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Author Topic: Using O2...  (Read 5248 times)

Offline Bel Air Brewing

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Re: Using O2...
« Reply #30 on: March 31, 2022, 02:09:09 pm »
We never employ O2 injection. And we rarely even make a starter anymore. Most of our yeast is harvested, and used very fresh. So fresh, that it explodes like a volcano when shaken, and this is how I get oxygen into the yeast prior to pitching, by vigorously shaking the bottle.

This is Diamond Lager, the best performing yeast we have used.

Offline Richard

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Re: Using O2...
« Reply #31 on: March 31, 2022, 02:37:07 pm »
I also wonder if any and all LO steps have reduced O2 that the yeast might take up when it's pitched.  IIRC, there is virtually no O2 in the wort while you're boiling and even the LO guys say that a "splashy transfer" (as it was called) is fine so maybe LO steps have no bearing on this.  I need to find a glass 1-gallon jug so I can try an SNS starter.  I know Denny says APPLE JUICE! but my stores do not carry any apple juice in glass containers.  I'll keep looking.
Grab a gallon of mayonnaise at Costco or Sam’s, eat a bunch of sandwiches, and then your problem will be solved!

Or buy a 1 gallon fermenter off Amazon like I did.

I use a 1-gallon water jug with molded-in handle. Lightweight, shatterproof, and easy to shake with the handle. Can also withstand boiling temperatures to sterilize.
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Offline Richard

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Re: Using O2...
« Reply #32 on: March 31, 2022, 02:41:13 pm »
Note that Denny is now using SNS starters. That process gives the yeast oxygen before pitching it into the beer. Is it enough oxygen? The inventor of the SNS method says yes, but I am not convinced. I think that some kind of aeration during the transfer from kettle to fermenter is still worthwhile. I have a wine-type aerator that I put on the end of my transfer hose. I no longer use oxygen except for very high gravity beers.

Are you not convinced due to your experience?
Yes. I am also skeptical that 1 liter of wort in the starter can provide adequate oxygen when the recommendation for oxygenation is to take 20 liters to saturation. SNS starters are convenient, but I see longer lag times with them than when I pitch a chilled and decanted starter with oxygen.
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Online Village Taphouse

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Re: Using O2...
« Reply #33 on: March 31, 2022, 03:01:47 pm »
Yes. I am also skeptical that 1 liter of wort in the starter can provide adequate oxygen when the recommendation for oxygenation is to take 20 liters to saturation. SNS starters are convenient, but I see longer lag times with them than when I pitch a chilled and decanted starter with oxygen.
Oh no.  Now you have me wringing my hands over the SNS method.  Sacro was so convincing on the "stir-plate starters are no good" argument but I know that I mentioned that when I make a starter in a flask using wort and O2 and a stirplate, I get very quick activity and the beers honestly come out excellent.  I am going to try the SNS method because I want to be open minded and I want to be able to say I tried both methods.  But at this moment I am actually very happy with the results I have been getting otherwise I would have been looking for something better a long time ago. 
« Last Edit: March 31, 2022, 03:05:31 pm by Village Taphouse »
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Offline chumley

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Re: Using O2...
« Reply #34 on: March 31, 2022, 03:06:13 pm »
I'm of the use O2 for some liquid yeasts, not for dry yeast, camp.

For English bitters, I add O2 before pitching, and then hit the fermenters with O2 again 12 to 18 hours again, before high krausen begins. I think it helps develop the fruity esters I like in them.

Offline denny

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Re: Using O2...
« Reply #35 on: March 31, 2022, 03:28:18 pm »
Note that Denny is now using SNS starters. That process gives the yeast oxygen before pitching it into the beer. Is it enough oxygen? The inventor of the SNS method says yes, but I am not convinced. I think that some kind of aeration during the transfer from kettle to fermenter is still worthwhile. I have a wine-type aerator that I put on the end of my transfer hose. I no longer use oxygen except for very high gravity beers.

