Wort Aeration

[photolimo]

It seems that there is a general consensus that having enough dissolved oxygen in your wort for healthy yeast growth is beneficial for a healthy fermentation.

What I find missing is a guideline for different methods and actual ppm results for different times using those methods on a certain plato wort.

So does anybody have any actual numbers that we can compile about aeration techniques?

Common Conclusions about Dissolved Oxygen (DO):

Minimum of 8-10 ppm for most beer styles.
Increased temperatures decrease the solubility of oxygen.
As specific gravity increases, its ability to absorb oxygen decreases
The higher the gravity, the more yeast you need, and thus more oxygen.

View attachment Wyeast-Labratories-on-Oxygenation_Gregg-Doss.pdf

View attachment Effectiveness-of-Various-Methods-of-Wort-Aeration_Fred-Johnson.pdf

View attachment Yest-A-Practical-Guide-To-Fermentation-Quote_Chris-White.pdf

View attachment Beer-Brewing-Dissolved-Oxygen_Thermo-Scientific.pdf

View attachment Are-Craft-Brewers-Underaerating-Their-Wort_Neva-Parker.pdf

 

[tagz]

I think the yeast book has some numbers on the ppm for various techniques but I don't have it handy. Basically they argue that nothing outside an oxygen tank offers enough dissolved oxygen for proper yeast health.

 

[HoppyDaze]

Spamtastic

 

[Calder]

Don't sweat it. Just aerate as much as you can and you will be OK. 99.9% of us don't have O2 and still produce decent beer and reuse yeast with no issues. Actually, you can give the wort too much O2 with an O2 set up; O2 is toxic to yeast.

 

[el_caro]

Also do not forget that if you are using dry yeast there is no requirement to oxygenate the wort.

 

[wickman6]

Is there anything wrong with using immersion chiller to aerate the wort?

I've been doing this, by waiting until the wort is cool I then plunge the chiller up and down for a minute or two. It gets a bit frothy, and I believe I'm getting some oxygen into it.

 

[scinerd3000]

Is there anything wrong with using immersion chiller to aerate the wort?

I've been doing this, by waiting until the wort is cool I then plunge the chiller up and down for a minute or two. It gets a bit frothy, and I believe I'm getting some oxygen into it.

works well. When you do high gravity beers >1.060 you can run into some problems with fermenting to the top range or the yeasts ability....

Also, aeration with actual o2 creates some other tertiary reactions such as increased ester production, faster cell division which can bypass some of the flavors which are released in lag phase of yeast development. It does increase the glycogen stores in the cell wall allowing it to withstand more stress. It also decreases trehalose synthesis which is produced by the yeast in response to stress (osmotic, chemical, temperature etc)

 

[Frogmanx82]

Is there anything wrong with using immersion chiller to aerate the wort?

I've been doing this, by waiting until the wort is cool I then plunge the chiller up and down for a minute or two. It gets a bit frothy, and I believe I'm getting some oxygen into it.

That's what I do, be sure the temp is under 140F. I wait until 120F before vigorously aerating with the chiller. Then all I do is let the cool wort drop about 3 feet into the fermenter. That aerates it pretty well. I'd never bother with an O2 system.

 

[45_70sharps]

I poured from bucket to bucket, then I got a paint mixer and put it in the old drill to get better oxygen, the I bought an O2 system.

All the methods work. Use the best one you can and run with it.
The better start you give the yeast, the better job it will do without making off flavors.
Even with pouring from bucket to bucket with beer that wasn't super high gravity seemed fine.
I only stepped up to the O2 system because it wasn't a lot of money and it improves things for the yeast. If I didn't have the O2 system I wouldn't feel like the paint mixer limited what I could make.
We're just making beer after all. After you make wort it's like it's eager to become beer. Wild yeast would get to it and make beer out of it even if you just wanted a bucket full of wort.

 

[WoodlandBrew]

Thanks for sharing that study. Shaking for 40 seconds, as recommended by Wyeast, has worked great for me. Although the highest gravity beer I have made was about 1.080.

Here is what Wyeast has:

http://www.wyeastlab.com/hb_oxygenation.cfm

 

[el_caro]

Shaking for 40 seconds, as recommended by Wyeast, has worked great for me.

Here is what Wyeast has:

http://www.wyeastlab.com/hb_oxygenation.cfm

+1 Although I shake and dance for about 2 mins.

 

[Dog House Brew]

When I contacted Wyeast, using O2 tank from Lowes and the O2 wand/stone from Williams, they responded aerate for 1 minute. They stated that you turn on the regulator just enough to see bubbles on the surface. All it told me was that I was wasting O2 and aerating too long. I too used to shake, but got tired of doing it. The small tanks and set-up are really worth it IMO.

 

[photolimo]

Thanks for sharing that study. Shaking for 40 seconds, as recommended by Wyeast, has worked great for me. Although the highest gravity beer I have made was about 1.080.

