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General Category => General Homebrew Discussion => Topic started by: brulosopher on July 13, 2015, 12:59:35 PM

Title: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: brulosopher on July 13, 2015, 12:59:35 PM
Contributor Greg compared oxygenating with pure O2 vs shaking in a split batch of the same wort!

http://brulosophy.com/2015/07/13/wort-aeration-pt-2-shaken-vs-pure-oxygen-exbeeriment-results/
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: beersk on July 13, 2015, 01:46:48 PM
I think the only thing that makes this experiment slightly falsified is the fact that dry yeast was used. Supposedly, it doesn't really need aeration at all, so any amount, shaken or pure O2, wouldn't have made a difference. I'd like to see it done on a lager.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: Stevie on July 13, 2015, 02:08:58 PM

I think the only thing that makes this experiment slightly falsified is the fact that dry yeast was used. Supposedly, it doesn't really need aeration at all, so any amount, shaken or pure O2, wouldn't have made a difference. I'd like to see it done on a lager.
Not falsified. Falsified implies it was rigged. Best term here is flawed.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: beersk on July 13, 2015, 02:42:51 PM

I think the only thing that makes this experiment slightly falsified is the fact that dry yeast was used. Supposedly, it doesn't really need aeration at all, so any amount, shaken or pure O2, wouldn't have made a difference. I'd like to see it done on a lager.
Not falsified. Falsified implies it was rigged. Best term here is flawed.
Good point. Poor choice of words on my part.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: brulosopher on July 13, 2015, 02:50:09 PM

I think the only thing that makes this experiment slightly falsified is the fact that dry yeast was used. Supposedly, it doesn't really need aeration at all, so any amount, shaken or pure O2, wouldn't have made a difference. I'd like to see it done on a lager.
I don't disagree and we definitely plan to redo it with liquid yeast in a higher OG wort. Still, had we used a liquid starter, there'd be a contingent saying we should have used dry. I've come to expect and appreciate it :)
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: Joe Sr. on July 13, 2015, 03:58:56 PM
I think the only thing that makes this experiment slightly falsified is the fact that dry yeast was used. Supposedly, it doesn't really need aeration at all, so any amount, shaken or pure O2, wouldn't have made a difference. I'd like to see it done on a lager.

That's interesting.  I don't think I've ever heard that you don't need to aerate if you're using dry yeast.

I certainly wouldn't skip it.  Or, more correctly, I never have.  But I also haven't used dry yeast much recently.  Regardless, dry yeast or not, I'm aerating.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: johnnyb on July 13, 2015, 04:02:48 PM
I think the only thing that makes this experiment slightly falsified is the fact that dry yeast was used. Supposedly, it doesn't really need aeration at all, so any amount, shaken or pure O2, wouldn't have made a difference. I'd like to see it done on a lager.

That's interesting.  I don't think I've ever heard that you don't need to aerate if you're using dry yeast.

I certainly wouldn't skip it.  Or, more correctly, I never have.  But I also haven't used dry yeast much recently.  Regardless, dry yeast or not, I'm aerating.


I've read in many places that you don't need to aerate it due to the process of how the yeast is produced. But aerating it doesn't harm it.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: rabeb25 on July 13, 2015, 04:04:01 PM
Mid to high gravity lager with liquid yeast...then we'll talk  :P
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: denny on July 13, 2015, 04:05:25 PM
I think the only thing that makes this experiment slightly falsified is the fact that dry yeast was used. Supposedly, it doesn't really need aeration at all, so any amount, shaken or pure O2, wouldn't have made a difference. I'd like to see it done on a lager.

That's interesting.  I don't think I've ever heard that you don't need to aerate if you're using dry yeast.

I certainly wouldn't skip it.  Or, more correctly, I never have.  But I also haven't used dry yeast much recently.  Regardless, dry yeast or not, I'm aerating.

I never aerate when using dry yeast.  Since the purpose of aeration is to promote cell division and growth and dry yeast has more than enough cells already, it just isn't necessary.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: denny on July 13, 2015, 04:06:18 PM
I've read in many places that you don't need to aerate it due to the process of how the yeast is produced. But aerating it doesn't harm it.

It's actually due to the cell count.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: Joe Sr. on July 13, 2015, 04:07:44 PM
I never aerate when using dry yeast.  Since the purpose of aeration is to promote cell division and growth and dry yeast has more than enough cells already, it just isn't necessary.

News to me...  I guess you're never too old, and all that.

No starter, sure.  No aeration?  Never knew that.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: denny on July 13, 2015, 04:08:26 PM
I never aerate when using dry yeast.  Since the purpose of aeration is to promote cell division and growth and dry yeast has more than enough cells already, it just isn't necessary.

News to me...  I guess you're never too old, and all that.

