Pros/cons of aerating with pure oxygen

[MrBJones]

Im considering getting an oxygenation setup from Williams...the one with ss stone and ss wand. Are there any specific pros and cons that I should be aware of? Also, if using Bernzomatic canister of o2, how many five gallon batches will it do (OG 1.050).

 

[Bensiff]

If your budget allows I'd go for an actual O2 cylinder with regulator setup so you can control the flow of O2 and better determine how much you are actually injecting, short of having an oxygen meter that is your best bet for being consistent. Pro is can get into the realm of how much oxygen is recommended for your yeast, you don't have to deal with silly contraptions like air pumps that foam everything up, or strain your back shaking. Con is you have to spend money and its something else to clean.

 

[Kent88]

People here are fond of citing Brulosophy experiments, and this is one I'd love them (or another reliable beer experimenter) to repeat.

Before I go on:
Shaken vs Nothing
Shaken vs Pure O2
Nothing vs Pure O2

IMHO they screwed up the first two. In the first one they admit they screwed up, and in the second one they use a beer with an OG of 1.053, and most of the info I've read implies that the higher the OG (I believe the "magic number" is 1.070 minimum OG), the more you'll notice the difference in aeration in the final product.

From this, though, I have decided that an aeration system that doesn't involve pure O2 should be sufficient to aerate most any beer I'll brew. YMMV, to each their own, and any other cliché along those lines. While I don't take their experiments as gospel I do believe they are worth reading and that I can learn from them.

To me, each of these three experiments seems to validate each other, aeration with pure oxygen is most likely overkill. I interpret this as meaning that shaking can be enough (or just giving it a lot of time might be enough). So the wort aeration system that I bought, which doesn't use pure oxygen but probably dissolves more oxygen than shaking, is probably sufficient for high-gravity brews. I have also heard that further aeration (beyond what most brewers probably do around the time they pitch yeast) can be performed until krausen starts to subside. Not sure how much truth there is to that, though.

I think Brulosophy actually has an account here, so on the off chance that they're reading, or if anyone else who blogs/vlogs their brewing experiments, how about brewing a high volume of a high gravity doppelbock, splitting it into four, and have a Nothing vs Shaken vs Aeration System (not using pure oxygen) vs Aeration System (w/ pure oxygen) throw-down?

 

[JonM]

I've lost track of how many 5-gallon batches I get out of a little Bernzomatic tank. It's a lot. The trick is to just let enough gas out so that the bubbles are just disturbing the surface a little bit. That way, the O2 goes into solution. 60 seconds does the trick. The guys who say they get 4-5 batches out of a tank are opening the regulator full blast, which just lets the O2 out into the atmosphere rather than in to the wort.

 

[SGTSparty]

Question. Does the OG matter? I feel like the OP's 1.050 is pretty standard/low gravity/ABV so my question which is related (sorry for the potential high jack) a) at what SG do you need to aerate beyond splash/rack through a strainer b) at what SG is that not enough?@Kent88 mentioned 1.070 is that conventional wisdom? I see a lot of posts about aerating lately but not a lot of discussion as to when its needed and when its not. Sorry for the diversion but I feel like it does matter to OP as if he's doing 1.05 it might be a factor in his pro/con for pure O2.

 

[balrog]

I've lost track of how many 5-gallon batches I get out of a little Bernzomatic tank. It's a lot. The trick is to just let enough gas out so that the bubbles are just disturbing the surface a little bit. That way, the O2 goes into solution. 60 seconds does the trick. The guys who say they get 4-5 batches out of a tank are opening the regulator full blast, which just lets the O2 out into the atmosphere rather than in to the wort.

+1. I cannot remember the post on this forum but that was exactly the method--open till just see bubbles, count 60s, done.

 

[ScrewyBrewer]

After buying the stainless steel diffusor, wand and O2 valve all of my beers get a 30 second long dose of oxygen, irregardless of their gravity. That's the only way to get a larger percentage of oxygen into the wort, a much larger percentage than is available in the atmosphere. See the video below to listen to White Labs' Neva Parker explain the reasoning behind adding oxygen.....

