# O2-ing my wort



## _Mick_ (18/12/14)

After some advice on getting the right gear to give my wort a nice O2 injection prior to pitching.
I want to get serious with my lagers and this seems like the next step for me.


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## Florian (19/12/14)

If this seems like the next step for you, then there is plenty of searching to be done. A few different systems available, most of which have been extensively covered.

I myself use the morebeer setup with a 0.5 micron stone on a 700mm long stainless cane, coupled with a disposable benzomatic cylinder (masters and others have them, Bunnings only as special order). the reg is from morebeer also, more like a simple valve without any indication of flow rate. Works well enough but would like a better reg.

There are other systems around like the one MHB used to offer, better reg but only tubing, no ss cane. 

Sadly (but for good reasons I suppose) in Australia we can't just buy reusable O2 cylinders (think Co2 bottle but for O2) outright like in the US These are available for hire for trade and health services etc, but the cost to hire make it uneconomical unless you brew heaps and heaps and heaps. With those O2 bottles also come decent regs and attachments (flow rate meters), think hospitals (both wheelchair and wall outlets). 
(And no, don't even think about snatching one off a wheelchair, it's a nice thought when you're sitting in the waiting room totally bored, but no, just don't go there)

Safety advice: Take care when handling O2 tanks as serious injuries and explosions can occur when handled with greasy hands etc, please do a search and familiarise yourself with correct handling procedures.


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## wynnum1 (19/12/14)

Hospitals and industry produce 02 on site .I think it is filtered out of the atmosphere not pure but good enough .Portable _Oxygen Concentrator may be worth trying _


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## TheWiggman (19/12/14)

I just bought a kit from Barleyman for $140 and it has a flow meter. A good price from what I've seen. Haven't used it on a brew yet but I'm in the same boat as you, taking all necessary steps to nail lagers.


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## _Mick_ (19/12/14)

Anyone thought of just adapting a blowtorch with some tubing and a Ss airstone just screwed onto a benzo disposable O2 bottle?


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## Dan2 (19/12/14)

_Mick_ said:


> Anyone thought of just adapting a blowtorch with some tubing and a Ss airstone just screwed onto a benzo disposable O2 bottle?


There are kits available that use those disposable bottles.



TheWiggman said:


> I just bought a kit from Barleyman for $140 and it has a flow meter. A good price from what I've seen. Haven't used it on a brew yet but I'm in the same boat as you, taking all necessary steps to nail lagers.


Looks like this setup is based on one variation of those disposables.
I forked out over $400 for a dive O2 bottle (3kg I think) with basic reg to drop pressure, ball valve to slow flow, and one of the Barleyman plastic flow meters to fine tune flow. The flow meter supplied with Barleyman's rig looks hard to tune around the 1/2 - 1 L/min mark which should be where you want it, where as the one they supply separate is perfect for the job.


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## TheWiggman (19/12/14)

Close Dan2. I gave it one run on a starter earlier this week and found that once the 02 was in it would pressurise the line and continue to leak out for about 30 secs. For something as small as a starter (1.5l) I only had to turn the regulator on until gas came out, then closed it off. If kept on I think it would be easy to regulate at around 0.5l/min. In all honesty the reg does have a cheap feel about it but it was a cheap kit, and is fine for its purpose.

This was on a October use-by of WLP005 and let me tell you it went nuts. I gave the boil a pinch of yeast nutrient and after 48 hours there were yeast solids churning around the stir plate. Like a snow storm inside the flask. I've never seen the yeast coagulate like that in a starter.
All this talk about yeast health is making me damn thirsty for this ESB...


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## sp0rk (19/12/14)

Bunnings in Coffs has the gas bottles and the regulators to suit, you'll just need to source a stone
I'm thinking when I get mine mine I'll solder a length of copper tube to the stone to use as a sanitizable cane


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## professional_drunk (19/12/14)

Do a search and you'll find I detailed a build for this. A cane is not necessary for this setup if you store your vinyl tube straight, you'll have no problem reaching the bottom of a carboy.


