Do I really need an oxygen aeration system?

[JohanTheMighty]

I am preparing to brew a whiskey barrel stout that will be 9-10% ABV. I know how to make a good starter, I'm using a quality yeast, but I've been told I am going to need an oxygen aeration system due to the high ABV of the finished product. Do I really need this? I've brewed IPA's, strong ales, and stouts in the past with ABV's of 8-9% and didn't need one, and I don't understand why I would need one for something that will be 9-10%.

My usual routine when I make beer is to boil 3 gallons of water when I make the wort, pour two gallons of near ice cold water into my 6-gallon carboy, cool the wort enough so that when I add it to the water in the carboy it will drop to around 70% (it goes through a funnel with a screen and so I am sure this process also aerates it), and shake. I was thinking I should be just fine if I shake up the water prior to adding it to the carboy, shaking once I add the wort (which I will stirring vigorously as it cools in the ice bath), adding the yeast, and shaking again.

Any thoughts? Has anyone else successfully hit the 10% mark without one of these systems. This will probably be the strongest beer I ever brew, by the way. My usual preference is 7-8%, but this is going to be for a special occasion so I wanted to go bigger.

 

[Mexibilly]

I pour a 5 gallon batch back and forth between sanitized 6.5 gallon fermenting buckets 4 or 6 times. This results in big foam and lots of air. Pour your starter in that and you better have a blowoff tube...
If you successfully ferment 8 - 9 % beers I'm sure you'll be fine. Maybe make an extra intense effort while aerating by your normal method.

 

[MaxStout]

An O2 system is the kind of thing that's nice to have, but you can make the brew successfully without one, and many brewers do. Do lots of shaking, pouring back and forth, etc. If you have a big colander, pour the wort through that, as it will put a lot of air into the wort.

 

[slym2none]

Has anyone else successfully hit the 10% mark without one of these systems.

I brewed a 2.5 gallon barley-wine that ended up right at 11% ABV, extract kit using US-05 yeast, and the only aeration I gave my wort was a wire whisk for 15 seconds or so before pitching the yeast & closing up the FV. I had no problems, wort took off pretty quick (pitched early AM, woke up and it had krausen), and it tasted great before bottling.

 

[shetc]

I use a venturi tube

View attachment 1442967002669.jpg

 

[A2HB]

I just brewed what I hope is going to be an 11% RIS and the only aeration I did was shaking the fermenter for a few minutes. It took a good 24 hours to actually start fermenting (visibly at least) but now it's chugging along nicely. I thought I might have not had enough O2 from just shaking but I think the lag was from using yeast out of the fridge that hadn't warmed up to temp enough.

If you don't have an o2 setup I wouldn't worry about it, there's nothing you can do at this point, but hey if you can get one why not right? It can't hurt...

 

[Ungoliant]

What I do is transfer from the kettle to the carboy using a funnel w/filter. It gets nice and foamy that way, falling as far as it does. After I pitch I close up my carboy, pick it up, and shake the crap out of it. I've got a FBS clone going right now that ended up a gallon short, so it'll probably hit ~10.2%. It's going nice and slow (barely pushing the airlock), but it's had a consistent, lazy krausen going.

 

[Calder]

I have successfully brewed several 13% beers without an aeration system. I do aerate the heck out of them.

I think it documented in 'Yeast' that the better the aeration, the lower the FG, but by only a couple of points, (and I think they show a quicker ferment too).

Using an O2 system or just shaking, the maximum O2 dissolved in the wort is right after you have shaken/aerated. It starts to come out of solution as soon as you have stopped aerating, which is well before the yeast need it. For high gravity beers, I aerate a second time somewhere between 8 and 12 hours, to get the O2 level up again for the yeast. I've seen it recommended in a number of places. I think it may be in 'Yeast' too, but am not certain. Doesn't seem to hurt the beer, and my brews have done fine with it. I can't say if they would have been better or worse if I had not done it. I plan to continue the practice for high gravity beers (and Brett primary beers).

 

[JohanTheMighty]

Y'all provided a lot of helpful insight and I truly do appreciate it. I never considered using a wire wisk while I am cooling the wort in the ice bath instead of a spoon! THAT is truly a simple, yet fantastic idea! I also like the idea of splashing the beer between buckets, but I think I'm going to add an extra shaking in there by pouring in half the wort, shaking the crap out of the carboy, while there is still a lot of air in it, and then pouring in the rest before shaking the crap out of it again. Great thought everyone, just excellent, and I thank you for it!