 

[ajdelange]

They say OG matters as O2 is less soluble in high gravity wort. I've always had trouble with this but I can't deny that 20 °P wort is 80% water and 10 °P wort is 90% water so that the 20 °P wort would presumably contain, at saturation, 1 - 8/9 = 11% less O2 than the 10 °P wort per unit weight. Is this significant? If you oxygenate at 10 °P wort for a minute you should oxygenate at 20 °P wort for 66.7 sec?

Without oxygen yeast don't grow fast enough and don't, consequently, get to sufficient numbers for a robust fermentation. With too much they expend too much on the process of growing and, consequently, don't ferment as well. I have definitely experienced the former (when the oxygen that was lifting the little ball in the flow meter was flowing out the back of the flow meter instead of into the beer) but not the latter as I always over-oxygentate (> 20 ppm - as high as my meter reads). Perhaps my beer would be better if I were more careful than this but I'd rather err on the high side.

 

[MrBJones]

What's gotten me moving toward wand/stone in general is the desire to use five gallon glass carboy as my primary fermenter, but minimize handling it when full -- really a safety thing; eliminating the need to shake it is a good place to start. So is this generally a consensus:

• 30 seconds of just visible bubbles from a Bernzomatic will aerate just as well as - possibly better than - shaking
• the small canister lasts for many batches
• pure o2 might be overkill for standard gravity beers, but otherwise has no down-side. For heavier beers it's likely to provide a benefit.
• practically speaking, it's hard to over-aerate to the point of causing problems

Thanks for the replies!

 

[The_Bishop]

If you're brewing 5 gallon batches a 5 gallon carboy is not large enough. You'll lose a lot of beer in blowoff on top of having a huge chance of making a tremendous mess.

I'm not going to get into the whole 'glass carboy' thing, except to say that I don't own a single glass carboy.

Personally, I've seen benefits to pure O2. The beer seems to be 'mature' much, much quicker. I've been oxygenating wort immediately post yeast pitch.

 

[agrazela]

I oxygenate with the Williams Brewing stone/wand/"regulator" apparatus. Every batch gets 60 seconds. Since getting it I've done at least forty 5gal batches, and I just started on my third Benzomatic red O2 canister. So something like 18-20 batches per O2 canister for me. At around $10 a canister, seems like cheap insurance to me.

Here's what I do: Pitch the yeast first. Dip the stone in a mason jar of sanitizer, then open regulator until you just see bubbles. Lift the stone out and shake the wand a little to get the foam off. Use the wand/stone to stir the hell out of the wort in the carboy, to mix in the yeast and get the wort oxygenated. Return the stone to the jar of sanitizer and let that bubble a few seconds, to make sure nothing clogs the stone. Pull the stone out of the jar and shut off the regulator. Go run the whole wand and stone under the faucet to rinse off any residue. Spritz the whole wand and stone with a spray bottle of sanitizer, then put it away. Discard sanitizer from jar.

Easy peasy!

Another tip I've heard: DO NOT leave the regulator attached to the bottle. Even "off" it will slowly leak the O2, because it doesn't really seal all that well, because crappy Chinese crap.

 

[Horseflesh]

I decided to get the Williams gear with the regulator for a tank of welding O2. While it may be overkill, I like the idea of being able to add a consistent, measured amount of O2 exposure to each batch. Eliminating variables is nice.

 

[petrolSpice]

I use a similar setup and oxygenate for about 60 seconds. I adjust the valve until I see bubbles just barely breaking the surface. This is the standard method when you don't have a regulator. I use the disposable O2 cans for oxy-acetylene torches. I may look into a larger tank for welding with a regulator.

 

[Horseflesh]

I chose the Williams wand with welding tank reg because you can select the flow rate in liters per minute. I am sure the cheap Chinese reg is not that accurate, but as long as the flow rate at a given setting is repeatable, it's good enough.

