# How Long to Oxygenate wort?



## Rickcobba (28/5/15)

Hi All, 

Can anyone help me calculate how long i need to Oxygenate my wort and at what psi? Using an oxygen cylinder and 5mm ID line, and wanting to achieve approx 15ppm.

Are there specific formulas to use to get exact results?


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## Cervantes (28/5/15)

It doesn't take long. I generally oxygenate through a stone for about 30 seconds to a minute.

I've fitted a small oxygen flow meter / control valve similar to this one and throttle it back so that lots of bubbles aren't breaking on the surface and most of the oxygen is being retained in the wort.


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## Yob (28/5/15)

Why 15ppm? Isn't 12 the magic number you don't want to go over?


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## ebyelyakov (28/5/15)

I believe 15 would be the max for high gravity wort.. 1 minute with pure oxygen.

I use airpump. Since Jamil, Ashton and other experts say it is impossible to overoxygenate with the pum, I usually leave it overnight after pitching the yeast... Pleased with results -- largers kick in after about 10-15 hrs (I use starters and ensure my pitch rates are what I want them to be).


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## bshb (28/5/15)

as far as i've read 15ppm is too high, 8-10ppm is recommended, if you are brewing a high gravity beer then you're better off introducing o2 again after 12 hours (one cell division).

given that there are a lot of factors that will effect o2 take up i haven't come across a specific formula but i did come across this..

taken from 'brewing elements series - yeast' addition: white labs ran an experiment that showed pure o2 into 20L (24°C) of 1.077 wort with a 0.5 stainless sintered stone at a flow rate of 1L per minute for 60 seconds = 9.2 ppm which is what you want.


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## Mattwa (28/5/15)

This may be of some interest. Not conclusive, but interesting all the same:

http://brulosophy.com/2015/05/25/wort-aeration-pt-1-shaken-vs-nothing-exbeeriment-results/


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## ebyelyakov (28/5/15)

A matter of opinion and experiement I guess.
BYO had slighltyl different view on the topic:
http://byo.com/hops/item/1882-fermenting-high-gravity-beers-techniques



> For wort of 15 °Plato (specific gravity of 1.061) fifteen minutes of air or *two minutes of oxygen* should be sufficient.





> For wort of 20 °Plato (specific gravity 1.083) or more, aerate up to an hour with air, or t*en minutes with oxygen *to be sure oxygen is not lacking for the yeast to grow.


I personally believe that 10 minutes of pure oxygen is heaps over the tops.. However, since most of pundits agree it is impossible to go over with the air, that's what I do -- just pump it for a bit longer.


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## Black n Tan (28/5/15)

For starters I don't think it is possible to achieve an oxygen concentration of 15ppm in beer wort. At 20C the maximum you can achieve is 9.2ppm and at 10C the maximum is 11.3ppm and this is in water (so will be less in wort). This saturation limit holds regardless of whether you use air or pure oxygen to oxygenate your wort, although it may be difficult to reach saturation using just air. I think it is almost impossible to over oxygenate wort, most of the oxygen will simply not be absorbed. There is also another factor at play and that is the higher the SG the less soluble oxygen will be in the wort. That said I use 1L/min pure oxygen for 1 minute for an average SG ale and increase this to 1.5 minutes for 1.065-1.080 ale then up to 2 mins for over 1.080, and for a really big beer say over 1.100 say 2.5 mins. The extra oxygen may not solubilise in the wort, but will be present in the headspace and replenish oxygen levels in the wort over the first few hours as the oxygen is consumed.


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## razz (28/5/15)

I use 10 gms per 42 lt batch, set the cylinder on a small kitchen scale. I did work it out a few years ago how many ppm it works out to. Although I didn't take into account the SG, temp etc.


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## Rickcobba (28/5/15)

Thanks for all your input guys! 

Its for 45L of RIS with an OG of 1.098 
I read somewhere to use around 15 ppm. 

Ive seen L/min mentioned, how would you convert psi to L/min?


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## Rickcobba (28/5/15)

bshb said:


> as far as i've read 15ppm is too high, 8-10ppm is recommended, if you are brewing a high gravity beer then you're better off introducing o2 again after 12 hours (one cell division).
> 
> given that there are a lot of factors that will effect o2 take up i haven't come across a specific formula but i did come across this..
> 
> taken from 'brewing elements series - yeast' addition: white labs ran an experiment that showed pure o2 into 20L (24°C) of 1.077 wort with a 0.5 stainless sintered stone at a flow rate of 1L per minute for 60 seconds = 9.2 ppm which is what you want.


 yeah thats what im after. But an equation that you can change the variables to suit.