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## srm (19/12/14)

Not for everyone but ... 

Years ago I imported an Oxygen Concentrator that I won on ebay to replace hired oxygen cylinders for my other-half's LPG/oxygen lampwork torch. An oxygen concentrator continuously takes atmospheric air (80% nitrogen / 20% oxygen) and expels 95% oxygen through a 0 to 5 litres per minute flow meter. 

I now use this oxygen concentrator together with vinyl tube, air filter and stone to oxygenate my wort.


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## mattfos01 (19/12/14)

professional_drunk said:


> Do a search and you'll find I detailed a build for this. A cane is not necessary for this setup if you store your vinyl tube straight, you'll have no problem reaching the bottom of a carboy.


Mate you did and an awesome how to it is, but the tradeflame brand bottles from Bunnings, like the barleyman kit, take a different size reg to the oxyturbo bottles.


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## Gelding (19/12/14)

what is wrong with filtered air ?


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## schoey (19/12/14)

Gelding said:


> what is wrong with filtered air ?


Nothing, but there's a limit of how much O2 you can get in solution with air. The limit for pure O2 is higher.


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## Batz (19/12/14)

TheWiggman said:


> I just bought a kit from Barleyman for $140 and it has a flow meter. A good price from what I've seen. Haven't used it on a brew yet but I'm in the same boat as you, taking all necessary steps to nail lagers.


That seems a fair deal.

I'm building my own atm, I'll post pics when finished.

I do brew lagers and pilsners now and then and I believe an 02 aerator, or whatever we call them will be a huge help.

Batz


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## _Mick_ (19/12/14)

sp0rk said:


> Bunnings in Coffs has the gas bottles and the regulators to suit, you'll just need to source a stone
> I'm thinking when I get mine mine I'll solder a length of copper tube to the stone to use as a sanitizable cane


That's what I had my eye on mate, might give it a go over the weekend when i do my Hog clone


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## Gelding (19/12/14)

schoey said:


> Nothing, but there's a limit of how much O2 you can get in solution with air. The limit for pure O2 is higher.


I hear you but air is free while pure o2 is expensive and when you bubble o2 through wort I'd argue most of it ends up in the atmosphere and not in solution. By definition if bubbles exit from the top of the fermenter thats pure o2 wasted.

I question the economies of O2 injection as such...


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## Goose (19/12/14)

Oh dear.

I believe people get as passionate about this debate as they do about whether to rehydrate yeast or not.

I did read this in an American , admittedly dated 2006 :



> Reading the latest edition of John Palmer's "How To Brew" (great book BTW), and he states that he gets better fermentations using filtered air rather than pure oxygen, and also cites a Zymurgy article that said that wort injected with pure oxygen tasted thinner and weaker than that aerated with filtered air.


Hmm, skimming the yeast section I cant find this, perhaps it was removed in later editions for good reason .... :blink:


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## schoey (19/12/14)

Gelding said:


> I hear you but air is free while pure o2 is expensive and when you bubble o2 through wort I'd argue most of it ends up in the atmosphere and not in solution. By definition if bubbles exit from the top of the fermenter thats pure o2 wasted.
> 
> I question the economies of O2 injection as such...


Yes air is free and pure O2 isn't, but that's not the point. You can buy cheap malt and hops and replace a portion of the grain bill with cane sugar and still make very good beer and save money. An O2 setup costs around $100 if you buy from the right sources and will last somewhere between 20 and 100 batches depending on the specific setup. I don't use much (if any) pure O2 on every batch but lagers and high gravity ales I do and the results are measurable both quantitatively and qualitatively.


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## Bomber Watson (19/12/14)

Stupid question, is industrial O2 the shit were after?

I have an oxy/accet setup in the shed....complete with....wait for it...oxy bottle, reg, etc....Already paying rental on the bottle for it to sit there and be used occasionally....

Hmmm, starsan my blowtube and a nice small welding tip and just dunk it in the fermenter with the valve cracked a bit.......(joke)

Cheers.