No starter, sure.  No aeration?  Never knew that.

It won't hurt, but it's not needed.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: dmtaylor on July 13, 2015, 04:13:02 PM
Humble suggestion: Maybe a panel of online homebrewing experts should be given an opportunity to challenge the design / test plan of each exBEERiment before it is run to assure more meaningful results.

While I do aerate my dry yeast pitched beers, I don't sweat it as much as I would with liquid yeast.

On the other hand, hindsight of the backseat passenger is always 20/40.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: johnnyb on July 13, 2015, 04:19:35 PM
I've read in many places that you don't need to aerate it due to the process of how the yeast is produced. But aerating it doesn't harm it.

It's actually due to the cell count.

As far as I've read, there are not enough cells in the dry yeast packs. But the process of how the dry yeast is manufactured is such that the cells can split several times without any additional oxygen in the wort.

Here is some info from Danstar:

Quote
Lallemand packs the maximum amount of lipids into the cell wall that is possible during the aerobic production of the yeast at the factory. When you inoculate this yeast into a starter or into the mash, the yeast can double about three time before it runs out of lipids and the growth will stop. There is about 5% lipids in the dry yeast.

In a very general view:

At each doubling it will split the lipids with out making more lipids (no O2). The first split leaves 2.5% for each daughter cell. The second split leaves 1.25% for each daughter cell. The next split leaves 0.63%. This is the low level that stops yeast multiplication. Unless you add O2 the reproduction will stop.

When you produce 3-5% alcohol beer this is no problem. It is when you produce higher alcohol beer or inoculate at a lower rate, that you need to add O2 to produce more yeast and for alcohol tolerance near the end of fermentation. You definitely need added O2 when you reuse the yeast for the next inoculum.


http://www.danstaryeast.com/articles/aeration-and-starter-versus-wort
Title: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: brulosopher on July 13, 2015, 08:48:58 PM
Humble suggestion: Maybe a panel of online homebrewing experts should be given an opportunity to challenge the design / test plan of each exBEERiment before it is run to assure more meaningful results.
Nah. This is homebrewing, not lab science. And we're not making statements of fact, just reporting our findings. I've never used O2 and likely never will, but I'll keep aerating like usual.

I'm not even sure what qualifies someone as a "homebrewing expert."
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: klickitat jim on July 13, 2015, 09:49:11 PM
Humble suggestion: Maybe a panel of online homebrewing experts should be given an opportunity to challenge the design / test plan of each exBEERiment before it is run to assure more meaningful results.
Nah. This is homebrewing, not lab science. And we're not making statements of fact, just reporting our findings. I've never used O2 and likely never will, but I'll keep aerating like usual.

I'm not even sure what qualifies someone as a "homebrewing expert."
Oh my gosh! Perfect topic for the next xbrmt. What makes a homebrew expert!
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: Joe Sr. on July 13, 2015, 10:07:45 PM
Self-proclamation, combined with some form of anointing.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: a10t2 on July 13, 2015, 10:18:54 PM
I'm not even sure what qualifies someone as a "homebrewing expert."

The Lady of the Lake, her bosom clad in shimmering ceamite, held aloft Excalibur, signifying by divine providence that I, Arthur, was to be King of the Britons. home brewers.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: Joe Sr. on July 13, 2015, 10:20:21 PM
I'm not even sure what qualifies someone as a "homebrewing expert."

The Lady of the Lake, her bosom clad in shimmering ceamite, held aloft Excalibur, signifying by divine providence that I, Arthur, was to be King of the Britons. home brewers.

Just because some watery tart lobbed a scimitar at you...
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: HoosierBrew on July 13, 2015, 10:20:41 PM
 ;D  Fantastic. Hard to top that one.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: dmtaylor on July 14, 2015, 12:27:44 AM
Heh heh.  Just so ya'll know, I was only about 25% serious.  Anyway, if pressed I might have to recommend Marshall as a "homebrewing expert".  And then there's Denny.  I myself come in a distant 100-somethingeth place.  ;)
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: Stevie on July 14, 2015, 12:53:32 AM

Heh heh.  Just so ya'll know, I was only about 25% serious.  Anyway, if pressed I might have to recommend Marshall as a "homebrewing expert".  And then there's Denny.  I myself come in a distant 100-somethingeth place.  ;)
100-somethingeth out of a few million is pretty good. Reminds me of the time I ranked 500 in the world on an angry birds level. That was a good 10 minutes.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: toby on July 14, 2015, 03:15:50 PM
I'm not even sure what qualifies someone as a "homebrewing expert."
Strange women lying in ponds distributing mash paddles.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: brewinhard on July 14, 2015, 03:17:59 PM
I'm not even sure what qualifies someone as a "homebrewing expert."
Strange women lying in ponds distributing mash paddles.

