# Aeration - Is splashing into a fermenter enough?



## BeerSwiller (24/9/13)

Hi All,

Just wondering about the aeration thing, i have always just splashed it from the cube into fermenter but wondering if this is actually enough for happy yeast or if i should be buying an aeration kit, seem to be pretty cheap from keg king ect.
I havent used yeast nutrient either so not sure if thats something i should look into doing.

Have had a few brews with a few slight off flavours and not sure whether its maybe the yeast slurry's being kept too long and directly pitched.

Thanks guys


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## GalBrew (24/9/13)

Get pure oxygen and and an airstone and your yeast will love you.


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## slcmorro (24/9/13)

Everyone knows an airstone and pure oxygen is better, but the original question he's asking is if it's enough or if a lack of aeration could be causing the off flavours? Obviously best practise and all dictates to give them as much oxygen as possible with the airstone etc, but I'm keen to hear the answer to the OPs actual question.


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## GalBrew (24/9/13)

Ok, no splashing can give up to 8ppm of disolved oxygen in wort, the same as an airstone with filtered air. Depending on the wort gravity and pitching rate and beer style, this can be ok, but probably not. But with lagers you need a higher disolved oxygen level that you can only achieve through pure oxygen delivery, hence my previous comment. There are plenty of resources out there to find that info like the Yeast book, this forum also has a link to a research paper outlining the effectiveness of different aeration methods. All agree that pure oxygen is most effective. Go buy an oxygenation kit from Connor Breware or MHB or wherever and buy your O2 bottles from Masters. IMHO air pumps are a waste of money as they can deliver the same oxygen as vigorous splashing.


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## QldKev (24/9/13)

Technically splashing a cube into the fermenter will not give you enough O2, but IMHO will get you close enough. If you read AHB all the time with ppl and their new O2 kits, will tell you how the world has changed since they have gotten one. (not knocking anyone) The placebo effect dictates it has to improve the beer by heaps. But I know a few experience brewers that long term have gotten rid of them as they say honestly they could not tell any difference in the *final *product.

But I also don't run fuel line magnets or hyclones or super duper fuel tank tablets etc on my car.


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## pat_00 (24/9/13)

Seem it's enough for me. But I don't really do lagers, so that might make a difference.

Lately I've been draining through a sterilised hop sock, I reckon it helps get more air in the wort.

You can also get these:

http://morebeer.com/products/siphon-spray-wort-aerator.html


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## GalBrew (24/9/13)

Sure, you can make great beer with no oxygenation. I just splashed for years, but I have found that my ferments are more vigorous when the wort is oxygenated, especially lagers. I have also found that oxygenation is good if you are after a super clean ferment.


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## GalBrew (24/9/13)

pat_00 said:


> Seem it's enough for me. But I don't really do lagers, so that might make a difference.
> 
> Lately I've been draining through a sterilised hop sock, I reckon it helps get more air in the wort.
> 
> ...


I also used to pour my wort through a sanitised strainer to do the same.


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## BeerSwiller (24/9/13)

Thanks for all the great info, I was thinking of buying and airpump but sounds like its a waste if time and money, might be a good thing to try injecting o2 for my lagers, I have no real problem with other beer types but things like clean lagers / pilsners ect could be better


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## pimpsqueak (24/9/13)

For me, no. I've tracked my diacetyl problem back to insufficient aeration (from splashing only).
Lately I've been filling the fermenter and running 1.5l into a sanitized 3l juice bottle and shaking until it is all foam, tipping it back in and repeating until the fermenter is full to the top with foam.
Thankfully this seems to have halted the diacetyl issue.


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## Yob (24/9/13)

Just got meself a nice new paint stirrer.. couple of minutes on high.. Only used it the once after cracking the shits with blocked airstones... <_< feckin things... you can always give it another go in 12 hours, Bribie as I recall was a fan of the double drop.

ed: sanity


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## blotto (24/9/13)

Yob said:


> Just got meself a nice new paint stirrer.. couple of minutes on high.. Only used it the once after cracking the shits with blocked airstones... <_< feckin things... you can always give it another go in 12 hours, Bribie as I recall was a fan of the double drop.
> 
> ed: sanity


I used to use my plastic mash paddle in the drill, it was a bit hard to keep in the middle of the whirlpool but it was fun


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## Bribie G (24/9/13)

I have done double drops a few times, especially when using the Thames Valley "Brakspear" yeast. Normally, even with lagers, I just give it a good thrashing within 24 hours with a 





Edit: The first lot of oxygen is used up during yeast replication, and I believe the second thrash provides more oxygen to continue the breeding up. When the oxygen is all used, it can go onto actual fermentation with an improved cell count and (they say) improved attenuation etc. Makes sense to me.