 

[petrolSpice]

I chose the Williams wand with welding tank reg because you can select the flow rate in liters per minute. I am sure the cheap Chinese reg is not that accurate, but as long as the flow rate at a given setting is repeatable, it's good enough.

Where did you get the regulator? Typically they only regulator pressure, not flow rate. Either way if you set it and forget it you will have your consistency.

 

[Horseflesh]

It's the reg in this combo.

https://www.williamsbrewing.com/BIG-OXYGEN-SYSTEM--P3474.aspx

You do not set the pressure, but there is a dial for flow rate--the black knob on the left end. I assume that the reg is set to a fixed pressure and there's a variable-sized aperture to regulate the flow, but I don't know.

 

[MrBJones]

If you're brewing 5 gallon batches a 5 gallon carboy is not large enough. You'll lose a lot of beer in blowoff on top of having a huge chance of making a tremendous mess....

I've used my carboy (I think it's five gallons) for nothing but five gallon batches and - though there's sometimes a lot of foam blowoff - it hasn't been a problem one way or the other. Will using o2 cause there to be so much more foam etc that it would be an issue?

 

[Kent88]

Question. Does the OG matter?

I have White and Sainasheff's Yeast book. I shouldn't have just thrown out that 1.070 as the magic number. Their section on aeration -> high gravity beers suggests that 1.083 is the magic number. At that level and above they do recommend that at 12 to 18 hours post pitch the brewer aerate again. At 1.092 they write that the brewer must use pure oxygen, as "air will not a high enough level of dissolved oxygen".

At 1.106 they recommend you review/revise your pitch cell count and basically modify your temperature control plans to raise the ferm temp significantly after krausen falls back in.

I still think that because I have the aeration system I'll just use that instead of shaking a heavy, breakable carboy for anything more than 1.050 (less than that I'll just splash wort around when it siphons in and carefully slosh it around a bit after that), and increase time spent aerating for anything above 1.068 or so. I'll probably follow their advice to aerate again between 12 and 18 hours for anything above 1.080. I wont be following their instructions exactly (not using pure oxygen), but based on those brulosophy experiments, and figuring that the yeast book is meant for everyone from home brewers to professional craft brewers, I figure I should be alright.

Hope that helps.

Another thing to consider, even in low gravity brews, is do you plan to reuse the yeast? If so, extra focus on aeration probably wont hurt.

 

[Schlenkerla]

I have one of these..... an aeration nozzle. Use gravity and this sucker to help oxygenate. More Beer Link

I use this on the end of my keggle drain hose. Then oxygenate with the bernzomatic bottle and micron stone with a wand. Sanitized of course.

JonM made a good point about just opening the wand a little to let O2 out, no need to blow out like crazy. You waste the O2.


Another idea.

[ame]https://www.youtube.com/watch?v=ur9uwY3zem8[/ame]

[ame]https://www.youtube.com/watch?v=AG9memwcwig[/ame]

 

[LBussy]

Just a note for folks who may be using or contemplating using a pump instead of an O2 tank:

I use a pump and get results consistent with those achieved by my brew buddy who uses O2. Yes we have split batches. What I do is aerate for about 15 minutes before pitching, and then about 30 minutes after. When I do something like SkeeterPee where I am trying to blowoff some of the sulfites, extended time with the stone really helps. I do a few hours in my SP batches (in lieu of the recommended "1-2 days of gassing off").

What about the foaming you ask?

I use FermCapS, a couple drops per gallon, and get zip for foam and no blowoff anymore. It is said to settle out when the fermentation is done and it really must since it does not impact head retention on the finished beer.

"It works for me."

 

[DapperD]

So something like 18-20 batches per O2 canister for me.

Wow I must be blasting the heck out my wort cuz mine only last me about 3-4 (5 gallon) batches. I don't leave the my wand assembly attached either, so I doubt it's leaking out there. I usually just oxygenate for about 45-60 seconds...