Here is what Wyeast has http://www.wyeastlab.com/hb_oxygenation.cfm

Thanks for this link very helpful. I am interested in those that are able to provide measurement to the different methods.

"It is generally safe to assume that you need at least 10ppm of oxygen."

Aquarium Pump w/ stone - 8 ppm for 5 min
Pure Oxygen w/ stone - 12ppm for 60 sec

This backs up the research conducted in the original study I posted, nice to have a scientifically measured second opinion on this: "Traditional splashing and shaking, although laborious, is fairly efficient at dissolving up to 8 ppm oxygen."

Since Wyeast did not provide an adequate method of shaking to obtain 8 ppm here is a quote from the study I posted earlier:

"The bucket was sealed with its lid and the water in the bucket was mixed vigorously by holding the bucket at the top, tilting the bucket on its bottom edge, and rocking the bucket back and forth at the rate of approximately two times per second."

It took 5 minutes to obtain an adequate level of oxygen (he did not use ppm in his study).

 

[MMJfan]

I use a grout mixer hooked to my drill to aerate and it has been working well for me! Before I got my grout mixer I poured the wort from one bucket to another and never had any problems with that method either.

 

[osagedr]

http://www.whitelabs.com/beer/NevaParker.pdf

http://www.wyeastlab.com/comm_b_oxygenation.cfm

http://www.byo.com/stories/techniques/article/indices/7-aeration/1949-aerating-wort-techniques

http://www.eutechinst.com/tips/do/09_DO_beer_brewing.pdf

 

[sweetcell]

Also do not forget that if you are using dry yeast there is no requirement to oxygenate the wort.

this is incorrect. yeast, whether from dry or liquid, need to reproduce to achieve an adequate population, and O2 is required for reproduction.

 

[osagedr]

this is incorrect. yeast, whether from dry or liquid, need to reproduce to achieve an adequate population, and O2 is required for reproduction.

Interesting; most of what I have seen indicates there is no need to aerate when using dry yeast. I still do though...

 

[bobbrews]

You can fill two carboys about halfway with wort, cover with sanitized foil, and shake the hell out of it for 60 seconds. Afterward, remove the foil, rest the carboy on the floor, and swirl the open carboy for another 60 seconds to give it some air contact. This method, unlike shaking with a completely full carboy, will give you more 02 ppm for adequate yeast health.

Cheap and effective. I've never had a problem with target FG or yeast health by doing this. In fact, I would still be doing this if someone didn't upgrade my 02 system a couple years ago as a gift.

The added benefit of a primary filled halfway (other than having a ton of oxygen to work with atop the wort) is that it will later help to create a denser CO2 blanket to protect your beer. You'll also avoid overflowing fermentations, and dryhopping in the primary will be easier if using leaf hops (more space). What about a secondary you say? Well, you could always combine the two 3 gallon batches later into one larger secondary, or keep them separate and rack to 3 gallon secondaries for dryhopping or extended aging. Added flexibility plus a two minute long arm workout > Expensive & unnecessary 02 system on the typical Homebrewing scale?... I would honestly recommend the former unless you're brewing 9-15+ gallon batches on the regular.

 

[sweetcell]

Interesting; most of what I have seen indicates there is no need to aerate when using dry yeast. I still do though...

perchance are you thinking about starters? dry yeast don't need starters since you're pitching a lot more cells and they have reserves to help them hit the ground running (you don't want to "waste" those reserves on a starter).

 

[MaxOut]

I use med grade oxygen with a regulator/flow meter and have good results. My decision to go with this set up was driven by my desire to scientifically control all aspects of the brewing and fermentation process possible in order to brew repeatably. Shaking or stirring may be an acceptable way to oxygenate but in my opinion is not a very scientific method due to too many variables. As stated in previous posts variations in oxygen levels can produce different health, behavior and growth patterns of the yeast ultimately resulting in varying flavor and aroma. I calculate the flow, volume,time and temperature to determine the exact oxygenation level required and can repeat it. Just as I take care to control the temp and time of fermentation I feel the oxygen level is just another control factor that requires consistency.

 

[WoodlandBrew]

I calculate the flow, volume,time and temperature to determine the exact oxygenation level

Wow, that's impressive. How do you calculate the oxygenation level?

 

[osagedr]

perchance are you thinking about starters? dry yeast don't need starters since you're pitching a lot more cells and they have reserves to help them hit the ground running (you don't want to "waste" those reserves on a starter).

I definitely don't make starters with dry yeast, although I always do rehydrate.

On the subject of dry yeast aeration, the following is from Danstar's website:

"I always aerate my wort when using liquid yeast. Do I need to aerate the wort before pitching dry yeast?

No, there is no need to aerate the wort but it does not harm the yeast either. During its aerobic production, dry yeast accumulates sufficient amounts of unsaturated fatty acids and sterols to produce enough biomass in the first stage of fermentation. The only reason to aerate the wort when using wet yeast is to provide the yeast with oxygen so that it can produce sterols and unsaturated fatty acids which are important parts of the cell membrane and therefore essential for biomass production.

