Author Topic: Is my fermentation stuck?  (Read 1099 times)

Offline colinhayes

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Is my fermentation stuck?
« on: November 28, 2010, 04:33:12 PM »
Hi all,

Recently did my 5th batch and I feel like my fermentation is stuck, and I need some help deciding whether it is time to pitch some champagne yeast or leave it be.  Beer is:
6 lb dark dme
2 lb light dme
1 lb smoke malt
1 lb chocolate malt
.5 lb black patent malt
.5 lb roasted barley
.5 lb maltodextrin
grains mashed w/ 3 gal. water at 145-150 for 60 min., boiled with 6 oz hops total, put into a 6.5 gal carboy at 70°, pitched wyeast 1098.  Starting gravity was 1.073.  In a day and a half it was down to 1.031 @ 72°F, after 5 days it was down to 1.021°F, and now 4 days after that it is still the same. 

Fermentation was pretty intense, and I think we lost about 1 gallon is foam out the blow-off tube.  Did we lose too much yeast in the blow-ff tube?  Is 1.021 too high of a final gravity for this beer?  I was hoping for it to get down to at least 1.013, but I'm not sure how much the maltodextrin is going to add to the final gravity.  For the past batches we've started at about 1.060 and ended at 1.010, and I feel like the maltodextrin wouldn't raise it THIS much.

Opinions?

Offline tubercle

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Re: Is my fermentation stuck?
« Reply #1 on: November 28, 2010, 04:37:48 PM »
It seems to be finished.

 More importantly...what possessed you to pitch @ 70F?
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Offline bluesman

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Re: Is my fermentation stuck?
« Reply #2 on: November 28, 2010, 04:50:13 PM »
There are some unfermentables in your grain bill so it may be finished although it sounds a little high for this recipe.
Have you tried calibrating your hydrometer?

The other thing I noticed is your pitching temp of 70F. I would recommend pitching ales in the low sixties. The fermentation process will warm up the beer several degrees.  While you will make beer...it is important to pitch low and ferment low in an effort to achieve a cleaner tasting ale.

Welcome to the AHA forum.

Good Luck!
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Offline colinhayes

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Re: Is my fermentation stuck?
« Reply #3 on: November 28, 2010, 06:22:20 PM »
what possessed you to pitch @ 70F?

well, charlie papazian's book, actually.  maybe he should update that... only temp advice I can find in it says to pitch once it's below 78°F.  I guess we'll try lower next time.

haven't tried really calibrating the hydrometer, but I but it in some cool water about a week ago and it was right around 1.000

Offline majorvices

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Re: Is my fermentation stuck?
« Reply #4 on: November 28, 2010, 06:25:25 PM »
First off, I would recommend almost never using Maltodextrine. There just is no real need for it. Most extract beers tend to end up under attenuated, not over attenuated, and maltodextrine is mostly unfermentable. Second - for extract beers, you should normally start with the lightest extracts available, and then add your color with specialty malts. Dark malt extracts tend to be mashed higher and tend to finish higher, and on top of that, you have no idea what the actual brewer of the extract did to get the malt the color it is (was it made with munich? chocolate? Roasted Barley? caramel malt? Who the hell knows?) At least with light malt extract you can pretty much assume it is a standard 2-row base, which is what most beers are anyway. The exception to this would be if you could find a 100% munich or vienna malt extract.

So, yeah, you are probably done. Lots of unfermentales in the grist. And you have no control over composition of the dark extract.
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Offline majorvices

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Re: Is my fermentation stuck?
« Reply #5 on: November 28, 2010, 06:27:47 PM »
BTW: Papazians book is a bit outdated. Pick up a copy of "How to brew" by John Palmer. That said, I love Papazian's books. Thats what I got started with. Also, 70 degrees is what I would consider border line warm picthing temp. But you certainly wouldn;t want the beer to ferment any warmer than this (and fermentation is exothermic: it will generate 6-8+ degrees over ambient temps. Temp control is also critical.)
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Offline jwaldner

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Re: Is my fermentation stuck?
« Reply #6 on: November 28, 2010, 08:13:23 PM »
You can use the following formula to calculate your attenuation and get a pretty close estimate to determine whether or not your yeast has finished.

[(OG – FG) / (OG – 1)] X 100

Checking the Wyeast site, for optimum fermentation you should get 73% to 75% attenuation for this strain. If you're starting OG was 1.073, you got about 72%, pretty good I think. For you to get it as low as you want you would have to get 83% attenuation which is not possible with this yeast strain. If you still want to try and bump it down a few points my suggestion would be to rouse the yeast a bit by shaking, give it 2-3 more days and see if it drops.