 

[Yeastieboy]

I've been very happy with NB's Oxygenator kit and the O2 bottles available at HD/Lowes, as others have indicated. It's so much easier and cooler than anything else I have tried in the past 5 years. I've had very apparent positive results since implementing this.

I have however, been running the O2 for about 30 seconds on full-blast per NB's video. It works. O2 is cheap. Probably not going to change that.

 

[rodwha]

People here are fond of citing Brulosophy experiments, and this is one I'd love them (or another reliable beer experimenter) to repeat.

Before I go on:
Shaken vs Nothing
Shaken vs Pure O2
Nothing vs Pure O2

I think Brulosophy actually has an account here, so on the off chance that they're reading, or if anyone else who blogs/vlogs their brewing experiments, how about brewing a high volume of a high gravity doppelbock, splitting it into four, and have a Nothing vs Shaken vs Aeration System (not using pure oxygen) vs Aeration System (w/ pure oxygen) throw-down?

Vs using a whisk, which is what I use. To my sense of logic this aerates plenty well. It's cheap, quick, simple, and never leaves me rushing out to get a refill on brew day.

 

[Morrey]

I've been very happy with NB's Oxygenator kit and the O2 bottles available at HD/Lowes, as others have indicated. It's so much easier and cooler than anything else I have tried in the past 5 years. I've have very apparent results since implementing this.

I have however, been running the O2 for about 30 seconds on full-blast per NB's video. It works. O2 is cheap. Probably not going to change that.

I have the exact same setup (from the same places) as Yeastieboy. I did a beer back some months ago with a direct pitch harvested yeast slurry of WLP800. I had two pints of the slurry and used one of them in a Helles w/o making another starter, standard oxygenation shake and stir with a whisk. Fermentation took about 28-30 hours to take off at 50F.

My O2 kit came in and I decided to go ahead and make another lager the following weekend and test the O2 kit. I had the fermentation chamber running at 50F, same pitch temp, etc except I hit the wort with O2 (low bubbles) for 30 seconds. The new lager took off in 18 hours....darn near half the time of the other.

I know for a fact the yeast was pulled off the same slurry so vitality is not a question. With all variables close to the same, O2 infused wort took off like a rocket!!!

 

[pauljacks]

I'm not sure that I can tell the difference. I use my oxygen set-up for convenience and easily repeatable results. Not being a "beer nerd," from a commonsense perspective, it would seem that there shouldn't be much difference, if any, as long as the yeast gets enough oxygen for a healthy fermentation, which can be supplied by multiple methods. Just sayin'

 

[klaiguy]

I would love to see some objective evidence about the benefits of different modalities of oxygenating beer. From my knowledge of physiology, I understand that the amount of oxygen that is dissolved in solution is very small at one atmosphere of pressure even when the gas used is fully saturated with oxygen (hence hy our bodies need haemoglobin to carry oxygen efficiently). It's ability to be dissolved is also poor with most of the oxygen escaping into the atmosphere.

As the metabolic activity of the yeast which utilises the oxygen is also not an instantaneous process but one that occurs over the period of hours, how can supplying a small amount of 100% oxygen upfront at great expense be better than supplying a continuous stream of air (21% oxygen) over the first few hours of fermentation.

A good experiment would be to see how the concentration of dissolved oxygen changes over this time period when utilising the various methods. Then the second part would be subjective, but would be to see if small differences in dissolved oxygen levels made any significant difference to fermentation vitality or end beer quality.

 

[stamandster]

The thing that most lack is knowing what volume per hour of o2 is going into the wort. You can get a volume regulator, called a rotameter. Midwest sells one but its overpriced. You can get one on Amazon, https://www.amazon.com/gp/product/B019YRWTHQ/?tag=skimlinks_replacement-20 follow same guidelines as on Midwest site found here http://www.midwestsupplies.com/oxygenation-upgrade-kit

An experiment would be to use the rotameter w a electronic check valve to open at a certain interval for a certain interval over the course of a day (for instance every 4 hours for 10 seconds). Put that against the same batch with only a 60s shot at the beginning at same volume.

