Coldbreak Brewing HERMS Giveaway!

HomeBrewSupply AMCYL Brew Kettle Giveaway!


Home Brew Forums > Home Brewing Beer > Beginners Beer Brewing Forum > Can you over ferment?
Closed Thread
 
Thread Tools
Old 04-06-2011, 09:54 PM   #31
beerkrump
Feedback Score: 0 reviews
Recipes 
 
Join Date: Mar 2009
Location: Triune, TN
Posts: 2,124
Liked 13 Times on 13 Posts

Default

Quote:
Originally Posted by Indyking View Post
Trust me.
Over all those authors and their "anecdotal" work? Nah.

It's obvious that you have it stuck in your head that yeast requires sugar to do anything. Just be aware that there are processes that move compounds in and out of the yeast cell with little or no loss of energy. Some of these are slow to finish.

Much of this "clean up" is done in a transitional period between the fermentation phase and the stationary phase. None of this is like a light switch, one second yeast is munching sugars and the next, boom, dormancy.

Also, from the article I referenced...

Table I
Diacetyl formation in three yeast strains.
Day_________Diacetyl Level (mg/L)
_____W-206____W-34/70____W-308
1_____.18_______.15________.18
3_____.25_______.20________ .48
5_____.23 _______.18________ .92
7_____.18 _______.14 ________.75
9_____.14 _______.09 ________.65

As we can see, the diacetyl level is dropping from day 7 to day 9. This is occurring after active fermentation has stopped.

You asked for documentation from a brewing scientist. I found you some, but you refuse to accept it.



Reason: I copied a table and all the blanks need to be replaced with _.
beerkrump is offline
 
Old 04-06-2011, 09:55 PM   #32
ChshreCat
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
ChshreCat's Avatar
Recipes 
 
Join Date: Aug 2008
Location: Camano Island, Washington
Posts: 11,576
Liked 532 Times on 426 Posts
Likes Given: 21

Default

Just because you don't understand it, that doesn't make it not true.


ChshreCat is offline
 
Old 04-06-2011, 10:06 PM   #33
o4_srt
Feedback Score: 0 reviews
Recipes 
 
Join Date: Jan 2010
Location: Lancaster, PA
Posts: 1,330
Liked 14 Times on 14 Posts

Default

So the taste of green beer is simply because of yeast still in suspension????

Seems kinda hard to believe, as green beer doesn't taste very yeasty
__________________
Facebite Brewing

Conditioning: Muddy Paw Nut Brown Ale, Jump The Fence Independence Cream Ale
o4_srt is offline
 
Old 04-06-2011, 10:17 PM   #34
ayoungrad
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2010
Location: Tampa, FL
Posts: 1,102
Liked 10 Times on 10 Posts
Likes Given: 1

Default

Indyking, the problem I had with your original post is that you said:

It's the possible myth that yeasts clean up after themselves and improve the quality of the beer with prolonged primaries.

I think you either stated yourself incorrectly or misunderstand what people have previously said.

A good number of people on here suggest not transferring to secondary and instead just leaving the beer in the primary fermenter. No one has suggested that a "prolonged primary" exists. I don't even know what a prolonged primary is. Some people have simply suggested to leave the beer in the primary fermentation chamber for longer and forgo transferring it into a secondary fermenter.

The same clean-up will occur in either chamber. Yeast will help metabolize diacetyls, sulfur compounds and volatile fatty acids. They need sugar but there is always some small amount left even after primary fermentation is "complete". This happens if the beer is left in the primary fermentation chamber or if it goes into a secondary fementation chamber. Most of the yeast go dormant when concentrations fall to very low levels but not 100% of them. Some people just feel that the risks of oxidation (or infection) involved in transferring to a secondary fermentation vessel are greater than any theoretical gain in clarity.

Again, I don't know if the issue here has been a misunderstanding or misinterpretation but there is no such thing as "prolonged primary fermentation" and I have not seen such a concept suggested on this site.
ayoungrad is offline
 
Old 04-06-2011, 10:34 PM   #35
ayoungrad
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2010
Location: Tampa, FL
Posts: 1,102
Liked 10 Times on 10 Posts
Likes Given: 1

Default

Sorry but one other thought here.

Using bold letters for something that clearly flies in the face of popular opinion (be it correct or incorrect opinion) is always going to result in people responding from all directions.

And saying "don't fight me on this" or "trust me" is only more of the same.

I don't know Indyking's background. But I do know that even if it involves a PhD in biochemistry, it is certainly not the only PhD in biochemistry in the world and likely not the only one on this site either. There are scientists, engineers and doctors all over this site.

If you bring up an new thought or idea, why not phrase it as such and have a discussion. Even you admit to feeling a "fight" response from the board on this thread. And it is because how your thought was stated.

Is it everyone else with the issue or is it you?
ayoungrad is offline
 
Old 04-06-2011, 10:37 PM   #36
BrewKnurd
Formerly discnjh
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
BrewKnurd's Avatar
Recipes 
 
Join Date: Mar 2011
Location: Prairieville, LA
Posts: 2,766
Liked 243 Times on 201 Posts
Likes Given: 112

Default

Quote:
Originally Posted by ayoungrad View Post
Sorry but one other thought here.

Using bold letters for something that clearly flies in the face of popular opinion (be it correct or incorrect opinion) is always going to result in people responding from all directions.

And saying "don't fight me on this" or "trust me" is only more of the same.

I don't know Indyking's background. But I do know that even if it involves a PhD in biochemistry, it is certainly not the only PhD in biochemistry in the world and likely not the only one on this site either. There are scientists, engineers and doctors all over this site.

If you bring up an new thought or idea, why not phrase it as such and have a discussion. Even you admit to feeling a "fight" response from the board on this thread. And it is because how your thought was stated.