Okay, now you are getting me all worked up....
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: brulosopher on July 14, 2015, 10:13:47 PM

I'm not even sure what qualifies someone as a "homebrewing expert."
Strange women lying in ponds distributing mash paddles.
That'll work!
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: JT on July 14, 2015, 11:18:32 PM

I'm not even sure what qualifies someone as a "homebrewing expert."
Strange women lying in ponds distributing mash paddles.
That'll work!
But it's no basis for a system of government!  I must have seen this movie a hundred times in my late teens. 

Sent from my SCH-I545 using Tapatalk

Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: klickitat jim on July 15, 2015, 12:38:06 AM
So an expert is determined to be such only by the consent of the people?
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: Joe Sr. on July 15, 2015, 02:48:58 AM
So an expert is determined to be such only by the consent of the people?

Certainly not by farcical aquatic ceremonies.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: klickitat jim on July 15, 2015, 05:13:19 AM
All kidding aside, it's commonly known that one who refers to himself in the third person is the expert.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: leejoreilly on July 15, 2015, 12:41:42 PM
So an expert is determined to be such only by the consent of the people?

Certainly not by farcical aquatic ceremonies.

Help! Help! I'm being repressed!
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: toby on July 15, 2015, 01:26:48 PM
All kidding aside, it's commonly known that one who refers to himself in the third person is the expert.
Toby does not agree with this criteria.
Help! Help! I'm being repressed!
Now we see the violence inherent in the system!
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: Beerbecue on July 17, 2015, 02:38:08 AM
And the dichotomy of repression and obsession.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: S. cerevisiae on July 20, 2015, 09:07:54 PM
It's actually due to the cell count.

Actually, it's due to how dry yeast is propagated.  It takes approximately 3.8 trillion yeast cells to reach saturation (a.k.a. maximum cell density) in a 19L (5-gallon) batch; therefore, the difference between 100, 200, or even 400 billion cells is in the noise.  What matters is yeast health, and dry yeast cells are is healthier after rehydration than liquid yeast cells that are propagated the way that most home brewers propagate yeast.


Dry yeast is propagated aerobically below the Crabtree threshold in a bioreactor (propagating below the Crabtree threshold results in the carbon source being consumed via the respirative metabolic pathway).  Aerobic propagation produces yeast cells with fully-charged ergosterol and unsaturated fatty acid (UFA) reserves. The reason why we add O2 to a batch of wort is so that the cells that have been pitched can rebuild their ergosterol and UFA reserves.  Ergosterol and UFAs make yeast cell membranes more pliable, which, in turn, makes it easier for yeast cells to pass nutrients and waste products through the cell walls.  Dry yeast cells can skip this step.


Liquid yeast is propagated above the Crabtree threshold; therefore, all reproduction is fermentative.  Only the initial mother cells have fully-charged ergosterol and UFA reserves in fermentative reproduction. These mother cells share their ergosterol and UFA reserves with their daughters during each budding event.  The reason why we pitch at high krausen instead of allowing a starter to ferment out is because all replication after high krausen has been reached is for replacement only, which means that we are wasting ergosterol and UFA reserves.  In essence, the health of a culture decreases as a fermentation proceeds towards quiescence.

Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: denny on July 20, 2015, 09:09:55 PM
Thanks, Mark.
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: S. cerevisiae on July 21, 2015, 12:38:37 AM
For those who are interested in understanding how the Crabtree affects Saccharomyces genus yeast strains, The link below points to an interesting paper that I recently read that compares how Saccharomyces (Crabtree positive) and Kluyveromyces (Crabtree negative) yeast strains respond to changes in glucose concentration in a chemostat. A chemostat is a type of bioreactor.   It's the type of bioreactor that is used to propagate dry yeast.  It's called a chemostat because the bioreactor can maintain the solution at a steady (chemically static) state by continuously adding medium and O2 while continuously drawing off yeast.  That's how Lallemand and Fermentis can propagate below the Crabtree threshold.

www.researchgate.net/profile/Gianni_Liti/publication/41322073_Physiological_responses_of_Crabtree_positive_and_Crabtree_negative_yeasts_to_glucose_upshifts_in_a_chemostat/links/00b7d52697ccb18184000000.pdf?disableCoverPage=true
Title: Re: Wort Aeration - Pt. 2: Pure O2 vs. Shaken | exBEERiment Results!
Post by: dunngood on July 21, 2015, 01:38:26 AM
No expert here but this is the way I understand it. When liquid yeast is first pitched they need  oxygen to build sterols and other needs for full formation.
The Danstar report says they add enough Lipids to not need this phase and pretty much go to the formation phase where both liquid and dry yeast are wanted to expand 2 to 3 times to finish.
Unless you are brewing a high gravity beer there is enough cell count in a dry pack.