 

[55x11]

I would love to see some objective evidence about the benefits of different modalities of oxygenating beer. From my knowledge of physiology, I understand that the amount of oxygen that is dissolved in solution is very small at one atmosphere of pressure even when the gas used is fully saturated with oxygen (hence hy our bodies need haemoglobin to carry oxygen efficiently). It's ability to be dissolved is also poor with most of the oxygen escaping into the atmosphere.

As the metabolic activity of the yeast which utilises the oxygen is also not an instantaneous process but one that occurs over the period of hours, how can supplying a small amount of 100% oxygen upfront at great expense be better than supplying a continuous stream of air (21% oxygen) over the first few hours of fermentation.

A good experiment would be to see how the concentration of dissolved oxygen changes over this time period when utilising the various methods. Then the second part would be subjective, but would be to see if small differences in dissolved oxygen levels made any significant difference to fermentation vitality or end beer quality.

I will quote White's book on Yeast:

"Lack of dissolved oxygen causes many fermentation problems. Stuck fermentations, long fermentation times, underattenuated beers, yeast stress, and off-flavors are often the result of too little oxygen. In addition, underaerating can result in lower viability with each generation of reused yeast. For the average wort and yeast pitching rates, the proper amount of dissolved oxygen is 8 to 10 parts per million (Takacs, et al., 2007)."

Chris White, "Yeast "

"In some cases, brewers try to make up for a lack of cells by adding more oxygen to drive more growth, and excessive growth is rarely optimal for beer flavor. The wort splashing devices employed by many homebrewers will result in approximately 4 ppm, less than half the required amount. Commercial brewers using similar methods will find they get comparable results. With plenty of headspace, a strong back, and lots of vigorous shaking, a home-brewer can get levels as high as 8 ppm into the wort. This is about the maximum using air."

Chris White, "Yeast"

"Too much oxygen is rarely a problem. However, it seems that urging brewers to use lots of oxygen has resulted in some instances in which they have reached oxygen levels detrimental to beer flavor. Even though most yeast strains are able to cope with high levels of dissolved oxygen, it is possible to provide so much that it becomes a beer flavor problem. Excessive usage of pure oxygen results in high levels of fusel alcohols, increased acetaldehyde, and other flavor problems."

Chris White, "Yeast"

 

[LBussy]

As the metabolic activity of the yeast which utilises the oxygen is also not an instantaneous process but one that occurs over the period of hours, how can supplying a small amount of 100% oxygen upfront at great expense be better than supplying a continuous stream of air (21% oxygen) over the first few hours of fermentation.

"Too much oxygen is rarely a problem. However, it seems that urging brewers to use lots of oxygen has resulted in some instances in which they have reached oxygen levels detrimental to beer flavor. Even though most yeast strains are able to cope with high levels of dissolved oxygen, it is possible to provide so much that it becomes a beer flavor problem. Excessive usage of pure oxygen results in high levels of fusel alcohols, increased acetaldehyde, and other flavor problems."

Chris White, "Yeast"

These are the points I considered when I decided to use an air pump rather than O2. My belief is if I add air containing oxygen over time while the yeast is in it's respiratory phase, it will be what it needs, as it needs it.

I'm not saying adding O2 is bad, but I can imagine oxidizing some compounds in the cool wort simply by the introduction of concentrated O2. O2 is vital to us, but breathing pure O2 is often irritating to mucous membranes. My hypothesis/belief is that it can be similarly detrimental to more sensitive compounds in the beer.

Now don't get me wrong, I am NOT saying people adding O2 are wrong. I am saying that there can be too much of a good thing, and that adding air over a longer period of time has a wider margin of error than adding O2 over a very short period of time. I'm not in a rush when brewing, I have plenty of things to do while the air pump runs.

Interesting discussion!

