashing it around. Then I pitch the yeast, put some plastic wrap on the top and shake the living crap out of it. I don't think the yeast had any lack of oxygen by the way it fermented, but I guess it's possible. This beer went nuts in the fermenter.

 

[_Edge]

I listened to podcast of basic brewing radio and they were talking to a guy (can't remember who or where from now). He said that their research showed that aggressively shaking your wort in the fermentation vessel for 4 minutes will yield about the same dissolved oxygen as an aeration stone for 30 minutes (don't quote me on the exact time). The point is that you really need to shake that baby up.

my strategy is to set a timer for 5 minutes (4 minutes plus breaks) and shake that fermenter as hard as I can, with respect to safety and not blowing off the lid of a plastic bucket. By the end, I am really sweating.

 

[Evan!]

I wouldn't be so disappointed in that. I tend to appreciate higher FG's in stouts. I know, the ABV (7%) isn't optimal for an Imperial, but if there's any beer out there that can handle that much residual sugars, it's a stout (or b-wine).

The other thing to note is that beers dry out with time...so even if it is too sweet for you when you bottle it, give it 6 months and it'll probably be sublime.

By the way, do you have any idea of the brand of the extract? If it was Laaglander, that might account for some of the residual sugar, as Laaglander tends to have more unfermentables than some other extracts. That's also alot of dark grains, and I'm not sure how fermentable those roasted grain sugars are. Seriously...um, that's another problem, now that I look at it. Your dark grains are way out of proportion. I did the SAME thing a few months ago---I made a stout where 22% of my grain bill was dark grain (patent, chocolate, roasted barley, etc.). To this day, the stuff is barely drinkable. It needs at LEAST 6 more months of bottle aging to mellow out. I mean, harsh as HELL. A big fat sack of tannins. Just be prepared for that. If you're a kegger, you may want to bottle this batch, as you don't want it hogging a keg for 6-12 months.

 

[roofjump]

I listened to podcast of basic brewing radio and they were talking to a guy (can't remember who or where from now). He said that their research showed that aggressively shaking your wort in the fermentation vessel for 4 minutes will yield about the same dissolved oxygen as an aeration stone for 30 minutes (don't quote me on the exact time). The point is that you really need to shake that baby up.

my strategy is to set a timer for 5 minutes (4 minutes plus breaks) and shake that fermenter as hard as I can, with respect to safety and not blowing off the lid of a plastic bucket. By the end, I am really sweating.

Good to know. I love the basic brewing video casts. Do you happen to know which episode it was?

 

[FSR402]

Now here is a question, lets say that he did not get enough air into the wort and it has been 4 days. Can he put air in it now by shaking it up? Or is that a really bad idea?

I ask because I'm not getting the activity out of my brew that I thought I would. I did not shake the wort at all. I auto sypioned it from the pot to the bucket thru a strainer that was sitting on top of the bucket. When I was done there was a lot of foam on top of the wort that I scraped off with my spoon before taking a OG.
Then I pitched the dry yeast and stired it for a few minutes and capped it up.

 

[roofjump]

I wouldn't be so disappointed in that. I tend to appreciate higher FG's in stouts. I know, the ABV (7%) isn't optimal for an Imperial, but if there's any beer out there that can handle that much residual sugars, it's a stout (or b-wine).

The other thing to note is that beers dry out with time...so even if it is too sweet for you when you bottle it, give it 6 months and it'll probably be sublime.

By the way, do you have any idea of the brand of the extract? If it was Laaglander, that might account for some of the residual sugar, as Laaglander tends to have more unfermentables than some other extracts. That's also alot of dark grains, and I'm not sure how fermentable those roasted grain sugars are. Seriously...um, that's another problem, now that I look at it. Your dark grains are way out of proportion. I did the SAME thing a few months ago---I made a stout where 22% of my grain bill was dark grain (patent, chocolate, roasted barley, etc.). To this day, the stuff is barely drinkable. It needs at LEAST 6 more months of bottle aging to mellow out. I mean, harsh as HELL. A big fat sack of tannins. Just be prepared for that. If you're a kegger, you may want to bottle this batch, as you don't want it hogging a keg for 6-12 months.

Yea, I'm a kegger, maybe I'll end up bottling this one *sigh*

The extract was the bulk stuff from my LHBS, maybe i'll ask the guy what brand it is.

I was afraid of all the dark grains, but figured that with all the extract I'd be alright. Oh well.

 

[david_42]

By the way, did you just steep the grains? You'll have a fair amount of unfermentables from the dark grains and Munich needs to be mashed. You could have extra 15 points right there.

 

[roofjump]

By the way, did you just steep the grains? You'll have a fair amount of unfermentables from the dark grains and Munich needs to be mashed. You could have extra 15 points right there.

Yes, I steeped the grain for 30min @ 150deg.

Sounds like I'll chalk this one up to not looking at the recipe more carefully.

 

[Southwood]

Now here is a question, lets say that he did not get enough air into the wort and it has been 4 days. Can he put air in it now by shaking it up? Or is that a really bad idea?.

I'm no expert on the subject, but I know that aeration after fermentation is BAD. If it's been 4 days I'd just let it run its course.

About the "too sweet stout", I agree with Evan. Time is key, I brewed a RIS last summer that I thought was too sweet after a couple weeks in the bottle. 6 months later it was delicious, now, almost a year later it's absolutely fantastic, smooth & roasty with an almost port-like qualiy.