 

[ChelisHubby]

Your brew will most likely benefit from oxygen and I would bet you would taste a difference, probably less esters and cleaner in general.

 

[JonM]

If you use dry yeast, you can get away without using O2.

Big beers need more oxygen than there is in room air, so no matter how hard you shake it, whisk it, etc., you'll never get enough oxygen. It'll ferment, but the yeast will be healthier and more likely to get to a good FG with pure O2.

 

[Ungoliant]

If you use dry yeast, you can get away without using O2.

Big beers need more oxygen than there is in room air, so no matter how hard you shake it, whisk it, etc., you'll never get enough oxygen. It'll ferment, but the yeast will be healthier and more likely to get to a good FG with pure O2.

That's interesting, because I've brewed beers over 9% without O2 using both dry yeast and liquid yeast (with and without starters) and have hit my FG every time.

So what are you saying, exactly?

 

[JonM]

It's spelled out in detail in the Yeast book. I don't have it in front of me.

 

[Ungoliant]

Ahh ok. I'll look in to picking that up.

 

[MaxStout]

That's interesting, because I've brewed beers over 9% without O2 using both dry yeast and liquid yeast (with and without starters) and have hit my FG every time.

So what are you saying, exactly?

Hitting FG every time is all well and good, but there's more to it than that. Inadequate oxygenation can stress the yeast, creating off-flavors. Yeast need O2 during the growth phase. How well this part of the process works out will affect the success of the beer later.

The Yeast book, pp79-84, discusses oxygenation in detail. Probably more detail than most of us need, but it does outline the science behind this. It recommends a level of 8-10ppm for most beers, even more for high-gravity beers. Higher O2 concentrations will help the yeast multiply faster (growth), enable fermentation to finish sooner, and result in less off-flavor contributions from the yeast.

Palmer's How To Brew also discusses this, albeit in less painstaking detail.

 

[d3track]

I would highly recommend the Yeast book, especially if you brew high gravity and/or lagers.

To your question, do you HAVE to have pure O2?- well no. Spend a good 5 minutes shaking and stirring and you'll get 6-8ppm (air is 8ppm so you will never go over that with this method). This with a big pitch will likely get you a solid fermentation and probably close to FG.

BUT (you knew it was coming)

Using pure O2 in high gravity gets you in the recommended 10-12+ppm, and this gives the yeast the best chance possible to build strong cell walls and reproduce under less stress, giving them the best chance to eat all the sugars and not throw the amount of u water by-products.

It's more about giving the optimal environment than HAVING to use the technique.

Hope that helps.

 

[Gavin C]

It's primarily a labor saving device.

Shake the snot out of the carboy, pour back and forth, or adding a venturi will all work very well. There are other ways too.

Using pure O2 takes 1-2 minutes and will get you higher levels of dissolved O2. If that is something that concerns you, oxygenation is for you.

No labor involved.

Bigger beers and lagers may benefit more as yeast management is more critical and there is less room for error perhaps.

~$60 setup, regulator, wand-stone and O2 tank

 

[Calder]

Big beers need more oxygen than there is in room air, so no matter how hard you shake it, whisk it, etc., you'll never get enough oxygen. It'll ferment, but the yeast will be healthier and more likely to get to a good FG with pure O2.

That's interesting, because I've brewed beers over 9% without O2 using both dry yeast and liquid yeast (with and without starters) and have hit my FG every time.

So what are you saying, exactly?

It's spelled out in detail in the Yeast book. I don't have it in front of me.

The difference in FG per 'Yeast' is only about .001. I doubt anyone would notice it except in a carefully run side-by-side experiment. It is less than the accuracy of the equipment we use to measure gravity.

Figure 4.2 in 'Yeast' makes it look like the difference is much more, but it does not take the beers out to terminal gravity. It clearly shows the higher O2 beer ferments quicker.

 

[kombat]

The difference in FG per 'Yeast' is only about .001. I doubt anyone would notice it except in a carefully run side-by-side experiment. It is less than the accuracy of the equipment we use to measure gravity.

