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General Category => Yeast and Fermentation => Topic started by: PharmBrewer on September 11, 2016, 11:16:12 PM

Title: Best Way to Aerate Wort
Post by: PharmBrewer on September 11, 2016, 11:16:12 PM
See Olive Oil Information here:

https://havencrest-microbrewery.blogspot.com/2016/09/olive-oil-vs-aerating-wort.html
Title: Re: Best Way to Aerate Wort
Post by: Stevie on September 11, 2016, 11:58:39 PM
Dude, stop posting links to your blog without contributing in other threads.

This technique is also bunk that was not meant for beer production and has been disproven many times over. Grady himself had said it was misinterpreted by the Homebrew community.

Good job summarizing an 8 year old article. What's next, hops help keep bacteria at bay?
Title: Re: Best Way to Aerate Wort
Post by: BUZZSAW52 on September 11, 2016, 11:58:50 PM
Significantly higher esters? No thanks.  I will use my oxygenation kit. Using olive oil will also increase the calorie count and our beers don't need any help in that department.


Sent from my iPhone using Tapatalk
Title: Re: Best Way to Aerate Wort
Post by: BUZZSAW52 on September 11, 2016, 11:59:26 PM
Dude, stop posting links to your blog without contributing in other threads.

This technique is also bunk that was not meant for beer production and has been disproven many times over. Grady himself had said it was misinterpreted by the Homebrew community.

Good job summarizing an 8 year old article. What's next, hops help keep bacteria at bay?
Hahahahahaha


Sent from my iPhone using Tapatalk
Title: Re: Best Way to Aerate Wort
Post by: HoosierBrew on September 12, 2016, 12:01:07 AM
Dude, stop posting links to your blog without contributing in other threads.

This technique is also bunk that was not meant for beer production and has been disproven many times over. Grady himself had said it was misinterpreted by the Homebrew community.

Good job summarizing an 8 year old article. What's next, hops help keep bacteria at bay?



Nice work, you beat me to it. Next thing you know, we'll hear that we don't need to do a secondary.
Title: Re: Best Way to Aerate Wort
Post by: natebrews on September 12, 2016, 12:20:48 AM
Nice work, you beat me to it. Next thing you know, we'll hear that we don't need to do a secondary.

What next, are you going to tell me I should stop using Netscape...
Title: Re: Best Way to Aerate Wort
Post by: 69franx on September 12, 2016, 01:42:55 AM
Nice work, you beat me to it. Next thing you know, we'll hear that we don't need to do a secondary.

What next, are you going to tell me I should stop using Netscape...
Classic!
Title: Re: Best Way to Aerate Wort
Post by: Stevie on September 12, 2016, 02:06:00 AM
Nice work, you beat me to it. Next thing you know, we'll hear that we don't need to do a secondary.

What next, are you going to tell me I should stop using Netscape...
I have a blog post that can help you make the switch. I'd give you a link, but I'm busy migrating it from Angelfire to Geocities.
Title: Re: Best Way to Aerate Wort
Post by: kramerog on September 12, 2016, 02:23:46 PM
I rack with aeration and then create a vortex in the carboy, so called shaking.
Title: Re: Best Way to Aerate Wort
Post by: reverseapachemaster on September 12, 2016, 02:36:20 PM
I'm on 14.4k. Can somebody tell me if this hyperlink is worth clicking?
Title: Re: Best Way to Aerate Wort
Post by: denny on September 12, 2016, 03:25:22 PM
See Olive Oil Information here:

https://havencrest-microbrewery.blogspot.com/2016/09/olive-oil-vs-aerating-wort.html

Olive oiul had been completely debunked as an "aeration" method.
Title: Re: Best Way to Aerate Wort
Post by: zwiller on September 12, 2016, 04:11:27 PM
Sorry it took so long to vote I had to wait for a new AOL disk. 
Title: Re: Best Way to Aerate Wort
Post by: HoosierBrew on September 12, 2016, 04:39:15 PM
Voted via carrier pigeon but it doesn't look like he's shown up yet - must be a headwind.  So I checked one of the choices and submitted just to be safe.
Title: Re: Best Way to Aerate Wort
Post by: Steve Ruch on September 12, 2016, 09:38:14 PM
Isn't aeration not all that necessary if you pitch enough healthy yeast?
Title: Re: Best Way to Aerate Wort
Post by: zwiller on September 13, 2016, 02:31:12 PM
Isn't aeration not all that necessary if you pitch enough healthy yeast?

