Aeration - Is splashing into a fermenter enough?

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BeerSwiller

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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
 
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.
 
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.
 
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.
 
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.
 
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
 
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.
 
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
 
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 :)
 
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

thrasher.jpg

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.
 
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
 
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.


cooler.jpg

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.
 
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.
 
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).
 
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?
 
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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