As JonM said, it's about more than just the FG of the beer. It's about the potential off-flavours produced by the yeast as they struggle to reproduce without adequate oxygen. They may eventually still get down to the same (or near) FG, but the resulting beer will not taste the same.

 

[2bluewagons]

Your brew will most likely benefit from oxygen and I would bet you would taste a difference, probably less esters and cleaner in general.

I'd like to offer a counterpoint to this. When I switched from the aquarium pump to the oxygen setup shown in this thread (red can, regulator, wand, stone) most of my beers took on more of an pronounced alcohol flavor, and sometimes would give a bit of a headache during the first half-pint or so. I had heard about over-oxygenation being able to produce this effect, so kept cutting down on the time I would oxygenate, but was not able to remove the flavor from the beer.

I would have preferred to have a flowmeter on the setup to be able to be more precise in tracking the actual amount of oxygen being added, but with little effect happening from the changes I was making, I decided to just ditch the O2 and go back to aeration methods.

The beers in question ranged from 3.5% bitters to a 10.5% RIS with a variety of yeasts.

For your consideration...

 

[CaptainDucman]

Wanting to start using O2 aeration, how do you know how much O2 you are putting in? Achieving the optimum PPM.

I was at Three Weavers in LA and they were transferring to the fermenter and had a flow sight-glass with a stone aerating during the transfer... yet I read on here people just use the wand for a short time. I understand theres a huge difference between a 30bbl system and 5gallons but is it measured or just a WAG?

 

[Gavin C]

I turn on the O2 to a flow level that cause a small simmer of bubbles breaking the surface of the wort with the stone placed right at the bottom of the FV. 2 minutes.

The $10 cans last along time this way.

How do you know how much O2 is in the wort?

You don't without measuring useing a disolved O2 meter. I don't do that.

Is over-oxygenation a concern?
In theory quite possibly. In actuality on a home-brew small-batch scale I doubt it.

I certainly have not noticed any adverse consequences and have no good science to support my lack of concern. Nothing I've read on the subject however, nor my small body of competion result data are indicative of something I need to be concerned about. YMMV

 

[CaptainDucman]

Thanks Gavin,

So, in theory, scaling down the process I saw at Three Weavers (aerating during the entire transfer) I would simply regulate it down to less than a simmer whereby aerating the entire batch as it goes into the FV. Sound reasonable?

I have a tri clamp flow window, T, and a stone, so as it exits the chiller I can mount this then the exit would be to the bottom of the conical.

BK --- Pump --- Chiller --- Aeration Assembly --- Conical

 

[Gavin C]

Thanks Gavin,

So, in theory, scaling down the process I saw at Three Weavers (aerating during the entire transfer) I would simply regulate it down to less than a simmer whereby aerating the entire batch as it goes into the FV. Sound reasonable?

I have a flow tri clamp window, T, and a stone, so as it exits the chiller I can mount this then the exit would be to the bottom of the conical.

BK --- Pump --- Chiller --- Aeration Assembly --- Conical

When it comes to inline oxygenation I have no experience so am no use to there I'm afraid.

 

[PlexVector]

I'd like to offer a counterpoint to this. When I switched from the aquarium pump to the oxygen setup shown in this thread (red can, regulator, wand, stone) most of my beers took on more of an pronounced alcohol flavor, and sometimes would give a bit of a headache during the first half-pint or so. I had heard about over-oxygenation being able to produce this effect, so kept cutting down on the time I would oxygenate, but was not able to remove the flavor from the beer.

I would have preferred to have a flowmeter on the setup to be able to be more precise in tracking the actual amount of oxygen being added, but with little effect happening from the changes I was making, I decided to just ditch the O2 and go back to aeration methods.

The beers in question ranged from 3.5% bitters to a 10.5% RIS with a variety of yeasts.

For your consideration...

Fusel alcohols possibly? But this is usually from higher fermentation temps. Maybe the higher O2 concentrations allowed the yeast to run "hotter" than your "normal" if the temp is not being controlled very well?

 

[slym2none]

Wouldn't pitching a healthy amount of viable yeast mean not needing oxygen? I thought the point of O² was to give the yeast something they can use to reproduce in numbers great enough to tackle your beer.

It seems to me with these huge starters that can be made, O² isn't really necessary... but I am still a noob, learning as I go. Please correct me if I'm wrong.