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## TheWiggman (28/5/15)

I'm more interested in how you'll know if you've achieved a certain PPM of O2 in wort.

PPM = parts per million
l/min is rate of volume
psi = pounds per square inch, pressure

None of the above units have anything to do with one another. As Black n Tan said the maximum you can achieve is around 10 PPM. He also gave the flow rates. So by extension if you want to get the maximum PPM of O2 in solution using pure O2 for 40 litres of 1.098 SG you'd want 1l/min for 5 mins. Pressure is irrelevant, total delivery is what you're after so flow rate and time is all you need.


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## Black n Tan (28/5/15)

If you can't monitor flow rate, then you can just set the pressure such that you can just see oxygen bubble hitting the surface and do that for 4-5 minutes for 45L batch. That will get you close and you can adjust next time if you don't like the results. Of course I assume you have a sinter stone to deliver the oxygen, otherwise you will have to go much longer. I place the sinter stone at the bottom of the fermenter and then gently stir as i deliver the oxygen to ensure as much oxygen is dissolved as possible. Alternatively you could weigh the bottle as someone has suggested: 4L of oxygen will weigh about 5.7 grams, but you would want some pretty good scales.


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## Ducatiboy stu (28/5/15)

Does it really help to oxygenate your wort......


What are the end results....


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## BobtheBrewer (28/5/15)

Cervantes said:


> It doesn't take long. I generally oxygenate through a stone for about 30 seconds to a minute.
> 
> I've fitted a small oxygen flow meter / control valve similar to this one and throttle it back so that lots of bubbles aren't breaking on the surface and most of the oxygen is being retained in the wort.


What type of oxygen supply do you have and where did you get it from?
Bob


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## Rickcobba (28/5/15)

TheWiggman said:


> I'm more interested in how you'll know if you've achieved a certain PPM of O2 in wort.
> 
> PPM = parts per million
> l/min is rate of volume
> ...


 My question is when all you have is an 02 tank and a regulator that has units in psi, how do you know what psi will give you a flow rate of 1L/min.
Also Black n Tan stated that for OGs of 1.10 and over he uses 1L/min for 2.5mins. My og is 1.098, how did you get 5 mins?
And as for knowing what the ppm will be, I dont. And thats why im asking the question.


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## TheWiggman (28/5/15)

Ducatiboy stu said:


> Does it really help to oxygenate your wort......
> 
> 
> What are the end results....


Apart from the scientific evidence posted through the site from credible sources (MHB, Martin, DrSmurto etc)? Speeds up fermentation time and attenuates consistently. Has done wonders in my case particularly on the starter plate, get much more action and a larger volume of yeast. Since doing it I haven't had any stuck ferments or unexpectedly high finishes.
Though it's a bit like hydrate vs. dry pitch, at the end of the day you'll get beer and that's all I'm going to say about that h34r:



Rickcobba said:


> My question is when all you have is an 02 tank and a regulator that has units in psi, how do you know what psi will give you a flow rate of 1L/min.
> Also Black n Tan stated that for OGs of 1.10 and over he uses 1L/min for 2.5mins. My og is 1.098, how did you get 5 mins?
> And as for knowing what the ppm will be, I dont. And thats why im asking the question.


As BnT said, watch for bubbles on the surface. A pressure gauge won't give you an indication of flow rate in this case.
I got 5 mins because you said 40 litres. I assumed BnT did standard 23l batches. More wort = more oxygen required for same PPM in solution.


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## MaltyHops (28/5/15)

Rickcobba said:


> how do you know what psi will give you a flow rate of 1L/min.


Basically you cannot measure flow rate using pressure. You could have the O2 valve shut, opened to have a very small flow, opened to have a high flow - and it will still all be at the same pressure (assume the bottle is not near empty). Need a flow meter.




Rickcobba said:


> Also Black n Tan stated that for OGs of 1.10 and over he uses 1L/min for 2.5mins. My og is 1.098, how did you get 5 mins?
> And as for knowing what the ppm will be, I dont. And thats why im asking the question.


Could just use the try-and-see-what-happens approach - start with above recommendations and see how well it goes, add more or less next time.