Bottle it, age it, and RDWHAHB!

Cheers!

 

[_Edge]

Good to know. I love the basic brewing video casts. Do you happen to know which episode it was?

No, sorry I can't remember. If I did I probably would have gone back and listened to it. It wouldn't hurt to send those guys an email. generally they are very helpful.

 

[_Edge]

Now here is a question, lets say that he did not get enough air into the wort and it has been 4 days. Can he put air in it now by shaking it up? Or is that a really bad idea?

I ask because I'm not getting the activity out of my brew that I thought I would. I did not shake the wort at all. I auto sypioned it from the pot to the bucket thru a strainer that was sitting on top of the bucket. When I was done there was a lot of foam on top of the wort that I scraped off with my spoon before taking a OG.
Then I pitched the dry yeast and stired it for a few minutes and capped it up.

Again, Basic Brewing (I believe) mentioned that aerating after about 12 hours could introduce more oxygen than you want. I think I would be comfortable shaking it up the same day, but after it has sat overnight, I don't think I'd want to touch it.

 

[FSR402]

Again, Basic Brewing (I believe) mentioned that aerating after about 12 hours could introduce more oxygen than you want. I think I would be comfortable shaking it up the same day, but after it has sat overnight, I don't think I'd want to touch it.

Ok thanks. I think I'll just leave it be and hope for the best... Need to get another batch going so that I will have something coming right behind it if this one goes south.

 

[DraconianHand]

I believe the episode of BBR was August 24, 2006 - Going Big: Life After 1.064.

Link

 

[LBbrew]

i listened to that basic brewing episode not too long ago. I thought it was one of the episodes with the Wyeast guy.

 

[Vermicous]

I can only speak for myself, but whenever I do a big beer I try to leave it in primary for at least 2 weeks if not three. After the initial vigorous fermentation, it always slows to nothing. Hydrometer tests over the second week have shown that there is still some yeast active, even if they are barely putting out CO2.

 

[DraconianHand]

i listened to that basic brewing episode not too long ago. I thought it was one of the episodes with the Wyeast guy.

In the Going Big 1.064, aerating the wort within the first 12-24 hours with an airstone was discussed. The man interviewed was from Breiss.

 

[LBbrew]

ahhh ok. I was thinking of a diff but somewhat related one. The wyeast guy talked about pros and cons of o2 airstone vs. fish tank airstone vs. shaking vs. vigorous pour, etc. It was pretty good stuff.

 

[coyote]

LBbrew,

what was the Cliff Notes version of that podcast?

what's the deal with those podcasts...pay site?

thanks.

 

[FlyingHorse]

...shaking your wort in the fermentation vessel for 4 minutes will yield about the same dissolved oxygen as an aeration stone for 30 minutes (don't quote me on the exact time).

Oops, I quoted you on the exact time.

Do you mean 30 seconds with a stone? Seems to me that if shaking were that much more efficient than a stone, HBS's would be selling a lot more carboy shakers and a lot fewer 02 stones...

 

[methoddman]

haha lol

 

[LBbrew]

LBbrew,

what was the Cliff Notes version of that podcast?

what's the deal with those podcasts...pay site?

thanks.

I think it was this one.
--------------------------------------------
April 5, 2007 - Yeast Life Cycle
David Logsdon from Wyeast takes us through the life cycle of our favorite microorganism and lets us know how we can help our yeast thrive and make great beer.
--------------------------------------------

and you have PM.

 

[CBBaron]

First I think what you want to be concerned about as far as flavor goes is FG and attenuation. ABV should not be a primary consideration with beer.
Second 1.030 is a little high but will probably make a good stout if it is truly finished. If you are concerned you may try bringing the temp up a little to see if that helps.
With an RIS I think I would have left it in the primary for atleast 2 weeks and leave it sit in the secondary for 3 weeks or more. You may get it to drop a few more points in that time.
If some or all of your extract was Laaglander then you used an extract that has poor attenuation and you are very likely done.
If you do have a stuck fermentation then maybe some other experts can help.
Craig

 

[Rhoobarb]

I don't think it is lack of aeration or your yeast. I think Evan and David hit it on the head! The amount of unfermentables from all those dark grains are very likely what's giving you a 1.030 FG. Let it condition for a long time and see if it drops a bit and mellows. I seriously doubt that it will drop more than a scant few points, but it might make for a nice, creamy stout - very RIS-like.

My only concern is the same as Evan's - you may have a lot of tannins from all those dark grains. Just wait it out and see. I did something very similar once several years ago with a Porter and the beer was only good for marinades and cooking! So, don't feel like the Lone Ranger here!

 

[_Edge]

Oops, I quoted you on the exact time.

Do you mean 30 seconds with a stone? Seems to me that if shaking were that much more efficient than a stone, HBS's would be selling a lot more carboy shakers and a lot fewer 02 stones...

Found the episode -- 11/2/05 Second Interview with Dave Logsdon of WyeYeast. The conversation begins at about 15:30.

The money quote is around 21:10, Dave: "we found that shaking actually works better than an aquarium pump... we did some studies on it and I think it was only about 4 minutes of good heavy shaking gave us enough dissolved oxygen for a typical gravity beer."

you can download all of the episodes (for free, at least it was for me a few months ago) from the itunes podcast list.

 

[roofjump]

cool, thanks again guys. I just got all of the equipment together for my first All-grain

Maybe I'll revisit this recipe once I figure out how to not screw up an AG batch