 

[Gavin C]

I for sure see your point @slym2none but I think that if you really want to stack the deck in your favor you should consider doing both.

Targeting an appropriate pitch rate ensures you have a sufficiently large herd of yeast to chew on the fermentable sugars

Ample oxygen will optimize the health and metabolism of this herd.

 

[slym2none]

Thanks for clarifying that, Gavin!

 

[Gavin C]

Thanks for clarifying that, Gavin!

No worries. That is my crude understanding of things anywhoo.



BTW. I thought your avatar was "slender man". Slym = slender,

 

[MaxStout]

Wouldn't pitching a healthy amount of viable yeast mean not needing oxygen? I thought the point of O² was to give the yeast something they can use to reproduce in numbers great enough to tackle your beer.

It seems to me with these huge starters that can be made, O² isn't really necessary... but I am still a noob, learning as I go. Please correct me if I'm wrong.

I was sifting through White & Zainasheff's book Yeast, and it goes into quite a bit of detail as to why O2 is necessary. Until now I also thought it was just about yeast growth, like you mentioned. However, the authors give an in-depth discussion of the aerobic phase of fermentation and the need for oxygen. They state that O2 is necessary for the yeast to synthesize sterols. It's a lot of science, but a good read. If you have the book, it starts on p75.

 

[slym2none]

No worries. That is my crude understanding of things anywhoo.



BTW. I thought your avatar was "slender man". Slym = slender,

Heh - nope, Mr. Gone, from The Maxx.



Thanks again!

 

[Bellybuster]

sloppy-old-slurry-no-starter-vs-fresh-yeast-exbeeriment-results/

wort-aeration-pt-2-shaken-vs-pure-oxygen-exbeeriment-results/

Food for thought.

For what it's worth, I gave up on using O2 years ago. Spending money with no noticeable impact on the product just didn't make sense to me. Not to mention, without a proper meter, you have no idea if any O2 at all is being absorbed. There sure is a ton of waste bubbling up through the surface. Inline would be the best bet.
I'm sure others see an impact, I never did.

 

[JohanTheMighty]

Well, so far it looks like I've done well aerating it. I used a wire whisk to stir the cooled wort (capital idea, Mr slym2none), I poured half into the carboy through a screen in my funnel, picked it up and shook it, poured the rest through the screened funnel, put a drilled bung on it and, worth noting, shook the carboy like I was strangling it. I've managed to keep my closet at about 72 degrees and, following an impressive fermentation start, has been bubbling along for about 5 days now. I have a really good feeling about this!

I'd post a pic, but it's just gonna look like a carboy filled with stout. Nothing impressive to note from a pic.

 

[KPBrews]

I have successfully brewed several 13% beers without an aeration system. I do aerate the heck out of them.

I think it documented in 'Yeast' that the better the aeration, the lower the FG, but by only a couple of points, (and I think they show a quicker ferment too).

Using an O2 system or just shaking, the maximum O2 dissolved in the wort is right after you have shaken/aerated. It starts to come out of solution as soon as you have stopped aerating, which is well before the yeast need it. For high gravity beers, I aerate a second time somewhere between 8 and 12 hours, to get the O2 level up again for the yeast. I've seen it recommended in a number of places. I think it may be in 'Yeast' too, but am not certain. Doesn't seem to hurt the beer, and my brews have done fine with it. I can't say if they would have been better or worse if I had not done it. I plan to continue the practice for high gravity beers (and Brett primary beers).

How are you "aerat[ing] the heck out of them"? The usual "shake it like a British nanny", or some other system?

And more importantly, how do you do the second round of shaking? Pull the airlock, sanitize your hand to plug it, and shake it up by hand again? I think I like your line of thinking, with the second aeration pass 8-12 hours in.

I think I'm with the crowd that's not inclined to bother with true oxygen-based aeration, given the larger number of reports of success without it.

And yes, coming from the high tech aquarium world, where we deal with dissolved gasses in liquid regularly, testing is nearly impossible without serious scientific gear, and not really worth it outside of a lab. Using a stone with the finest possible bubble size will maximize absorption into the water column before it breaks the surface. Once it hits the surface, it's gone. Just be glad that o2 is a lot easier to get into solution than co2 is!