I wonder how we could measure if adding O2 actually did negatively impact the beer, aside from subjective tests? I suppose it would first have to be one of extremes: A split batch, one half oxygenated for the standard time (30 seconds?) and one half for let's go crazy and say 10 minutes. Put them in front of a panel of judges and see what happens.

 

[plusultra]

I'm a scuba diver so I use nitrox at a 40% mix and hook one end of the feed hose to a stone and the other end to an old inflator hose that is connected to my regulator then crack the valve open for a few minutes and there you have it!

 

[thereverendmaynard]

I picked up a 40L O2 tank and this regulator from amazon. Works great.

https://www.amazon.com/gp/product/B00ZVO26C0/?tag=skimlinks_replacement-20

 

[ParanoidAndroid]

I've started wondering if an open fermentation for the first 1-3 days would be ideal.

I was thinking about some type of filter (pantyhose or similar) taped around the top for fruit flies, then some loose tin foil on top of that for smaller microbes. Both sanitized of course. Once fermentation has taken off and has been chugging for a bit, replace it with a normal airlock. Would this process act as a continuous supply of O2 for the yeast? Kind of like "Hey yeast, here's an unlimited amount of O2....use what you need to make me beer."

 

[ace3]

Is there anything wrong with using one of these "wine degassers" on the end of a drill to aggressively stir the cooled wort inside the carboy? I've done this on a few of my last batches (after having two BernzOmatic tanks go empty just sitting in a cabinet), and haven't seemed to have any issues.

I cool the wort to pitching temp, sanitize the Mix-Stir, and stir the wort so it splashes around in the carboy for a couple of minutes. I then pitch the yeast once it settles down. I seem to notice fermentation starting quite a bit sooner on the batches where I've done this.

 

[g-star]

No matter your method, you will NEVER exceed 8ppm O2 by using air. This is fine for standard and low gravity ales.

For lagers and high gravity ales, 10-14ppm O2 is required for the best results in terms of fermentation and flavor. This can only be achieved with pure O2.

Can one make a lager or high gravity ale with 8ppm oxygen? Yes.
Will it be the best it could possibly be? No.

 

[bruce_the_loon]

No matter your method, you will NEVER exceed 8ppm O2 by using air. This is fine for standard and low gravity ales.

For lagers and high gravity ales, 10-14ppm O2 is required for the best results in terms of fermentation and flavor. This can only be achieved with pure O2.

Can one make a lager or high gravity ale with 8ppm oxygen? Yes.
Will it be the best it could possibly be? No.

Using continual air to maintain 8ppm O2 for a few hours may be better than pushing to 14ppm at the start and letting the yeast consume it steadily. 14ppm allows the initial growth phase of the yeast to last longer than an 8ppm single dose, so you end up with more cells. But maintaining the 8ppm beyond the time that it takes the 14ppm to drop below 8ppm will also extend the growth phase and thus cell count.

It would be interesting for someone with an O2 meter to see what the consumption profile for both methods is. The single dose will start higher and drop off, but how long does it take for the yeast to drop it to 8ppm? If it takes an hour to drop that far, then aerating for 2-4 hours will be better for the growth, if it takes 6 hours, then not so much.

 

[BitterSweetBrews]

These are the points I considered when I decided to use an air pump rather than O2. My belief is if I add air containing oxygen over time while the yeast is in it's respiratory phase, it will be what it needs, as it needs it.

I'm not saying adding O2 is bad, but I can imagine oxidizing some compounds in the cool wort simply by the introduction of concentrated O2. O2 is vital to us, but breathing pure O2 is often irritating to mucous membranes. My hypothesis/belief is that it can be similarly detrimental to more sensitive compounds in the beer.

Now don't get me wrong, I am NOT saying people adding O2 are wrong. I am saying that there can be too much of a good thing, and that adding air over a longer period of time has a wider margin of error than adding O2 over a very short period of time. I'm not in a rush when brewing, I have plenty of things to do while the air pump runs.

Interesting discussion!