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## kierent (24/9/13)

I just pour into the fermenter, pick it up and shake vigorously side to side for a minute or 2. Gets the heart rate up. Mind you I'm only doing 22L brews, might be a bit harder with a 50L brew. having said that I haven't done enough brewing/testing to know if this practice is really having much of an effect on my finished product and I've never used pure O2 or even an aerator. Might try the mash paddle in my drill


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## Bribie G (24/9/13)

Modern breweries probably use oxygen to kick things along quicker $$$$$ but if you think about it, magnificent beers have been produced for centuries without it. A nice solution used by a lot of breweries well into the modern era was the trickle down cooler / aerator where the hot wort was trickled over refrigerated pipes.





Fig. 5.—REFRIGERATORS IN "LAGER" BREWERY OF MESSRS. ALLSOPP.
The hot wort trickles over the outside of the series of pipes, and is cooled by the cold water which circulates in them. From the shallow collecting trays the cooled wort is conducted to the fermenting backs.


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## Online Brewing Supplies (24/9/13)

This will get straight to the point, a little long but ...
Accessed here http://www.wyeastlab.com/hb_oxygenation.cfm
Oxygenation
Oxygen is a critical additive in brewing. Oxygen is the only necessary nutrient not naturally found in wort. Adding adequate oxygen to wort requires a fundamental understanding of why yeast need oxygen, how much oxygen they need, and how to get oxygen into solution and the factors affecting solubility of oxygen. 
*Why Yeast Need Oxygen*

Yeast use oxygen for cell membrane synthesis. Without oxygen, cell growth will be extremely limited. Yeast can only produce sterols and certain unsaturated fatty acids necessary for cell growth in the presence of oxygen.

Inadequate oxygenation will lead to inadequate yeast growth. Inadequate yeast growth can cause poor attenuation, inconsistent or long fermentations, production of undesirable flavor and aroma compounds, and produces yeast that are not fit for harvesting and re-pitching.

*How Much Oxygen?*

Oxygen requirement is variable depending on: yeast strain employed, original gravity of wort, and wort trub levels.

Some yeast strains have higher oxygen requirements than others. It is generally safe to assume that you need at least 10ppm of oxygen. 10ppm will supply adequate oxygen in most situations. Over-oxygenation is generally not a concern as the yeast will use all available oxygen within 3 to 9 hours of pitching and oxygen will come out of solution during that time as well. Under-oxygenation is a much bigger concern.

High original gravity (>1.065) wort, in addition to increasing osmotic stress on yeast, can cause problems with achieving adequate levels of dissolved oxygen. As the gravity of wort increases, solubility of oxygen decreases. Increased temperatures also decrease the solubility of wort.

The unsaturated fatty acids found in wort trub can be utilized by yeast for membrane synthesis. If wort trub levels are low, yeast will need to synthesize more of these lipids and therefore will require more oxygen.

*Methods of Aeration / Oxygenation*

Homebrewers have several aeration/oxygenation methods available to them: siphon sprays, whipping, splashing, shaking, pumping air through a stone with an aquarium pump, and injecting pure oxygen through a sintered stone. We have tested all of these methods using a dissolved oxygen meter and have found that, when using air, 8 ppm of oxygen in solution is the best that you can achieve. Injecting oxygen through a stone will allow much higher dissolved oxygen levels. The chart below shows methods tested and the results.

*Method* *DO ppm* *Time*
Siphon Spray 4 ppm 0 sec.
Splashing & Shaking 8 ppm 40 sec.
Aquarium Pump w/ stone 8 ppm 5 min
Pure Oxygen w/ stone 0-26ppm 60 sec (12ppm)

It was concluded that pumping compressed air through a stone is not an efficient way to provide adequate levels of DO. Traditional splashing and shaking, although laborious, is fairly efficient at dissolving up to 8 ppm oxygen. To increase levels of oxygen, the carboy headspace can be purged with pure oxygen prior to shaking. The easiest and most effective method remains injecting pure oxygen through a scintered stone.


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## Bribie G (24/9/13)

Current oxygen kits for HB require you to buy replacement cylinders. An increasingly popular option for disabled people is portable oxygen concentrators that generate oxygen rich air from normal air. The nitrogen is adsorbed into crystals then later re-released, meanwhile feeding a stream of oxygen enriched air to the patient. They are becoming popular in aquaculture and all sorts of industries that need a supply of cheap oxygen. 

I see that very small devices are now available, heading down to the $200 mark which puts them not much dearer than current pure oxygen kits. I bet if they ever got down to say $130 for example they would be a good option for brewing. Not pure oxygen but no doubt more than adequate, and the oxygen comes for free (apart from a bit of power to run the unit).


