Pros/cons of aerating with pure oxygen

[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.

 

[LBussy]

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.

I started using a 7 gallon Fermonster for my primaries, and I don't worry about blowoff in any of my batches anymore - even some of the feisty Belgians.

 

[Schlenkerla]

I started using a 7 gallon Fermonster for my primaries, and I don't worry about blowoff in any of my batches anymore - even some of the feisty Belgians.

I'm doing the 8.5 gal fermentation bucket. Never needs a blow-off. Now that I have said that, I will have an issue from this point on...

 

[billl]

My random extra data point...

When I went to pure O2, I saw:
1) Faster starts
2) Slightly faster fermentation
3) Faster clearing

I'm not sure it made any difference in the finished product, but it seems to get to "finished" a bit faster. I can definitely see why big breweries would do it. I also suspect that you might see bigger differences in future yeast generations since they seem to be very healthy and happy at the end.

 

[Kent88]

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.

Probably not much more than "slight", unless it is a high-gravity beer, or you don't have your system figured out, or you don't make good yeast starters that will produce a sufficient cell count of a certain viability &/or vitality.

Another factor related to aeration is how much trub ends up in primary. I used to be really picky about not wanting trub. I'd add an extra half gallon to my desired batch size so I would have as little trub as possible in primary. Partly because I brew smaller batches and I couldn't afford the waste.

I am not sure on the science behind it, but trub in primary and aeration are linked as far as what they contribute to yeast health.

Since I learned that, I have always tried to get a little trub into the fermenter. Not a ton, but some.

 

[ChelisHubby]

I started using a 7 gallon Fermonster for my primaries, and I don't worry about blowoff in any of my batches anymore - even some of the feisty Belgians.

I am doing the same! I like the large fermonster lots of room and is light.so far I haven't needed a blow off rig with it.

 

[Yeastieboy]

Never mind...

 

[Mountainsax]

If you look in the "Yeast" book, they recommend 1 minute of oxygen at 1 liter per minute. I got an inline flow meter (pen style) that works good for getting a repeatable flow. Something like this
http://www.midwestsupplies.com/oxygenation-upgrade-kit

 

[MrBJones]

If you look in the "Yeast" book, they recommend 1 minute of oxygen at 1 liter per minute. I got an inline flow meter (pen style) that works good for getting a repeatable flow. Something like this
http://www.midwestsupplies.com/oxygenation-upgrade-kit

What does a flow of one liter per minute look like? Is it about when you can just see bubbles but they don't make it to the surface?

 

[orangehero]

I use 1/16 LPM flow rate and even then there are bubbles forming on the surface. I have a spreadsheet to estimate how long to flow O2 at a certain flow rate to get the concentration I want. Using 1 LPM seems to me like a big waste of O2.

 

[The_Bishop]

You need a clean .5 micron stone to get bubbles small enough to (almost) immediately dissolve.

 

[orangehero]

I use a clean 0.5 µ stone so in my experience that is definitely not the case.

You are saying that you use a 0.5 µ stone with 1 LPM flow rate and the O2 is immediately dissolving?

 

[day_trippr]

"It's Magic!"

Doesn't happen here, though. I run a .5u Williams wand at a metered .5 LPM for typically four minutes swirling like the dickens the whole time and there's at least an inch thick foam head when I'm done.

When I then load a carboy in the ferm fridge I'll first rock it around to try to capture that foam but I'm pretty sure any beneficial effect is minimal.
But it feels right

Cheers!

 

[stamandster]

"It's Magic!"

Doesn't happen here, though. I run a .5u Williams wand at a metered .5 LPM for typically four minutes swirling like the dickens the whole time and there's at least an inch thick foam head when I'm done.

When I then load a carboy in the ferm fridge I'll first rock it around to try to capture that foam but I'm pretty sure any beneficial effect is minimal.
But it feels right

Cheers!

4 minute @ .5 LPM! Wow! They seem to recommend up to 1m.

 

[day_trippr]

"They" didn't have the benefit of benchmarks set by an HBTer with a DO meter...or, apparently, Chris White's Yeast....

Cheers!

 

[55x11]

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.

