Stalled Fermentation on an Alt - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > Fermentation & Yeast > Stalled Fermentation on an Alt

Reply
 
Thread Tools
Old 09-22-2010, 02:40 AM   #1
AlchemyBrewing
Recipes 
 
Apr 2010
Denver
Posts: 92


I have an "Alt" that has an OG of 1.050 and fermented really nice for about 48 hours and then slowed way down. We let it go for another 5 days and the ferm lock was bubbling about once in 40 seconds. We assumed it was done and put the carboys in the fridge to cold crash them for a couple of days. We just went to keg them and we end up with a FG of only 1.020. It tastes pretty good but is no where near the 5%+ we were expecting. We are going to leave one keg and then take the other and try to do a secondary fermentation with out adding yeast or sugars. Is this a mistake and what else could we have done?

My brew-mistress is guessing that we did not have the right Mash temps. Any and all thoughts are really appreciated.
__________________
I AM ......LIFTING BOY!

 
Reply With Quote
Old 09-22-2010, 08:45 AM   #2

Am I understanding correctly that you cold crashed it after a total of 7 days and while there were still signs of active fermentation (the airlock was still bubbling every 40 seconds)?

If this is true, you cold crashed too early, stopping the fermentation before it was done. You needed to let the fermentation run until it was done, before cold crashing or kegging or bottling. 3 weeks would not be unusual. If you're not sure if fermentation is done, you can test it with a hydrometer - compare readings taken three days apart, if they are the same, then fermentation is done. If the airlock is bubbling then the yeast is still working.

If I misinterpreted your post, then yes, you might look at the mash temps - if your temps were higher than you wanted, you would end up with more non-fermentables in your wort, leaving you with a higher final gravity.

 
Reply With Quote
Old 09-22-2010, 02:36 PM   #3
AlchemyBrewing
Recipes 
 
Apr 2010
Denver
Posts: 92

Thanks Jim,
You are correct in your understanding. We were just working under the principals of folks like Papazzian that indicate after your yeast settles to the bottom and the activity has slowed considerably you are better off to pull the beer off the yeast bed and be done with it. We were taught that a 6 day fermentation is about it. I don't know if that is now old school and new theories have prevailed. Got any recommendations on updated books that are more current? Thanks again for the help!
__________________
I AM ......LIFTING BOY!

 
Reply With Quote
Old 09-22-2010, 02:42 PM   #4
Revvy
Post Hoc Ergo Propter Hoc
HBT_LIFETIMESUPPORTER.png
 
Revvy's Avatar
Recipes 
 
Dec 2007
"Detroitish" Michigan
Posts: 40,925
Liked 3201 Times on 1889 Posts


So basically you stuck your OWN fermentation?

Warm it back up and give it a gently swirl. And the yeast hopefully will wake back up.
__________________
Like my snazzy new avatar? Get Sons of Zymurgy swag, here, and brew with the best.

Revvy's one of the cool reverends. He has a Harley and a t-shirt that says on the back "If you can read this, the bitch was Raptured. - Madman

I gotta tell ya, just between us girls, that Revvy is HOT. Very tall, gorgeous grey hair and a terrific smile. He's very good looking in person, with a charismatic personality... he drives like a ****ing maniac! - YooperBrew

 
Reply With Quote
Old 09-22-2010, 02:56 PM   #5
AlchemyBrewing
Recipes 
 
Apr 2010
Denver
Posts: 92

Yeah I guess... if that really was the problem. I guess I am confused by my previous understanding about fermentation time and what may be a new theory. None of the books I have (really old I guess) talk about a fermentation going more than a week or so. When activity slows way down and the Kreusen drops you are done. Is this completely a wrong theory now?
__________________
I AM ......LIFTING BOY!

 
Reply With Quote
Old 09-22-2010, 03:05 PM   #6
Revvy
Post Hoc Ergo Propter Hoc
HBT_LIFETIMESUPPORTER.png
 
Revvy's Avatar
Recipes 
 
Dec 2007
"Detroitish" Michigan
Posts: 40,925
Liked 3201 Times on 1889 Posts


Quote:
Originally Posted by AlchemyBrewing View Post
Yeah I guess... if that really was the problem. I guess I am confused by my previous understanding about fermentation time and what may be a new theory. None of the books I have (really old I guess) talk about a fermentation going more than a week or so. When activity slows way down and the Kreusen drops you are done. Is this completely a wrong theory now?
You really only know your fermentation is done, or anything else really with a hydrometer. Or by giving the beer plenty of time on the yeast.