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## Black n Tan (28/5/15)

Rickcobba said:


> My question is when all you have is an 02 tank and a regulator that has units in psi, how do you know what psi will give you a flow rate of 1L/min.
> Also Black n Tan stated that for OGs of 1.10 and over he uses 1L/min for 2.5mins. My og is 1.098, how did you get 5 mins?
> And as for knowing what the ppm will be, I dont. And thats why im asking the question.


My advice was for a standard 21-23L batch, so for your larger batch go for 4-5 minutes with the oxygen just breaking the surface. I typically do 40-off litres also but gave advice for a standard batch.


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## Ducatiboy stu (28/5/15)

TheWiggman said:


> , at the end of the day you'll get beer and that's all I'm going to say about that h34r:


 B)


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## Danscraftbeer (28/5/15)

What are you guys talking about? Forgive me here as a newb.
You get tanks and hoses and airstones etc to oxygenate your brews? even as small as 20lt brews????

Is there anything wrong with the 2/3 wort / 1/3 headpspace pitched correctly, seal.
Then shake to the shithouse! Then airlock.
Personally I have found great results that way without the added complications. my opt anyway. B)


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## Ducatiboy stu (28/5/15)

NB:. I have no view on oxygenating dry yeast....


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## Ducatiboy stu (28/5/15)

Danscraftbeer said:


> What are you guys talking about? Forgive me for here.
> You get tanks and hoses and airstones etc to oxygenate your brews? even as small as 20lt brews????


That was even discussed on Grumpy's :chug:


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## Cervantes (28/5/15)

Rickcobba said:


> My question is when all you have is an 02 tank and a regulator that has units in psi, how do you know what psi will give you a flow rate of 1L/min.


Click on the link in the post below. It's for a cheap meter that will tell you how many litres per minute you are using.Just install it into your air line.




Cervantes said:


> It doesn't take long. I generally oxygenate through a stone for about 30 seconds to a minute.
> 
> I've fitted a small oxygen flow meter / control valve similar to this one and throttle it back so that lots of bubbles aren't breaking on the surface and most of the oxygen is being retained in the wort.


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## TheWiggman (29/5/15)

Danscraftbeer said:


> What are you guys talking about? Forgive me here as a newb.
> You get tanks and hoses and airstones etc to oxygenate your brews? even as small as 20lt brews????
> 
> Is there anything wrong with the 2/3 wort / 1/3 headpspace pitched correctly, seal.
> ...


2 options
Air pump with aeration stone
Pure O2 kit , another example

As for the benefits, it's discussed at length in various threads. Wyeast have a good write-up regarding the tested methods and which methods are suitable for what beers. The 'shake the fermenter' method goes out the door for 60l batches, and still doesn't get desired DO for lagers.

I don't find it complicated at all to dip the aeration stone on, turn on the regulator for 60 seconds, then remove it. If it results in better beer (which to date it has) then it's money well spent. Like I said you don't need to shake the fermenter, nor do you need to step mash, nor add nutrient, nor fine etc. to get 'great results' but if those things didn't make a difference why would anyone do it?

And yes far be it for home brewers to want to complicate processes...


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## bshb (29/5/15)

Black n Tan said:


> For starters I don't think it is possible to achieve an oxygen concentration of 15ppm in beer wort. At 20C the maximum you can achieve is 9.2ppm and at 10C the maximum is 11.3ppm and this is in water (so will be less in wort). This saturation limit holds regardless of whether you use air or pure oxygen to oxygenate your wort, although it may be difficult to reach saturation using just air. I think it is almost impossible to over oxygenate wort, most of the oxygen will simply not be absorbed. There is also another factor at play and that is the higher the SG the less soluble oxygen will be in the wort. That said I use 1L/min pure oxygen for 1 minute for an average SG ale and increase this to 1.5 minutes for 1.065-1.080 ale then up to 2 mins for over 1.080, and for a really big beer say over 1.100 say 2.5 mins. The extra oxygen may not solubilise in the wort, but will be present in the headspace and replenish oxygen levels in the wort over the first few hours as the oxygen is consumed.


not sure this necessarily true, apparently in a continuation of white labs oxygen study (from yeast: the practical guide to beer fermenting) they measured the dissolved oxygen levels of 12 craft breweries and found that 9 were under 9ppm, 1 was bang on 9ppm, and 2 were above 23ppm. so i think that you can over oxygenate (which can lead to increased fusel alcohols, increased acetaldehyde). 

if you are brewing a RIS i'd make sure you give it more oxygen after 12-18 hours this will help with cell vitality and attenuation. i'd just go with 1 minute then 1 minute 15 hours later and see how it attenuates, if it doesn't fall enough add more next time.