Are you not convinced due to your experience?
Yes. I am also skeptical that 1 liter of wort in the starter can provide adequate oxygen when the recommendation for oxygenation is to take 20 liters to saturation. SNS starters are convenient, but I see longer lag times with them than when I pitch a chilled and decanted starter with oxygen.

I have not been able to correlate lag time to starter type personally.  For instance, on my last batch I pitched a SNS starter of 1450 and saw krausen within 3-4 hours.  Sometimes it takes longer, but even when it does the beer quality has not been adversely affected.
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Offline denny

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Re: Using O2...
« Reply #36 on: March 31, 2022, 03:29:38 pm »
Yes. I am also skeptical that 1 liter of wort in the starter can provide adequate oxygen when the recommendation for oxygenation is to take 20 liters to saturation. SNS starters are convenient, but I see longer lag times with them than when I pitch a chilled and decanted starter with oxygen.
Oh no.  Now you have me wringing my hands over the SNS method.  Sacro was so convincing on the "stir-plate starters are no good" argument but I know that I mentioned that when I make a starter in a flask using wort and O2 and a stirplate, I get very quick activity and the beers honestly come out excellent.  I am going to try the SNS method because I want to be open minded and I want to be able to say I tried both methods.  But at this moment I am actually very happy with the results I have been getting otherwise I would have been looking for something better a long time ago.

Ken, you'll never know until you try it.
Life begins at 60.....1.060, that is!

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Offline ynotbrusum

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Re: Using O2...
« Reply #37 on: March 31, 2022, 03:58:06 pm »
I tried just about everything mentioned above and have adopted a simple approach of using rehydrated LalleMand and no rehydration of other dry yeasts. I apply oxygen through a wine degasser on a drill for any liquid yeast (rehydrated counts as liquid for these purposes).  I have pitched tons of yeast so no yeast growth occurred on those to almost stressful in underpitching.  Like Denny,I just found what works for me and stay with it. I rarely take yeast out beyond 6 generations (I have repitched 25 times as a max without problems), so it can be done and still had good beers in that all the way through.  I just prefer what I have landed on and prescribe to the you do you idea.
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Online Village Taphouse

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Re: Using O2...
« Reply #38 on: March 31, 2022, 04:30:26 pm »
This could be a good time to mention that dry yeast has come a long way and it seems like A LOT of brewers are using dry yeast.  For me, I could be pretty happy with S-04 and BRY-97 for ales and then 34/70 or Diamond (and even S-189) for lagers.  If they could find a way to make Omega Bayern and also Omega 113 (which I believe is the same as WLP940 Mexican) in dry form... I might actually punt liquid yeast.  The vast majority of the time I brew lagers I use 2124 (which is 34/70 and Diamond), Bayern and 940.  Most of the time I brew ales it's 1056/WLP001 or something English like 1469 or maybe 1028.  If anyone hears that Bayern or 940 have been released in dry format, please post.  That would be righteous. 
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Offline lupulus

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Re: Using O2...
« Reply #39 on: March 31, 2022, 04:42:50 pm »




Note that Denny is now using SNS starters. That process gives the yeast oxygen before pitching it into the beer. Is it enough oxygen? The inventor of the SNS method says yes, but I am not convinced. I think that some kind of aeration during the transfer from kettle to fermenter is still worthwhile. I have a wine-type aerator that I put on the end of my transfer hose. I no longer use oxygen except for very high gravity beers.

Anybody that knows biochemistry and yeast (and any cell) aerobic metabolism can tell you that there won't be any significant yeast growth if you don't oxygenate at pitching.
If you have enough viable and vital cells at pitching (whatever the method used to produce the cells) to carry the fermentation, then the wort will ferment, if not, it won't ferment completely.

Yeast growth produces secondary flavor compounds, so beer from a fermentation with yeast growth will taste differently from beer produced with no yeast growth.
Better or worse is for the brewer to decide.