Fermentation is just the tip of the iceburgh of what the yeast do, they are very fastiduous creatures and if given time, will clean up the byproducts of their fermentation, the stuff that leads to off flavors.

Krausems, calendars and airlock bubbling are very inaacurate guides to what a beer is doing. The only diagnostic tool is a hydro reading.

I've had krausen fall and the beer still not near terminal gravity (verified by a hydrometer) as well as having a krausen staying up for over three weeks despite fermentation being done (as verified by a hydrometer.)

Papazian's book is over 30 years old, and very little has been revised in subsequent editions. Palmers is getting near 10 years old and even there he as revised stuff from the online edition.

Information does change. Now most of us leave our beer in primary for 3-4 weeks to give the yeast plenty of time NOT to get stuck, and to clean up after itself.

THIS is where the most state of the art info is....and most of it has been discussed and repeated over and over so it's not hard to find.

You can read about it here http://www.homebrewtalk.com/f163/sec...ghlight=palmer

Bottom line, patience in brewing is the "new black."
__________________
Like my snazzy new avatar? Get Sons of Zymurgy swag, here, and brew with the best.

Revvy's one of the cool reverends. He has a Harley and a t-shirt that says on the back "If you can read this, the bitch was Raptured. - Madman

I gotta tell ya, just between us girls, that Revvy is HOT. Very tall, gorgeous grey hair and a terrific smile. He's very good looking in person, with a charismatic personality... he drives like a ****ing maniac! - YooperBrew

 
Reply With Quote
Old 09-22-2010, 03:09 PM   #7
AlchemyBrewing
Recipes 
 
Apr 2010
Denver
Posts: 92

Thanks man. Do you just use a wine thief to get the sample for the hydro? I really appreciate this.
__________________
I AM ......LIFTING BOY!

 
Reply With Quote
Old 09-22-2010, 03:13 PM   #8
Revvy
Post Hoc Ergo Propter Hoc
HBT_LIFETIMESUPPORTER.png
 
Revvy's Avatar
Recipes 
 
Dec 2007
"Detroitish" Michigan
Posts: 40,925
Liked 3201 Times on 1889 Posts


You can but I prefer a turkey baster and a hydrometer test jar.
__________________
Like my snazzy new avatar? Get Sons of Zymurgy swag, here, and brew with the best.

Revvy's one of the cool reverends. He has a Harley and a t-shirt that says on the back "If you can read this, the bitch was Raptured. - Madman

I gotta tell ya, just between us girls, that Revvy is HOT. Very tall, gorgeous grey hair and a terrific smile. He's very good looking in person, with a charismatic personality... he drives like a ****ing maniac! - YooperBrew

 
Reply With Quote
Old 09-22-2010, 03:15 PM   #9
AlchemyBrewing
Recipes 
 
Apr 2010
Denver
Posts: 92

I am using a 6.5gal glass carboy and don't think a turkey baster will get down far enough to pull a sample. What are you fermenting in?
__________________
I AM ......LIFTING BOY!

 
Reply With Quote
Old 09-22-2010, 03:16 PM   #10
Revvy
Post Hoc Ergo Propter Hoc
HBT_LIFETIMESUPPORTER.png
 
Revvy's Avatar
Recipes 
 
Dec 2007
"Detroitish" Michigan
Posts: 40,925
Liked 3201 Times on 1889 Posts


Quote:
Originally Posted by AlchemyBrewing View Post
I am using a 6.5gal glass carboy and don't think a turkey baster will get down far enough to pull a sample. What are you fermenting in?
Mine works with buckets and carboys.
__________________
Like my snazzy new avatar? Get Sons of Zymurgy swag, here, and brew with the best.

Revvy's one of the cool reverends. He has a Harley and a t-shirt that says on the back "If you can read this, the bitch was Raptured. - Madman

I gotta tell ya, just between us girls, that Revvy is HOT. Very tall, gorgeous grey hair and a terrific smile. He's very good looking in person, with a charismatic personality... he drives like a ****ing maniac! - YooperBrew

 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Stalled Fermentation thisisxxmyIPA Fermentation & Yeast 2 09-12-2010 05:21 PM
Fermentation stalled, or not? nuclearnova Fermentation & Yeast 8 08-02-2010 03:32 AM
Uh oh.... first stalled fermentation. brutus09 Fermentation & Yeast 18 04-14-2010 06:52 PM
Stalled fermentation? lyacovett Fermentation & Yeast 13 03-31-2010 05:36 PM
Stalled fermentation Auspice Fermentation & Yeast 6 12-12-2009 03:42 AM


Forum Jump