Is it everyone else with the issue or is it you?

BrewKnurd is offline
 
Old 04-06-2011, 11:55 PM   #37
Indyking
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2010
Location: Indy-Madison (WI)
Posts: 690
Liked 11 Times on 11 Posts
Likes Given: 8

Default

Every once in a while I see minor pieces of information here that I think it may be wrong, but I don't bother to argue because I'm either not sure or it's just not worth it. But the yeast-cleaning-up-after-fermentation-is-complete thing has gone too far unquestioned I think.

I have strong reasons to believe brewing yeast cells stop any significant metabolism after their main source of energy, sugar, is depleted. I have showed evidence, some less but other purely scientific to prove my point. I'm not a microbiologist but I do have a cell biology background and my PhD was done in a microbiology lab sharing knowledge with a majority of microbiologists, though all of them were bacteriologists.

The idea supported by many here is to not use a secondary fermentation and ferment your beer beyond that period where final SG has been reached, so the yeast can clean-up after themselves and result in a better final product. That just doesn't happen IMHO. I never actually secondary any Ale as a matter of fact and I also keep my primary way beyond after fermentation is complete because I simply believe that stretching that time allow solids, including inactive yeast, to sediment better maximizing the appearance and possibly flavor of the beer. It has nothing to do with yeasts cleaning-up anything. They can't do it without energy and after fermentation is complete, their source of energy is gone and they become dormant.

In the case of D-rest, like I said before, John Palmer himself in the latest edition of his book How to Brew states that it is important to do it in the right time before lagering, which is before fermentation is totally complete, so the yeast will have substrate available to clean up the diacetyl. A lot of people will tell that they actually do a successful D-rest after fermentation is finished. I believe that is wrong too.
Fermentation in lagers is very slow. It may have long passed the peak of fermentation where airlock activity is typically noticed, but there is still some residual fermentable sugars available for the D-rest, only it's very scarce, hence the need to increase the temperature to activate the almost dormant yeast.

Look. I'm sorry for the bold letters, OK, sometimes I just can't help it. You can believe whatever you want too. I'm not asking you to believe in what I'm saying about this, but perhaps you all will think about it whenever that perception comes across again.

Finally, I brewed an English Brown Ale about 3 weeks ago, which I have bottled half of the 5 gal batch right after fermentation was completed and will bottle the other half after resting the remaining in the primary vessel for a month. After all have been carbed, I will taste them in a blind fashion to see if I can tell them apart. Because I don't likely have the most accurate palate in the world, barely that, I'm looking for BJCP-certified folk here who is willing to degust them as well in the same fashion. I highly suspect there will be a noticeable difference between them, not because of the famous, or infamous, yeast clean-up paradigm, but for the reasons aforementioned in this post.

Cheers!
Indyking is offline
 
Old 04-07-2011, 12:22 AM   #38
BrewKnurd
Formerly discnjh
HBT_SUPPORTER.png
Feedback Score: 0 reviews
 
BrewKnurd's Avatar
Recipes 
 
Join Date: Mar 2011
Location: Prairieville, LA
Posts: 2,766
Liked 243 Times on 201 Posts
Likes Given: 112

Default

Quote:
Originally Posted by Indyking View Post
Finally, I brewed an English Brown Ale about 3 weeks ago, which I have bottled half of the 5 gal batch right after fermentation was completed and will bottle the other half after resting the remaining in the primary vessel for a month. After all have been carbed, I will taste them in a blind fashion to see if I can tell them apart. Because I don't likely have the most accurate palate in the world, barely that, I'm looking for BJCP-certified folk here who is willing to degust them as well in the same fashion. I highly suspect there will be a noticeable difference between them, not because of the famous, or infamous, yeast clean-up paradigm, but for the reasons aforementioned in this post.

Cheers!
This is not an experiment which in any way proves your theory, so I'm not sure why its relevant. All you prove is that there is a difference between a shorter primary and a longer primary, NOTHING about WHY that happens.
BrewKnurd is offline
 
Old 04-07-2011, 12:28 AM   #39
Indyking
Feedback Score: 0 reviews
Recipes 
 
Join Date: Aug 2010
Location: Indy-Madison (WI)
Posts: 690
Liked 11 Times on 11 Posts
Likes Given: 8

Default

Quote:
Originally Posted by discnjh View Post
This is not an experiment which in any way proves your theory, so I'm not sure why its relevant. All you prove is that there is a difference between a shorter primary and a longer primary, NOTHING about WHY that happens.
I never said I'm doing this experiment to prove my theory. My theory is out there for whoever is interested in a second opinion. My experiment is to prove my other hypothesis that beer benefit from long resting after fermentation is complete for other reasons that has nothing to do with yeast cells cleaning up, as already mentioned.
Indyking is offline
 
Old 04-07-2011, 12:36 AM   #40
camus
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2010
Location: flatland
Posts: 217
Likes Given: 1

Default

My beer tastes much better if it sits in the primary longer, even if I do a secondary, longer in the primary is better.

Sent from my iPhone using HB Talk


camus is offline
 
Closed Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Where to ferment? Grimster Beginners Beer Brewing Forum 3 12-30-2009 02:54 PM
hot ferment? ridd Beginners Beer Brewing Forum 7 06-20-2009 09:36 PM
Second Ferment Enhoffer-Knopfe Beginners Beer Brewing Forum 1 11-14-2008 05:01 AM
When did this ferment?!?!?! brandona33 Beginners Beer Brewing Forum 5 04-03-2008 05:45 PM
What can I ferment in? rooky Beginners Beer Brewing Forum 2 03-23-2008 05:22 PM


Forum Jump

Newest Threads

LATEST SPONSOR DEALS