Is it enough oxygen?
It depends.
Is NOT enough to produce significant growth during the main fermentation.
It may be enough to produce sufficient cells in your starter depending on many factors including initial count and vitality, nutrients provided and oxygen provided.

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If by metabolism you mean respiration, then brewers yeast can't be put in the same category as "any cell". Yeast in beer wort do not use the oxygen for aerobic respiration because of the Crabtree effect. At the sugar concentration found in even weak beer wort, yeast will always use the anaerobic fermentation pathway to multiply, regardless of how much oxygen is present. Oxygenating the wort, whether via splashing or stone, does not necessarily result in more cells, it results in stronger cells that can more easily cross the finish line.

That was not my point.
Cells, including yeast, don't have the ability to store oxygen.
So, you can't give the oxygen "in advance".

The statement "yeast will always use the anaerobic fermentation pathway to multiply" is incorrect.
You can easily disprove this by weighing the yeast biomass pitched and the final yeast biomass after fermentation under different oxygenation rates.
That's why we shake or use stir plates or bioreactors.

Can yeast multiply anaerobically? Yes, of course. But you produce much more yeast with oxygenation.

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Offline lupulus

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Re: Using O2...
« Reply #40 on: March 31, 2022, 04:51:59 pm »




Note that Denny is now using SNS starters. That process gives the yeast oxygen before pitching it into the beer. Is it enough oxygen? The inventor of the SNS method says yes, but I am not convinced. I think that some kind of aeration during the transfer from kettle to fermenter is still worthwhile. I have a wine-type aerator that I put on the end of my transfer hose. I no longer use oxygen except for very high gravity beers.

Anybody that knows biochemistry and yeast (and any cell) aerobic metabolism can tell you that there won't be any significant yeast growth if you don't oxygenate at pitching.
If you have enough viable and vital cells at pitching (whatever the method used to produce the cells) to carry the fermentation, then the wort will ferment, if not, it won't ferment completely.

Yeast growth produces secondary flavor compounds, so beer from a fermentation with yeast growth will taste differently from beer produced with no yeast growth.
Better or worse is for the brewer to decide.


Is it enough oxygen?
It depends.
Is NOT enough to produce significant growth during the main fermentation.
It may be enough to produce sufficient cells in your starter depending on many factors including initial count and vitality, nutrients provided and oxygen provided.
I have mentioned and requoted your part in bold a few times and I seem to remember someone smarter than me say that yeast growth creates flavors that beer drinkers find pleasing.  The conclusion was that overpitching so that no yeast growth would occur would result in a less-pleasing beer.  I realize I am probably oversimplifying but we have knocked this around before and because of this I have restrained myself on the amount of harvested slurry I pitch on a given batch hoping that I would get some of that pleasing flavor.  Also, I have noticed a few times that the first pitch of a yeast (say, right from the starter) has produced the best beer in the group of batches made with that yeast and that first batch probably had fewer yeast cells then the subsequent batches.  I remember one specifically made with WLP940 Mexican Lager that was absolutely dynamite (first batch from the starter) and the rest of the batches were good but not as good as that one.

Graham Stewart has a nice review on the subject of yeast-created flavors.
Better or worse is the eye of the beerholder .


The Production of Secondary Metabolites with Flavour Potential during Brewing and Distilling Wort Fermentations

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Offline RC

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Re: Using O2...
« Reply #41 on: March 31, 2022, 06:41:24 pm »




Note that Denny is now using SNS starters. That process gives the yeast oxygen before pitching it into the beer. Is it enough oxygen? The inventor of the SNS method says yes, but I am not convinced. I think that some kind of aeration during the transfer from kettle to fermenter is still worthwhile. I have a wine-type aerator that I put on the end of my transfer hose. I no longer use oxygen except for very high gravity beers.

Anybody that knows biochemistry and yeast (and any cell) aerobic metabolism can tell you that there won't be any significant yeast growth if you don't oxygenate at pitching.
If you have enough viable and vital cells at pitching (whatever the method used to produce the cells) to carry the fermentation, then the wort will ferment, if not, it won't ferment completely.