That's my take...  Also a non-issue with dry yeast. 
Title: Re: Best Way to Aerate Wort
Post by: denny on September 13, 2016, 03:32:46 PM
Isn't aeration not all that necessary if you pitch enough healthy yeast?

Indeed.
Title: Re: Best Way to Aerate Wort
Post by: Lazy Ant Brewing on September 13, 2016, 06:31:25 PM
Is it correct that dry yeast needs no aeration at all?

Thanks in advance for your replies.
Title: Re: Best Way to Aerate Wort
Post by: Stevie on September 13, 2016, 06:43:25 PM
Is it correct that dry yeast needs no aeration at all?

Thanks in advance for your replies.
That's what some say. Basically they have everything they need to get started in the dry form. Liquid yeast relies on oxygen to synthesize sterols, or some sciencey answer.
Title: Re: Best Way to Aerate Wort
Post by: denny on September 13, 2016, 07:01:32 PM
Is it correct that dry yeast needs no aeration at all?

Thanks in advance for your replies.

Yes, because the cell count of dry yeast is so high, most of the time there is no need for cell growth and therefore no need for aeration. 
Title: Re: Best Way to Aerate Wort
Post by: neddles on September 13, 2016, 09:00:16 PM
If pitching the "proper" amount of yeast there is no need for growth and therefor no need for any dissolved O2 in the wort…. should I be expecting to find the same number of cells at the bottom of my fermentor after fermentation that I pitched before fermentation? Or what am I missing here?
Title: Re: Best Way to Aerate Wort
Post by: denny on September 14, 2016, 01:06:40 AM
If pitching the "proper" amount of yeast there is no need for growth and therefor no need for any dissolved O2 in the wort…. should I be expecting to find the same number of cells at the bottom of my fermentor after fermentation that I pitched before fermentation? Or what am I missing here?

Hmmm...good question.  I don't really know.  All I can say is that I successfully repitch yeast from a fermentation done like that.
Title: Re: Best Way to Aerate Wort
Post by: neddles on September 14, 2016, 02:53:43 AM
If pitching the "proper" amount of yeast there is no need for growth and therefor no need for any dissolved O2 in the wort…. should I be expecting to find the same number of cells at the bottom of my fermentor after fermentation that I pitched before fermentation? Or what am I missing here?

Hmmm...good question.  I don't really know.  All I can say is that I successfully repitch yeast from a fermentation done like that.

And your experience doing that is most valuable and applicable. But the idea that I will get zero increase in the number of yeast cells I pitched from a ferment of 5.5 gallons is pretty hard to believe.
Title: Re: Best Way to Aerate Wort
Post by: stevecrawshaw on September 14, 2016, 01:19:12 PM
My method's not on that list, so FWIW, this is it.

I ferment in a plastic jerrycan from no-chill and have around 15L wort in a 23L jerrycan, so headspace. When it's cool I squirt pure O2 into the headspace after pitching and shake like it owes me money. After 18 - 24 hours fermentation I do the same again following the guidance in "Yeast" which is that this is the period at which oxygen is most beneficial for the synthesis of sterols. This practice also aligns with the principles of the shaken not stirred starter in that the availability of oxygen to wort is maximised in the oxygen rich foam from shaking.

As others have said, this may not be necessary, but my fermentations are always healthy and never any off flavours from fermenting.
cheers
steve
Title: Re: Best Way to Aerate Wort
Post by: narcout on September 14, 2016, 08:19:30 PM
Is it correct that dry yeast needs no aeration at all?

Thanks in advance for your replies.

http://www.lallemandyeast.com/articles/crabtree-effect-and-overflow-metabolism

"When the wort has more than >0.2% sugar, the function of the O2 is to assist the yeast in producing lipids. The lipids in the cell wall act as a growth factor by keeping the cell wall fluid, allowing buds to form. The production of these lipids require trace amounts of oxygen to move the squalene to the lipid stage. With out O2 the mother cell cannot produce any lipids and must shares her lipids with her daughter cell. This can occur for about 3 - 4 cycles before the cell wall becomes leathery and will not allow a new bud to form. Active Dry Beer Yeast initially contain enough lipids in their cell wall for 3 - 4 growth cycles. This is enough to complete most beer fermentations."
Title: Re: Best Way to Aerate Wort
Post by: Joe Sr. on September 14, 2016, 08:33:04 PM
If pitching the "proper" amount of yeast there is no need for growth and therefor no need for any dissolved O2 in the wort…. should I be expecting to find the same number of cells at the bottom of my fermentor after fermentation that I pitched before fermentation? Or what am I missing here?