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## Black n Tan (29/5/15)

bshb said:


> not sure this necessarily true, apparently in a continuation of white labs oxygen study (from yeast: the practical guide to beer fermenting) they measured the dissolved oxygen levels of 12 craft breweries and found that 9 were under 9ppm, 1 was bang on 9ppm, and 2 were above 23ppm. so i think that you can over oxygenate (which can lead to increased fusel alcohols, increased acetaldehyde).
> 
> if you are brewing a RIS i'd make sure you give it more oxygen after 12-18 hours this will help with cell vitality and attenuation. i'd just go with 1 minute then 1 minute 15 hours later and see how it attenuates, if it doesn't fall enough add more next time.


Yes I have read this in the yeast book. I suspect the higher DO seen is likely due to greater pressure seen in large commercial conical fermenters or may be an artefact. There is a plethora of information in the scientific literature about oxygen saturation level, so I stand by my claim that on a home brew scale I believe it almost impossible to over-oxygenate the wort. The relationship between oxygenation and fusel alcohols and acetaldehyde seems complex, with a lot of contradictory evidence as whether high or low oxygenation causes these things.


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## professional_drunk (29/5/15)

I've been oxygenating my wort for a while now. Recently I did a 1.046 wort with wyeast ringwood ale and I had accidentally run out of o2 so it didn't get my usual treatment and I didn't do any manual methods for introducing o2. This beer turned out fantastic btw. I'm starting to suspect that the importance of o2 may either be

yeast strain dependant
not required for yeast that's been exposed to o2 on a stir plate
only relevant for repitching
As for dry yeast, I did once try oxygenating a 1.055 wort that I was using notto in and the beer turned out horribly oxidized. It's as if the yeast had it's fill of o2 and left it in the wort.

I've got another wort of 1.048 ready to pitch with stir plated yeast. I'm going to try pitching it without o2 and see if I get the same results.


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## Cervantes (29/5/15)

professional_drunk said:


> As for dry yeast, I did once try oxygenating a 1.055 wort that I was using notto in and the beer turned out horribly oxidized. It's as if the yeast had it's fill of o2 and left it in the wort.
> 
> I've got another wort of 1.048 ready to pitch with stir plated yeast. I'm going to try pitching it without o2 and see if I get the same results.


Apparently dry yeast doesn't need to be oxygenated.

From the Danstar 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.

Edit:

However it does say......

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.


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## Danscraftbeer (29/5/15)

TheWiggman said:


> 2 options
> Air pump with aeration stone
> Pure O2 kit , another example
> 
> ...


hah, cool.
I'll probably have a crack at it some day too. I could only opt for the bottled pure O2 method.
I aerated water for a can brew in the past then thought twice about doing it again. Just wouldnt want to blow open air with wild yeasts via rubber diaphrams through my wort.
Watched a lengthy video of a class run by Northern Brewer explaining that for small (shakable size) brews then 1 minute shaking is enough to achive up to 8ppm. Shaking longer wont really achieve any more DO. But I still shake for 4 minutes. Bout the hardest exercise I do of late... -_-


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## verysupple (16/6/15)

Sorry to dig up an old thread, I've been researching using O2 rather than shaking the FV and came across some info that's relevant.




Black n Tan said:


> > not sure this necessarily true, apparently in a continuation of white labs oxygen study (from yeast: the practical guide to beer fermenting) they measured the dissolved oxygen levels of 12 craft breweries and found that 9 were under 9ppm, 1 was bang on 9ppm, and 2 were above 23ppm. so i think that you can over oxygenate (which can lead to increased fusel alcohols, increased acetaldehyde).
> >
> > if you are brewing a RIS i'd make sure you give it more oxygen after 12-18 hours this will help with cell vitality and attenuation. i'd just go with 1 minute then 1 minute 15 hours later and see how it attenuates, if it doesn't fall enough add more next time.
> 
> ...


It also says in the Yeast book that when White Labs did experiments using 20 L @ 1.077 that 14.08 ppm was achieved using O2 at 1 L/min through a 0.5 micron stone for 2 minutes. So apparently it may not be just fermenting under pressure that allows commercial breweries to achieve greater than 10 - 12 ppm. The Wyeast website also suggests that it's possible to get greater than that concentration.