Yeast growth produces secondary flavor compounds, so beer from a fermentation with yeast growth will taste differently from beer produced with no yeast growth.
Better or worse is for the brewer to decide.

Is it enough oxygen?
It depends.
Is NOT enough to produce significant growth during the main fermentation.
It may be enough to produce sufficient cells in your starter depending on many factors including initial count and vitality, nutrients provided and oxygen provided.

Sent from my SM-G981U1 using Tapatalk

If by metabolism you mean respiration, then brewers yeast can't be put in the same category as "any cell". Yeast in beer wort do not use the oxygen for aerobic respiration because of the Crabtree effect. At the sugar concentration found in even weak beer wort, yeast will always use the anaerobic fermentation pathway to multiply, regardless of how much oxygen is present. Oxygenating the wort, whether via splashing or stone, does not necessarily result in more cells, it results in stronger cells that can more easily cross the finish line.

That was not my point.
Cells, including yeast, don't have the ability to store oxygen.
So, you can't give the oxygen "in advance".

The statement "yeast will always use the anaerobic fermentation pathway to multiply" is incorrect.
You can easily disprove this by weighing the yeast biomass pitched and the final yeast biomass after fermentation under different oxygenation rates.
That's why we shake or use stir plates or bioreactors.

Can yeast multiply anaerobically? Yes, of course. But you produce much more yeast with oxygenation.

Sent from my SM-G981U1 using Tapatalk

I indeed must not have seen your point. (You are also omitting some important qualifiers in my comment.)

You implied that yeast are like any other cell in that they multiply via aerobic respiration when oxygen is present. My point was, no they don't. That's only true when the sugar concentration is below the Crabtree threshold (IIRC, <0.2% sugar concentration). Perhaps we have different understandings of the Crabtree effect.

To be honest, I don't understand most of your comment above. However, you are correct that cells do not store oxygen.

Offline HighVoltageMan!

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Re: Using O2...
« Reply #42 on: April 01, 2022, 06:01:16 am »




Note that Denny is now using SNS starters. That process gives the yeast oxygen before pitching it into the beer. Is it enough oxygen? The inventor of the SNS method says yes, but I am not convinced. I think that some kind of aeration during the transfer from kettle to fermenter is still worthwhile. I have a wine-type aerator that I put on the end of my transfer hose. I no longer use oxygen except for very high gravity beers.

Anybody that knows biochemistry and yeast (and any cell) aerobic metabolism can tell you that there won't be any significant yeast growth if you don't oxygenate at pitching.
If you have enough viable and vital cells at pitching (whatever the method used to produce the cells) to carry the fermentation, then the wort will ferment, if not, it won't ferment completely.

Yeast growth produces secondary flavor compounds, so beer from a fermentation with yeast growth will taste differently from beer produced with no yeast growth.
Better or worse is for the brewer to decide.

Is it enough oxygen?
It depends.
Is NOT enough to produce significant growth during the main fermentation.
It may be enough to produce sufficient cells in your starter depending on many factors including initial count and vitality, nutrients provided and oxygen provided.

Sent from my SM-G981U1 using Tapatalk

If by metabolism you mean respiration, then brewers yeast can't be put in the same category as "any cell". Yeast in beer wort do not use the oxygen for aerobic respiration because of the Crabtree effect. At the sugar concentration found in even weak beer wort, yeast will always use the anaerobic fermentation pathway to multiply, regardless of how much oxygen is present. Oxygenating the wort, whether via splashing or stone, does not necessarily result in more cells, it results in stronger cells that can more easily cross the finish line.

That was not my point.
Cells, including yeast, don't have the ability to store oxygen.
So, you can't give the oxygen "in advance".

The statement "yeast will always use the anaerobic fermentation pathway to multiply" is incorrect.
You can easily disprove this by weighing the yeast biomass pitched and the final yeast biomass after fermentation under different oxygenation rates.
That's why we shake or use stir plates or bioreactors.