I wonder how we could measure if adding O2 actually did negatively impact the beer, aside from subjective tests? I suppose it would first have to be one of extremes: A split batch, one half oxygenated for the standard time (30 seconds?) and one half for let's go crazy and say 10 minutes. Put them in front of a panel of judges and see what happens.

I have been using an aquarium pump and a diffusion stone for a couple of years. I usually run it for 10-15 minutes or until the wort foams up to the top of my fermenter bucket. It works fine, is easier than shaking and cheaper than a oxygen setup (about a $10 one time cost for the pump, tubing and stones).

I looked at buying an oxygen setup but couldn't justify spending the $40 + O cylinder cost. You just have to run it longer than with pure 0 to make up the difference between air and pure O. I haven't done a side by side with someone with a tank, but I have read that there isn't a noticeable difference in doing it this way.

 

[MarsingRedneck]

So the yeast don'y get dizzy?

I use and have for a long time now a paint stirrer on the end of a drill for a couple of minues. Is that not as good anymore?

 

[Kilted_Brewer]

People here are fond of citing Brulosophy experiments, and this is one I'd love them (or another reliable beer experimenter) to repeat.

Before I go on:
Shaken vs Nothing
Shaken vs Pure O2
Nothing vs Pure O2

IMHO they screwed up the first two. In the first one they admit they screwed up, and in the second one they use a beer with an OG of 1.053, and most of the info I've read implies that the higher the OG (I believe the "magic number" is 1.070 minimum OG), the more you'll notice the difference in aeration in the final product.

From this, though, I have decided that an aeration system that doesn't involve pure O2 should be sufficient to aerate most any beer I'll brew. YMMV, to each their own, and any other cliché along those lines. While I don't take their experiments as gospel I do believe they are worth reading and that I can learn from them.

To me, each of these three experiments seems to validate each other, aeration with pure oxygen is most likely overkill. I interpret this as meaning that shaking can be enough (or just giving it a lot of time might be enough). So the wort aeration system that I bought, which doesn't use pure oxygen but probably dissolves more oxygen than shaking, is probably sufficient for high-gravity brews. I have also heard that further aeration (beyond what most brewers probably do around the time they pitch yeast) can be performed until krausen starts to subside. Not sure how much truth there is to that, though.

I think Brulosophy actually has an account here, so on the off chance that they're reading, or if anyone else who blogs/vlogs their brewing experiments, how about brewing a high volume of a high gravity doppelbock, splitting it into four, and have a Nothing vs Shaken vs Aeration System (not using pure oxygen) vs Aeration System (w/ pure oxygen) throw-down?

I had a bit of a chat with someone about this over on Reddit. The conclusion that I came to, is oxygenation is just another small step of many that can help to make your brew better.

My theory is if you're doing everything else right, the oxygenation will have only a slight impact on your brew. If, on the other hand you don't do much else, I believe that aerating with pure O2 could be a big help.

Absolutely no evidence to support this though, just my 2 cents

 

[MrBJones]

I've used my carboy (I think it's five gallons) for nothing but five gallon batches and - though there's sometimes a lot of foam blowoff - it hasn't been a problem one way or the other. Will using o2 cause there to be so much more foam etc that it would be an issue?

Would I have excessive blowoff and loss of wort if I keep using five gallon carboys for five gallon batches, and aerate with pure o2? I always use a blowoff hose anyway.

By the way, a five gallon carboy actually has about 5.5 gallons capacity.

 

[ChelisHubby]

Would I have excessive blowoff and loss of wort if I keep using five gallon carboys for five gallon batches, and aerate with pure o2? I always use a blowoff hose anyway.

By the way, a five gallon carboy actually has about 5.5 gallons capacity.

The blow off might be mildly increased with 0-2 but some fermcap will help control it. Why not go the the 6 gallon glass carboy, it is the same diameter as the 5 gallon and you loss much less to blow off. I found it to be a win win situation with more beer and less mess. I used a 5 gallon carboy for my first 15 or so batches, now I don't see why I would ever consider using one for more than a 4 gallon batch.