Adding air with aquarium pump is definitely Ok, as long as you accept the following:

1. You are not really pumping air/oxygen into the yeast directly, you are dissolving it into the water, for yeast to use. So at the same ppm, it doesn't matter how it got there. You analogy with directly breathing 100% oxygen vs. breathing air with 20% is wrong. If you went into the space station with 22% or whatever partial pressure of O2, you wouldn't care too much if it came from pure oxygen or from air.

2. You can never get to 9-10ppm of O2 with aquarium pump.

3. You may need to run your aquarium pump for 20-30 min, while pure oxygen takes 30-60 seconds, to get to comparable values of oxygenation. Will you be sitting there watching your pump working for 20-30min?

4. You run a much higher risk of pumping your wort full of bacteria and wild yeast if you use air pump running for 20-30min than using oxygen from the tank for say 60 seconds. Especially if you don't filter your air.

In either case you should use a filter, but still, the risk with pumping room air is always higher than with pure O2 from the can.

For $10 O2 canisters, which lasts half a dozen of batches or so, for me - it's no brainer. Use O2, just don't walk away and leave it on for too long.

To me the question of - can you "over-oxygenate a wort" is sort of like asking "can you overcook and burn a quesadilla" - of course you can - if you are negligent and leave it for way, way, too long.

So in summary: Don't be negligent, follow the instructions. Don't oxygenate your standard 5G batch for more than 60 seconds or so. 2 minutes is probably still ok (think well-browned quesadilla). But 10 min or an hour is definitely NOT ok - think "burned to a crisp" quesadilla.

 

[stamandster]

"They" didn't have the benefit of benchmarks set by an HBTer with a DO meter...or, apparently, Chris White's Yeast....

Cheers!

OOOooo... link me HBTer with a DO Meter if you can ;-)

I thought the book said a max 2m for 5gal? Are you doing 10gal?

BTW, got two O2 canisters for $4 clearance at Sears a couple weeks back. Score!

 

[LBussy]

Adding air with aquarium pump is definitely Ok, as long as you accept the following:

1. You are not really pumping air/oxygen into the yeast directly, you are dissolving it into the water, for yeast to use. So at the same ppm, it doesn't matter how it got there. You analogy with directly breathing 100% oxygen vs. breathing air with 20% is wrong. If you went into the space station with 22% or whatever partial pressure of O2, you wouldn't care too much if it came from pure oxygen or from air.

You completely lost me there. My point is I am placing my word in direct contact with a strong oxidizer as opposed to a dilated oxidizer.

2. You can never get to 9-10ppm of O2 with aquarium pump.

And this is not as important as having available oxygen for the respiratory phase. One can either introduce enough for that phase all at once, or introduce it over time.

3. You may need to run your aquarium pump for 20-30 min, while pure oxygen takes 30-60 seconds, to get to comparable values of oxygenation. Will you be sitting there watching your pump working for 20-30min?

No, I'll be cleaning up.

4. You run a much higher risk of pumping your wort full of bacteria and wild yeast if you use air pump running for 20-30min than using oxygen from the tank for say 60 seconds. Especially if you don't filter your air.

HEPA filters are cheap.

In either case you should use a filter, but still, the risk with pumping room air is always higher than with pure O2 from the can.

I disagree ... filtered is filtered. What additional risk is there of introducing air for a longer period of time provided it is filtered with a HEPA filter?

So in summary: Don't be negligent, follow the instructions. Don't oxygenate your standard 5G batch for more than 60 seconds or so. 2 minutes is probably still ok (think well-browned quesadilla). But 10 min or an hour is definitely NOT ok - think "burned to a crisp" quesadilla.

This is a good analogy ... I choose to cook it on low rather than high. We should get the same thing. I do things while mine is cooking, you watch it for a short period of time. All's well that ends well.

 

[day_trippr]

[...]I thought the book said a max 2m for 5gal?[...]

Actually, it says 5.3 gallons and two minutes @1 LPM.
So, I run half the flow rate for twice the duration...

Cheers!

 

[HopWolf]

I use the BernzOmatic tank and I can't remember the last time I replaced it. I used to attach the stone to the tank via a length of tubing but seeing as though its kept coiled and likes to stay that way I've since added a length of clean sterilized copper tubing between the stone and the tank so I can control the stone location better. I hated the shaking of the carboys.
I keep the stone in a sealed container of StarSan so I don't need to boil or worry about clogs