Can yeast multiply anaerobically? Yes, of course. But you produce much more yeast with oxygenation.

Sent from my SM-G981U1 using Tapatalk

I indeed must not have seen your point. (You are also omitting some important qualifiers in my comment.)

You implied that yeast are like any other cell in that they multiply via aerobic respiration when oxygen is present. My point was, no they don't. That's only true when the sugar concentration is below the Crabtree threshold (IIRC, <0.2% sugar concentration). Perhaps we have different understandings of the Crabtree effect.

To be honest, I don't understand most of your comment above. However, you are correct that cells do not store oxygen.

It might be worth noting in a yeast propagator there is constant aeration and the yeast produces very little co2 or alcohol in the presence of oxygen. The vast majority of available carbon goes to biomass. Many breweries have a propagator to build their own pitches and this is the considered an ideal condition in which to grow yeast. So yes, yeast do grow in both states, aerobic and anaerobic, but if you want mostly biomass, feed them oxygen. That's why this whole discussion seems a bit ignorant, this is well established biology. Aeration at pitch has a direct impact on yeast health and beer quality. Go to brewing school, they will stress the importance of proper levels of oxygen at pitch. Study the metabolism of yeast and the same thing will be pop up.

I understand it "works" for some people or so it's claimed, but it certainly isn't best practice.

Offline lupulus

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Re: Using O2...
« Reply #43 on: April 01, 2022, 06:35:13 am »




Note that Denny is now using SNS starters. That process gives the yeast oxygen before pitching it into the beer. Is it enough oxygen? The inventor of the SNS method says yes, but I am not convinced. I think that some kind of aeration during the transfer from kettle to fermenter is still worthwhile. I have a wine-type aerator that I put on the end of my transfer hose. I no longer use oxygen except for very high gravity beers.

Anybody that knows biochemistry and yeast (and any cell) aerobic metabolism can tell you that there won't be any significant yeast growth if you don't oxygenate at pitching.
If you have enough viable and vital cells at pitching (whatever the method used to produce the cells) to carry the fermentation, then the wort will ferment, if not, it won't ferment completely.

Yeast growth produces secondary flavor compounds, so beer from a fermentation with yeast growth will taste differently from beer produced with no yeast growth.
Better or worse is for the brewer to decide.

Is it enough oxygen?
It depends.
Is NOT enough to produce significant growth during the main fermentation.
It may be enough to produce sufficient cells in your starter depending on many factors including initial count and vitality, nutrients provided and oxygen provided.

Sent from my SM-G981U1 using Tapatalk

If by metabolism you mean respiration, then brewers yeast can't be put in the same category as "any cell". Yeast in beer wort do not use the oxygen for aerobic respiration because of the Crabtree effect. At the sugar concentration found in even weak beer wort, yeast will always use the anaerobic fermentation pathway to multiply, regardless of how much oxygen is present. Oxygenating the wort, whether via splashing or stone, does not necessarily result in more cells, it results in stronger cells that can more easily cross the finish line.

That was not my point.
Cells, including yeast, don't have the ability to store oxygen.
So, you can't give the oxygen "in advance".

The statement "yeast will always use the anaerobic fermentation pathway to multiply" is incorrect.
You can easily disprove this by weighing the yeast biomass pitched and the final yeast biomass after fermentation under different oxygenation rates.
That's why we shake or use stir plates or bioreactors.

Can yeast multiply anaerobically? Yes, of course. But you produce much more yeast with oxygenation.

Sent from my SM-G981U1 using Tapatalk

I indeed must not have seen your point. (You are also omitting some important qualifiers in my comment.)

You implied that yeast are like any other cell in that they multiply via aerobic respiration when oxygen is present. My point was, no they don't. That's only true when the sugar concentration is below the Crabtree threshold (IIRC, <0.2% sugar concentration). Perhaps we have different understandings of the Crabtree effect.