The O2 saturations in water that BnT quoted are for water exposed to air and are determined in most part by the partial pressure of O2 in the air (that's why higher pressure gives a higher saturation point). If the head space in an FV has a higher concentration of O2 than atmospheric air - which is likely when injecting with a sintered stone - then the saturation point changes. 

Also note that it's possible to get supersaturation. So even when exposed to normal atmospheric air it's possible to temporarily have greater than 100 % saturation. If this is the case then the higher DO levels observed immediately after oxygenation would relatively quickly drop to or below saturation. However as above, the head space is likely to be oxygen rich which would slow the rate of loss and raise the saturation point.


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## Black n Tan (16/6/15)

verysupple said:


> Sorry to dig up an old thread, I've been researching using O2 rather than shaking the FV and came across some info that's relevant.
> 
> 
> 
> ...


Fair point VS and thanks for the pointing out the mistake. I stand corrected and agree that using pure O2 will provide a higher partial pressure and therefore you could achieve higher saturation than the figures I quoted. Bit of a brain fart on that. However I still think in reality that you are unlikely to over-oxygenate at the home brew level and even if you did the yeast would consume the additional oxygen within the first 12-24 hours.


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## verysupple (16/6/15)

Yeah, I agree over-oxygenation probably isn't an issue for us. Even if you do come into problems from over-oxygenation, just use less next time - problem solved.  Well, assuming you can figure out what's causing the problems.


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## Danscraftbeer (16/6/15)

This is a can of worms I cant help but bite into.
First up! How do you do this oxygenation? You just stick in an airline with an airstone and blow in the 02 (Or surrounding air)?
Is there any other circulation other than whats created by the bubbles? It wont affect the entire wort. There is always dead spots or corners (cubes). o2 wont be circulated evenly.
For an airstone to get DO levels up the levels mentioned throughout the entire contents it would take hours.
Tell me I'm wrong here.
Or shake it as well? This is home brew yeah? 



As a layman but care and concern enough. We home brewers can not ever over oxygenated when shaking the friggin fermenter! 

ps. if you could be bothered:
I'm also a _doer_ of Aquaponics.
Low DO is not good, fish can die, and many nasties that like low oxygen can happen. Think of yeast the same way.
When raising fish the more DO the better but no concern that you can over do it. Turn your fish tank into a washing machine rolling with pumped air and it just makes the fish move more. That is actually a good thing.
As for OG test results I think averages are more like 6ppm. I just cant quote that with any qualifications just a memory of something I have read and listening to.
Who has a $3000 reliable DO test equipment probe? and just which part of the wort are you testing? The top, the bottom, the corner, or the entire properly circulated, or SHAKEN thang?


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## Rocker1986 (16/6/15)

I just tip my cubes into the FV from a height and splash it around as much as I can. Works fine for me. Mind you, I do make sufficiently sized yeast starters on a stir plate as well, which probably helps matters...


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## Danscraftbeer (16/6/15)

Rocker1986 said:


> I just tip my cubes into the FV from a height and splash it around as much as I can. Works fine for me. Mind you, I do make sufficiently sized yeast starters on a stir plate as well, which probably helps matters...


Fair to say I'd guess you drink good beer.

I'm an advocate for that a wort in a fermenter with a 1/3 headspace, pitched yeast correctly and then sealed
and then shaken for 4 minutes will inoculate and oxygenate all the contents evenly and will make excellent beer.


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## GalBrew (16/6/15)

Yeah who uses oxygen. That shit is crazy......

It's really not that hard. Get a flow meter and you can work out how much you are pumping in. There is plenty of literature around about how long and at what rates to do this. Much easier than shaking the shit out of 23L of wort for 5 minutes.


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## Rocker1986 (16/6/15)

I don't even shake it :lol:, simply dump cube in and pitch yeast. Seem to get pretty vigorous ferments, they're usually pretty well finished in a few days. Certainly can't complain about the resulting beers anyway.


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## Danscraftbeer (16/6/15)

Rocker1986 said:


> I don't even shake it :lol:, simply dump cube in and pitch yeast. Seem to get pretty vigorous ferments, they're usually pretty well finished in a few days. Certainly can't complain about the resulting beers anyway.


Yeah but, you pitch the liquid yeast starter? How big? the whole starter? B)


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## Ducatiboy stu (17/6/15)

Danscraftbeer said:


> Yeah but, you pitch the liquid yeast starter? How big? the whole starter? B)


24ltr starter for a 22ltr beer.....