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## GalBrew (24/9/13)

A good idea, but I notice that the oxygen concentrator only enriches the air to around 30% oxygen which is only around 10% higher than normal. I wonder what levels of DO you could achieve with one of these devices?


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## Rod (24/9/13)

I use one of these

http://www.paintaccess.com.au/products/uni-pro-paint-plunger-plastic-handy-mixer?utm_source=myshopping&utm_medium=cpc&utm_campaign=Tools+and+Hardware&utm_term=Uni+Pro+Paint+Plunger+Plastic+Handy+Mixer


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## bt1 (24/9/13)

Hello all,

Previous experience form the dark side...for 60 - 200lt lt washes fermenting on grain... we use electric drills and a paint stirrer of the longer shaft type.

it fair belts a wash O2 levels up in no time and little effort....cheap and easy as well.

bt1


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## drsmurto (24/9/13)

bt1 said:


> Hello all,
> 
> Previous experience form the dark side...for 60 - 200lt lt washes fermenting on grain... we use electric drills and a paint stirrer of the longer shaft type.
> 
> ...


How did you measure the DO levels?


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## Bribie G (24/9/13)

These guys are into yield if nothing else, so worth listening to.


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## mmmyummybeer (24/9/13)

May be interested in listening to Basic Brewing Radio's podcast episode 07-04-13 NHC Aeration Experiment, To air is human released 3/7/13. It is about a home brew clubs comparisons of different aeration techniques. From memory the shake method wasn't too bad but the paint stirrer didn't fair as well, they were thinking that a paint stirrer is designed to stir without adding air. Sorry I didn't set up a link, but I didn't know how to link podcasts.
.


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## dent (24/9/13)

I ferment in closed stainless, which has the benefit of being able to put 30 odd psi (of air, or pure oxygen) in there. No air stone required.

Whether I use pure oxygen or just air, the amount of O2 that then can be dissolved in the wort increases massively - no 8ppm air limit anymore. Plus, as the yeast consume it from the wort, more will dissolve to replace it. I'll be sending my oxygen bottle back to BOC when it runs out.


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## toncils (24/9/13)

Drill heaps of tiny holes into a sanitised hose, fit it onto a bike pump.

...any better?

Thanks all, didn't realise this is such a big issue!


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## [email protected] (25/9/13)

G'day All,

Another simple thing you can do is to aerate your wort and pitch your yeast at a slightly lower temp (say 2 C) than ferment temp. The cooler wort will absorb slightly more O2. It won't make a huge difference but it will make a difference. I got this idea from a very experienced homebrewer that also brews commercially for his day job. 
Same principle as carbonating a keg when it is cold. 

Regards,
Andrew.


Edited to fix iPad autocorrect issues.


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## bt1 (25/9/13)

Howdy,

just on the paint stirrer...

if you use it as intended holding at the bottom of fermenter true it adds little O2.

Hold it near the top so it sucks air into wash so for a 60lt ferment say 40lt fill and let it rip...seriously the water will whiten up and fiz for minutes after a 5min belting with a paint stirrer attached to a drill.

The long shaft? = suits 30lt, 60lt and 200lt fermenters.

save ur self $4 and and buy the shorter one from Bunnos for 30lt fermenters.

bt1


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## Tex083 (25/9/13)

I was listening to a podcast from the brewing network and from the conclusion dry yeast required less oxygen to survive as they had been dried out in optimal state. Liquid yeasts have to chew through there energy/ foods to stay alive in the packet.
They recommended pure O2 as air pumps cause head causing proteins to react and cause poor head retention in finished beers.
I use pure O2 and a stone. Don't know if it helps but I feel it does.


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## Pickaxe (26/9/13)

What about a whisk? Bloody sunbeam mixer with beaters attached? Beer meringue?
I'm half serious.


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## scon (26/9/13)

I use a paint mixer and I get pretty damn good results imho.


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## jakethesnake559 (26/9/13)

I splash about 1/3 of a cube into the fermenter, seal it back up and shake it for a few minutes, then splash the rest of it in.
This allows me to get heaps oxygen into the wort than splashing alone.
Have noticed a quicker start to fermentation since doing this.


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## dent (26/9/13)

> They recommended pure O2 as air pumps cause head causing proteins to react and cause poor head retention in finished beers.


That sure sounds like a load of crap from the BN.

I'm not convinced a _shorter lag time = more O2_ either to be honest. Lag time is where the yeast consume oxygen. If it is very short, that would imply that there isn't much oxygen to be had. Though there doesn't seem to be much evidence that _lots of O2 = long lag time_ either. I find lag time more a function of temperature and cell count.


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