If the slurry from dry yeast fermentation is re-pitched from one batch of beer to another, the wort has to be aerated as with any liquid yeast."

http://www.danstaryeast.com/frequently-asked-questions

Then again, this is what Fermentis has to say (credit: Revvy):

"Oxygen is required to assure a healthy cell multiplication. Oxygenation is either made by top filling and splashing wort against the wall of the fermenter, aeration or direct oxygen injection. It is usually recommended to make the oxygenation on cooled wort. At this stage hygiene is essential since bacteria may develop during the aeration. Oxygen should only be added in the first twelve hours of fermentation (9 ppm). Adding oxygen during late fermentation will increase aldehyde levels and amplify diacetyl formation. High levels of oxygen will suppress ester production. It has been noticed that oxygen can increase SO² concentrations in some worts."

http://www.fermentis.com/FO/pdf/Tips-Tricks.pdf

Can't see a downside to aerating for dry yeast.

 

[daksin]

Does anyone have data on the disadvantages of over-aerating with pure O2 and a stone? I know the problems it causes with shelf life and post-fermentation DO, I would be interested to see what it does for freshly fermented beer, though.

 

[el_caro]

this is incorrect. yeast, whether from dry or liquid, need to reproduce to achieve an adequate population, and O2 is required for reproduction.

Can you provide any evidence that refutes the expert opinion that when dry yeast is pitched you do not need to oxygenate the wort?

 

[3sheetsEMJ]

That's what I do, be sure the temp is under 140F. I wait until 120F before vigorously aerating with the chiller. Then all I do is let the cool wort drop about 3 feet into the fermenter. That aerates it pretty well. I'd never bother with an O2 system.

This is what I do as well. Although I do a partial boil, so when I pour the extra water to get it to 5gallons, I pour it from high in the air and splash it into the fermentors. This seems to aerate it just fine. I always get fermentation at 12-18 hrs, and Im not too worried about excess O2 in the beer once the yeast has used it up...

 

[photolimo]

I use a grout mixer hooked to my drill to aerate and it has been working well for me! Before I got my grout mixer I poured the wort from one bucket to another and never had any problems with that method either.

That's what I do, be sure the temp is under 140F. I wait until 120F before vigorously aerating with the chiller. Then all I do is let the cool wort drop about 3 feet into the fermenter. That aerates it pretty well. I'd never bother with an O2 system.

These seem like great methods although I am primarily concerned with what ppm these methods can produce, can anyone measure these methods at a specific gravity/temp so that we can compare?

Here is a quote from the book "Yeast":

Methods of Aeration/ Observed O2 PPM:

• Shaking for 5 minutes - 2.71ppm

• 30s pure O2 - 5.12

• 60s pure O2 - 9.2ppm

• 120s pure O2 - 14ppm

Dissolved oxygen levels with varius aeration times in 20L of wort. 18.7°P wort at 75° F (23°C). Pure oxygen injection at 1L per minute using a 0.5 micron sintered stone.

White, Chris, and Jamil Zainasheff. Yeast: The Practical Guide to Beer Fermentation. Boulder: Brewers Publications, 2010. 79. Print.

 

[Brulosopher]

I use a paint stirrer attached to a drill, works likes ****** charm! I once heard that a good yeast starter is more important than even the best oxygenation. Hmm?

 

[MaxOut]

Wow, that's impressive. How do you calculate the oxygenation level?

It's difficult to determine the exact volume of O2 in a solution without actual measurement and I do not have a measuring device. Assuming most of the oxygen was boiled out of solution gives you a vague baseline. My original formula was based off of studies done on water and I tweaked it from there. I use my own method to calculate by controlling on flow of the wort going through the injection device, set at a desired oxygen flow for a specific amount of time for X volume / wort gravity. Temperature is a factor but I always cool to the same range so it’s fixed for me. It’s not an exact science but I do it the same way every time and it gives me an extra control factor. For me the key is consistency and repeatability.

Heres a video of my recent oxygenation set up-

 

[bobbrews]

Here is a quote from the book "Yeast":

White, Chris, and Jamil Zainasheff. Yeast: The Practical Guide to Beer Fermentation. Boulder: Brewers Publications, 2010. 79. Print.

2.71 ppm when shaking for 5 minutes? Wyeast's website shows 8 ppm when shaking for one minute.

For the standard full carboy or bucket, it's probably somewhere in the middle. You're just not shaking enough air into the liquid this way. But if you vigorously shake a half-filled carboy, swirl it for a minute in open air, and then let that air blanket sit atop the wort, then you should have closer to, if not, 8 ppm 02 concentration after whipping in all of that air.

As I said before, I have done this method for hundreds of brews and never had an issue with yeast health or the quality of my final beer.

 

[WoodlandBrew]

Heres a video of my recent oxygenation set up-
http://www.youtube.com/watch?v=cvL-EJD7EH0&feature=player_detailpage

Thanks Max, nice setup!