Hmmm...good question.  I don't really know.  All I can say is that I successfully repitch yeast from a fermentation done like that.

And your experience doing that is most valuable and applicable. But the idea that I will get zero increase in the number of yeast cells I pitched from a ferment of 5.5 gallons is pretty hard to believe.

If there's enough cells in a dry yeast pack such that there is no cell growth, you could never have an overpitch by re-using a yeast cake, right?  Because the yeast cake would be the same number of cells as a dry yeast pack.  Maybe I'm confused.  I don't think it's possible that there's no growth.
Title: Re: Best Way to Aerate Wort
Post by: narcout on September 15, 2016, 05:48:21 PM
If there's enough cells in a dry yeast pack such that there is no cell growth, you could never have an overpitch by re-using a yeast cake, right?

If you pitch a single packet of dry yeast into 5 gallons of wort, there will be several replication periods.

If you assume maximum cell density of 200 billion cells per liter, a 5 gallon batch size, and that a dry yeast packet contains 200 billion cells (I don't know how many cells a dry yeast packet actually contains), you are looking at approximately 4.2 replication periods.  If you assume there are 400 billion cells in a packet, you are looking at approximately 3.2 replication periods.

S.C. laid out the math here:  https://www.experimentalbrew.com/blogs/saccharomyces/yeast-cultures-are-nuclear-weapons

I suppose you could pitch enough yeast so that there was little or no cell growth, but I believe it would negatively impact flavor (that would be an interesting experiment).
Title: Re: Best Way to Aerate Wort
Post by: Joe Sr. on September 15, 2016, 06:46:07 PM
If you pitch a single packet of dry yeast into 5 gallons of wort, there will be several replication periods.

because the cell count of dry yeast is so high, most of the time there is no need for cell growth and therefore no need for aeration. 

Assuming growth=replication, Denny's statement seems incorrect.  Hence my extrapolation that if this is correct, you couldn't overpitch using a yeast cake.  Except that I'm certain that using a full yeast cake results in a drastic overpitch.

My understanding is that dry yeast doesn't need oxygen because it has sterol reserves already built up in whatever science-y way they go about making it.
Title: Re: Best Way to Aerate Wort
Post by: neddles on September 15, 2016, 09:46:16 PM
If you pitch a single packet of dry yeast into 5 gallons of wort, there will be several replication periods.

because the cell count of dry yeast is so high, most of the time there is no need for cell growth and therefore no need for aeration. 

Assuming growth=replication, Denny's statement seems incorrect.  Hence my extrapolation that if this is correct, you couldn't overpitch using a yeast cake.  Except that I'm certain that using a full yeast cake results in a drastic overpitch.

My understanding is that dry yeast doesn't need oxygen because it has sterol reserves already built up in whatever science-y way they go about making it.
Agree, and Denny has been saying the same thing WRT liquid yeast…paraphrasing, 'if you pitch enough healthy yeast then there will be no growth and therefor no need for dissolved O2 in the wort'.
Title: Re: Best Way to Aerate Wort
Post by: denny on September 15, 2016, 10:21:30 PM
Agree, and Denny has been saying the same thing WRT liquid yeast…paraphrasing, 'if you pitch enough healthy yeast then there will be no growth and therefor no need for dissolved O2 in the wort'.

I think it's inevitable that there will be some growth, but the need for growth is greatly reduced.
Title: Re: Best Way to Aerate Wort
Post by: brewinhard on September 15, 2016, 11:16:55 PM
Keep in mind the viability of the age of the packet you are getting.  Even with how slowly dry yeast drop-off, I can't imagine that 100% of the cells are ready to rock especially when the packet has a bit of age on it. Not all survive the rehydration stage either (whether its in wort or water). 
Title: Re: Best Way to Aerate Wort
Post by: JJeffers09 on September 17, 2016, 01:08:02 PM
I need to go make an olive oil, flour, juicy ipa...
Title: Re: Best Way to Aerate Wort
Post by: Philbrew on September 17, 2016, 04:07:10 PM
If you pitch a single packet of dry yeast into 5 gallons of wort, there will be several replication periods.

because the cell count of dry yeast is so high, most of the time there is no need for cell growth and therefore no need for aeration. 