To be honest, I don't understand most of your comment above. However, you are correct that cells do not store oxygen.

It might be worth noting in a yeast propagator there is constant aeration and the yeast produces very little co2 or alcohol in the presence of oxygen. The vast majority of available carbon goes to biomass. Many breweries have a propagator to build their own pitches and this is the considered an ideal condition in which to grow yeast. So yes, yeast do grow in both states, aerobic and anaerobic, but if you want mostly biomass, feed them oxygen. That's why this whole discussion seems a bit ignorant, this is well established biology. Aeration at pitch has a direct impact on yeast health and beer quality. Go to brewing school, they will stress the importance of proper levels of oxygen at pitch. Study the metabolism of yeast and the same thing will be pop up.

I understand it "works" for some people or so it's claimed, but it certainly isn't best practice.
Exactly

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Offline lupulus

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Re: Using O2...
« Reply #44 on: April 01, 2022, 06:44:55 am »




Note that Denny is now using SNS starters. That process gives the yeast oxygen before pitching it into the beer. Is it enough oxygen? The inventor of the SNS method says yes, but I am not convinced. I think that some kind of aeration during the transfer from kettle to fermenter is still worthwhile. I have a wine-type aerator that I put on the end of my transfer hose. I no longer use oxygen except for very high gravity beers.

Anybody that knows biochemistry and yeast (and any cell) aerobic metabolism can tell you that there won't be any significant yeast growth if you don't oxygenate at pitching.
If you have enough viable and vital cells at pitching (whatever the method used to produce the cells) to carry the fermentation, then the wort will ferment, if not, it won't ferment completely.

Yeast growth produces secondary flavor compounds, so beer from a fermentation with yeast growth will taste differently from beer produced with no yeast growth.
Better or worse is for the brewer to decide.

Is it enough oxygen?
It depends.
Is NOT enough to produce significant growth during the main fermentation.
It may be enough to produce sufficient cells in your starter depending on many factors including initial count and vitality, nutrients provided and oxygen provided.

Sent from my SM-G981U1 using Tapatalk

If by metabolism you mean respiration, then brewers yeast can't be put in the same category as "any cell". Yeast in beer wort do not use the oxygen for aerobic respiration because of the Crabtree effect. At the sugar concentration found in even weak beer wort, yeast will always use the anaerobic fermentation pathway to multiply, regardless of how much oxygen is present. Oxygenating the wort, whether via splashing or stone, does not necessarily result in more cells, it results in stronger cells that can more easily cross the finish line.

That was not my point.
Cells, including yeast, don't have the ability to store oxygen.
So, you can't give the oxygen "in advance".

The statement "yeast will always use the anaerobic fermentation pathway to multiply" is incorrect.
You can easily disprove this by weighing the yeast biomass pitched and the final yeast biomass after fermentation under different oxygenation rates.
That's why we shake or use stir plates or bioreactors.

Can yeast multiply anaerobically? Yes, of course. But you produce much more yeast with oxygenation.

Sent from my SM-G981U1 using Tapatalk

I indeed must not have seen your point. (You are also omitting some important qualifiers in my comment.)

You implied that yeast are like any other cell in that they multiply via aerobic respiration when oxygen is present. My point was, no they don't. That's only true when the sugar concentration is below the Crabtree threshold (IIRC, <0.2% sugar concentration). Perhaps we have different understandings of the Crabtree effect.

To be honest, I don't understand most of your comment above. However, you are correct that cells do not store oxygen.
Rephrasing.
Points in my first post as follows:
1. Yeast doesn't store oxygen
2. A few hours after SNS , DO in the SNS starter is zero.
3. If no further oxygen is added at pitching, yeast will be anaerobic for the rest of the fermentation.
4. Yeast growth during the main fermentation will be minimal.

BTW
Yes, I know the Crabtree effect. It doesn't apply to this conversation.

My last post on this. Don't want to argue.

Prost everyone!



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