Cheers


Offline a10t2

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Re: Is my fermentation stuck?
« Reply #7 on: November 28, 2010, 08:35:53 PM »
I'd say 71% ADF is amazing considering the recipe was mostly dark extract. (Not to mention the maltodextrin.)

For you to get it as low as you want you would have to get 83% attenuation which is not possible with this yeast strain.

Not only is it possible, it's routine. Those attenuation stats are meaningless.
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Offline colinhayes

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Re: Is my fermentation stuck?
« Reply #8 on: November 29, 2010, 05:58:02 AM »
majorvices: 

This was our first attempt at a dark beer, so we didn't really know much about the dark dme.  My instincts said to go with more light for those reasons exactly, but we saw a few recipes that called for more dark, and figured we'd go with that.  We definitely had enough color just from the partial mash.  I'll drop the maltodextrin next time.  We added that in at the suggestion of a friend who used to brew dark beers a lot.

I've had a copy of palmer's book on request at the library for a couple of months now.  I wanted to check it out before buying it, but I'm getting a bit impatient at this point.  Apparently the Chicago public library has one copy and a lot of people who want it.

Live and learn.  Beer tastes pretty decent at this point though, I really like the smoke malt in there.  I just wish I could have had more alcohol in it than our others with 2 more lb of dme in it...

Offline tubercle

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Re: Is my fermentation stuck?
« Reply #9 on: November 29, 2010, 05:59:51 AM »
what possessed you to pitch @ 70F?

well, charlie papazian's book, actually.  maybe he should update that... only temp advice I can find in it says to pitch once it's below 78°F.  I guess we'll try lower next time.


 Now that the Sun has come up and a good night's sleep, Tubercle apologizes for the curt statement. I was the one possessed (by several stouts ;D).

  It is the consensus that yeast give better results at the lower end of the temp range as others have stated. The yeast would love nothing better than to be bathed in a warm, sugary, nutrient filled environment but our purpose on this earth is not for the comfort of the yeast but to make good beer. Even though there may not be any visible signs to us for 24 -36 hours like krausen and air lock bubbles, yeast start working as soon as they hit the juice. There are things that go on that can produce less than desirable results during this time, like excessive fusel alcohols, in too warm of an environment.

 If the preferred range is 65 - 75f for example, its better to start at 65f. It will warm up due to the activity as Majorvices explained. You can usually go about 5f lower also without stalling the yeast. This is my experience anyway.

 Welcome to the forum....
Sweet Caroline where the Sun rises over the deep blue sea and sets somewhere beyond Tennessee

Offline majorvices

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Re: Is my fermentation stuck?
« Reply #10 on: November 29, 2010, 06:14:11 AM »

Live and learn.  Beer tastes pretty decent at this point though, I really like the smoke malt in there.  I just wish I could have had more alcohol in it than our others with 2 more lb of dme in it...

In the end this is what is important. That said, I would recommend using light DME for the majority of your recipes, unless, as I stated, you can find a Munich extract. Normally that would be for German style dark beers though.

The thing to keep in mind is this: even a Russian Imperial Stout, which is a very opaque, dark beer, would normally be made with a light 2 row as the vast majority of the grist.

As far as the maltodextrine goes. Its a tool that can be used when needed. Personally I have never found an instance where it is needed. Some brewers may prefer their beer on the sweeter side and in this case that may be a good instance to use it. I personally do not care for overly sweet beers. Regardless, I recommend trying the brews without it and then if you want more sweetness or body add a little the next time.
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Offline tschmidlin

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Re: Is my fermentation stuck?
« Reply #11 on: November 29, 2010, 10:39:22 AM »
I've had a copy of palmer's book on request at the library for a couple of months now.  I wanted to check it out before buying it, but I'm getting a bit impatient at this point.  Apparently the Chicago public library has one copy and a lot of people who want it.
Try going to the How to Brew website.  http://www.howtobrew.com/intro.html

It's got the orginal version of the book, that should give you a good enough feel for the book to decide if you want to buy it.  The print version is updated though, and is worth it IMO.
Tom Schmidlin

Offline bluesman

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Re: Is my fermentation stuck?
« Reply #12 on: November 29, 2010, 10:43:36 AM »
I've had a copy of palmer's book on request at the library for a couple of months now.  I wanted to check it out before buying it, but I'm getting a bit impatient at this point.  Apparently the Chicago public library has one copy and a lot of people who want it.
Try going to the How to Brew website.  http://www.howtobrew.com/intro.html

It's got the orginal version of the book, that should give you a good enough feel for the book to decide if you want to buy it.  The print version is updated though, and is worth it IMO.

+1

Tom's advice is good...go online and check it out.
Ron Price