Assuming growth=replication, Denny's statement seems incorrect.  Hence my extrapolation that if this is correct, you couldn't overpitch using a yeast cake.  Except that I'm certain that using a full yeast cake results in a drastic overpitch.

My understanding is that dry yeast doesn't need oxygen because it has sterol reserves already built up in whatever science-y way they go about making it.
Exactly.  But there is massive growth in the number of yeast cells!  4 replications (read 4 doublings) means that there will be 16 times as many cells in the yeast cake as compared to the original pitch.
What Narcout quoted from Lallemond said that there is enough lipids in dry yeast to accomplish 4 replications.  Anything more will require additional O2.
Title: Re: Best Way to Aerate Wort
Post by: denny on September 17, 2016, 04:21:31 PM
Exactly.  But there is massive growth in the number of yeast cells!  4 replications (read 4 doublings) means that there will be 16 times as many cells in the yeast cake as compared to the original pitch.
What Narcout quoted from Lallemond said that there is enough lipids in dry yeast to accomplish 4 replications.  Anything more will require additional O2.

3-4 replications is the commonly quoted target number.
Title: Re: Best Way to Aerate Wort
Post by: Saccharomyces on September 17, 2016, 04:27:49 PM
Isn't aeration not all that necessary if you pitch enough healthy yeast?

That is correct.   O2 demand is lessened if one pitches a starter at high krausen as well.
Title: Re: Best Way to Aerate Wort
Post by: denny on September 17, 2016, 04:29:35 PM
Isn't aeration not all that necessary if you pitch enough healthy yeast?

That is correct.   O2 demand is lessened if one pitches a starter at high krausen as well.

Good to see ya, Sacc!
Title: Re: Best Way to Aerate Wort
Post by: Saccharomyces on September 17, 2016, 04:48:57 PM
It is nice be back, Denny.
Title: Re: Best Way to Aerate Wort
Post by: Philbrew on September 17, 2016, 05:36:09 PM
Keep in mind the viability of the age of the packet you are getting.  Even with how slowly dry yeast drop-off, I can't imagine that 100% of the cells are ready to rock especially when the packet has a bit of age on it. Not all survive the rehydration stage either (whether its in wort or water).
Yes, that is why I think some aeration is a good idea even if you are pitching dry yeast.

In the last year and a half, I've pitched either dry yeast or slurry.

- I pump into the fermenter and I splash the stream around to create as much foam as possible if I'm pitching rehydrated dry yeast.

- If I'm pitching slurry, I get out the O2 stone.
Title: Re: Best Way to Aerate Wort
Post by: Philbrew on September 18, 2016, 01:43:36 AM
I need to go make an olive oil, flour, juicy ipa...
Good idea!  Denny (and Gary) will really drink it up and enjoy as long as you hop it with lots and lots of Fuggles.
Title: Re: Best Way to Aerate Wort
Post by: denny on September 18, 2016, 03:20:48 PM
I need to go make an olive oil, flour, juicy ipa...
Good idea!  Denny (and Gary) will really drink it up and enjoy as long as you hop it with lots and lots of Fuggles.

 ;D
Title: Re: Best Way to Aerate Wort
Post by: Backyard Bruise-master on September 19, 2016, 11:50:36 PM
I've been slowly making my way through White & Zainasheff's Yeast(y) tome; this topic comes up at page 75.
Long story short, adding enough O2 leads to a faster fermentation and improved attenuation.  8-10ppm is the target for most wort, and shaking only gets you in the high 2s.