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## Rocker1986 (17/6/15)

Well I pitch the whole starter worth of yeast, yeah, however I crash and decant my starters so I'm not pitching 2 or 3 litres of unhopped beer as well.

I work out how big a starter I need for a given batch, then make it a litre bigger to harvest some into a quart size mason jar for the next time. It's been working well for me so far.


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## micblair (17/6/15)

10 mins of O2 at 2 L/min directly injected into the wort stream over a 45 minute transfer to the FV would result in 8-12 ppm of O2 (measured with a HQ40D). Other breweries I've worked at go for 0.5L - 1 L/min for the whole transfer. At home I don't have a flowmeter or DO meter, but I use a 2 micron stone with O2 for 3-5 minutes post pitching to help mix the yeast through.


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## professional_drunk (20/6/15)

professional_drunk said:


> I've been oxygenating my wort for a while now. Recently I did a 1.046 wort with wyeast ringwood ale and I had accidentally run out of o2 so it didn't get my usual treatment and I didn't do any manual methods for introducing o2. This beer turned out fantastic btw. I'm starting to suspect that the importance of o2 may either be
> 
> yeast strain dependant
> not required for yeast that's been exposed to o2 on a stir plate
> ...


I've just completed 2 beers which I purposely didn't use o2. Same process of stepping up on a stir plate and no aeration methods used at all except for what may occur when pouring into the fermenter.

1. wyeast ringwood ale OG 1.036.
Clean tasting, no signs of any off flavours, attenuated normally. Though lower in OG, it's good to see a repeat of the results I got last time.

2. wyeast american ale II OG. 1.048
Attenuated normally, definite off flavours. This tastes like the beers I used to make in my early brewing days. Considering whether this should go down the sink.

So as for the question of how long to o2 wort, I think if it's stir plated and used for 1 generation then the answer is strain dependant. Though take that with a grain of salt as this experimentation was hardly scientific.


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## Danscraftbeer (20/6/15)

All relevant though. We are not scientists. 

The instructions of Nottingham yeast for eg. says to hydrate with water only and aeration of wort is unnecessary.
Silly me am skeptical of that. But they are the scientists.
Its a result of my first learnings that a boiled wort is depleted of oxygen. :unsure:
After reading all this I'm more inclined not to consider trying the bottled O2 method. Far too many variables that I cant measure.
There may be more risk of over oxygenation which I didn't think possible but when it comes to Beer it is.


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## thylacine (20/6/15)

An experiment from the site "BRULOSOPHY"



*WORT AERATION – PT. 1: SHAKEN VS. NOTHING | EXBEERIMENT RESULTS!*


*"...My Impressions: *Blinded or not, I could not reliably tell a difference between these beers. I fully agree with the remarks of panelists regarding how difficult it was to tell a difference. Both beers were great, I happily drank from both the non-aerated and aerated kegs… perhaps a bit more often than I should have..."

http://brulosophy.com/2015/05/25/wort-aeration-pt-1-shaken-vs-nothing-exbeeriment-results/


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## TheWiggman (20/6/15)

This is all getting off-track and sounding a little anti-science. 
Wyeast have their recommendations and I'm sure if other yeast manufacturers were asked they would support Wyeast's recommendations and theory behind it. 
Big breweries use O2 and if it didn't make a difference I have no idea why they'd waste their money with it. 
Various yeast boffins have been quoted on this forum recommending O2 concentrations consistent with yeast manufacturers. 
Why disagree? Home brewing is chockas with unknowns and ways to go wrong. Doing a little bit in lots of areas will improve the beer, each little element may not make an apparent difference in isolation but together it's the difference between good and bad beer. 
Not sure why I'm defending it, maybe all the pros are wrong?


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## Dunkelbrau (21/6/15)

Commercials aren't wrong. 

They use a sinter stone during transfer usually as stated above (1L/m) ive seen some people do 1.5L/m as well and the fv is open to release pressure. 

The problem is the temp at transfer. If its still 26 degrees then you won't get as much dissolved as if it was 8 degrees.


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## micblair (21/6/15)

TheWiggman said:


> Big breweries use O2 and if it didn't make a difference I have no idea why they'd waste their money with it.



Tooheys when brewing Kirin Ichiban under license at the Malt Shovel use compressed air. Apparently the Japanese prefer this over oxygen (perhaps there's less risk of over oxygenation?). Breweries use medical grade O2 because its pure, sterile and dry; unlike compressed air unless you have a air drier and HEPA filter inline.


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