Not saying anyone's process is wrong, especially if you're satisfied with the results, but why leave anything to chance?  A healthy pitch is just the start.  What about the rest of the race to FG?  :P
Title: Re: Best Way to Aerate Wort
Post by: Saccharomyces on September 20, 2016, 12:05:37 AM
O2 demand is strain specific.  Most of the brewing strains available to homebrewers fall into O2 classes O1 & O2.  The O2 demand for class O1 yeast strains can be met with half air saturated wort (4ppm).  The O2 demand for class O2 yeast strains can be met with air saturated wort (8ppm).  The outliers that are available to homebrewers are the Yorkshire strains, which are usually class O3/O4.  The O2 demand for these strains is so high that it cannot be met with pure O2 saturated wort (40ppm).  That is why Yorkshire breweries rouse and aerate fermenting beer with a fish tail.

Brian Kirsop's seminal paper on O2 demand: http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1974.tb03614.x/pdf
Title: Re: Best Way to Aerate Wort
Post by: brewinhard on September 20, 2016, 12:53:41 PM
The outliers that are available to homebrewers are the Yorkshire strains, which are usually class O3/O4.  The O2 demand for these strains is so high that it cannot be met with pure O2 saturated wort (40ppm).  That is why Yorkshire breweries rouse and aerate fermenting beer with a fish tail.



Can underation of these strains result in more diacetyl production?
Title: Re: Best Way to Aerate Wort
Post by: ynotbrusum on September 20, 2016, 10:11:51 PM
Sacc - I don't know what a fish tail is, but I don't think my wife will let me get one!  I second the welcome back to a great contributor here.  Nice article reference.  I will read this tonight.
Title: Re: Best Way to Aerate Wort
Post by: 69franx on September 20, 2016, 11:42:17 PM
Isn't aeration not all that necessary if you pitch enough healthy yeast?

That is correct.   O2 demand is lessened if one pitches a starter at high krausen as well.

Good to see ya, Sacc!
+1 Sacch
Title: Re: Best Way to Aerate Wort
Post by: Joe Sr. on September 21, 2016, 01:03:52 AM
Isn't aeration not all that necessary if you pitch enough healthy yeast?

That is correct.   O2 demand is lessened if one pitches a starter at high krausen as well.

Good to see ya, Sacc!
+1 Sacch

Yes.  Good to see youse.  Just kegged a bitter using 1768 at your recommendation.
Title: Re: Best Way to Aerate Wort
Post by: Phil_M on September 21, 2016, 10:51:56 AM
Sacc - I don't know what a fish tail is, but I don't think my wife will let me get one!  I second the welcome back to a great contributor here.  Nice article reference.  I will read this tonight.

You can see them on the side of the fermentation vessels in this picture:
https://commons.wikimedia.org/wiki/File:Black_Sheep_Brewery_Tour.jpg

They're basically just sprayers. Fermenting wort is pumped through them and sprayed back on top of the fermentor, re-aerating everything.

IIRC, some brewers remove yeast throughout fermentation, and basically keep the yeast multiplying throughout fermentation, as opposed to just in the beginning as we fo.
Title: Re: Best Way to Aerate Wort
Post by: hopfenundmalz on September 21, 2016, 12:48:02 PM
O2 demand is strain specific.  Most of the brewing strains available to homebrewers fall into O2 classes O1 & O2.  The O2 demand for class O1 yeast strains can be met with half air saturated wort (4ppm).  The O2 demand for class O2 yeast strains can be met with air saturated wort (8ppm).  The outliers that are available to homebrewers are the Yorkshire strains, which are usually class O3/O4.  The O2 demand for these strains is so high that it cannot be met with pure O2 saturated wort (40ppm).  That is why Yorkshire breweries rouse and aerate fermenting beer with a fish tail.

Brian Kirsop's seminal paper on O2 demand: http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1974.tb03614.x/pdf
Great to have you back here educating us. Thanks for the paper link.
Title: Re: Best Way to Aerate Wort
Post by: kramerog on September 21, 2016, 03:31:43 PM

Brian Kirsop's seminal paper on O2 demand: http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1974.tb03614.x/pdf

Very interesting paper.  On a sidenote it says that olive oil doesn't work as a replacement for oxygen, but sterols do.
Title: Re: Best Way to Aerate Wort
Post by: Steve Ruch on September 21, 2016, 09:34:46 PM

Brian Kirsop's seminal paper on O2 demand: http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1974.tb03614.x/pdf

Very interesting paper.  On a sidenote it says that olive oil doesn't work as a replacement for oxygen, but sterols do.

I know where olive oil is, but which aisle in the grocery store has the sterols?  ;)