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## michaeld16 (19/12/14)

Bomber Watson said:


> Stupid question, is industrial O2 the shit were after?
> 
> I have an oxy/accet setup in the shed....complete with....wait for it...oxy bottle, reg, etc....Already paying rental on the bottle for it to sit there and be used occasionally....
> 
> ...


I would give that a go no joke i thought the only difference was something to do with the bottles themselvrs industrial or hospital grade i thought whats inside is the same, happy to be corrected on this one


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## Bomber Watson (19/12/14)

Obviously i would jerririg a silicone line onto the reg and use an aration stone or similar as opposed to the blowtube idea......But yeah, just wondering....

Small feed of 02 into a fermenter for 24 hours would probably use as much gas as 5 minutes with a #12 cutting tip...So SFA....

Cheers.


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## roastinrich (19/12/14)

Bomber Watson said:


> Stupid question, is industrial O2 the shit were after?
> 
> I have an oxy/accet setup in the shed....complete with....wait for it...oxy bottle, reg, etc....Already paying rental on the bottle for it to sit there and be used occasionally....
> 
> ...


Mate thats exactly what I've got, except I use a silicone hose and a sintered stone on a G sized bottle. I get my worts krausening within 6 hours and attenuating down to 1006 best Ive ever got. Shoot a load in for about 45 secs and then whack the glad wrap rain coat on.


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## Bomber Watson (19/12/14)

Boyah!!!

Cheers mate.


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## _Mick_ (19/12/14)

Sh$t why did I not think of that? I have a dirty big oxy at work, looks like that bad boy might be repurposed...


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## Bomber Watson (19/12/14)

Takes all types...I had to be drunk to think of it 

45 seconds is way better than what i was thinking, chap as chups bruh!.


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## TSMill (20/12/14)

Florian said:


> Sadly (but for good reasons I suppose) in Australia we can't just buy reusable O2 cylinders (think Co2 bottle but for O2) outright like in the US These are available for hire for trade and health services etc, but the cost to hire make it uneconomical unless you brew heaps and heaps and heaps.


You can get a D sized oxygen cylinder at Bunnings:

http://www.bunnings.com.au/-trade-n-go-gas-coregas-oxygen-size-d-gas-cylinder-deposit_p5910224


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## Florian (20/12/14)

that's cool, just need a reg and good to go.
and get them into qld somehow...

wonder how much they charge for the o2.


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## tateg (20/12/14)

Can you just attach a micromatic reg to these o2 bottles 
https://m.masters.com.au/mob/product/900001620/bernzomatic-disposable-oxygen-cylinder-40g.jsp


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## Florian (20/12/14)

tateg said:


> Can you just attach a micromatic reg to these o2 bottles
> https://m.masters.com.au/mob/product/900001620/bernzomatic-disposable-oxygen-cylinder-40g.jsp


No


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## Danscraftbeer (18/3/16)

To rehash this topic. I ask the hard question: Is bottled o2 the same? I'm set up with an o2 bottle now that's for welding purposes.
Food grade seems unobtainable for a novice brewer. Try it. 

Just got this soap taste in the last (green brew taste test) that I injected with bottled o2 with the pitched starter for pressure ferment. Maybe just green beer paranoia. :huh:


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## jibba02 (18/3/16)

I use a welding cylinder from bunnings and have done for a long time. Never any problems with it. For the most part the o2 is the same as medical grade. The difference is un the handling and transfer. Medical cylinders have a one way valve so when the regulator is disconnected there is no possibility of contaminating the cylinder. As far as bacteria or any other organisms living in the cylinder, it is impossible for anything to survive in pure oxygen.


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## Danscraftbeer (19/3/16)

Not worried about bacterial. Its a soap taste. I sanitized and final rinsed with boiled water prior to every step. The only thing I did different is the new technique of bottled o2 and shake rather than the 1/3rd head space of the air around you at the time etc. and shake to oxygenate the wort. I cranked in the pressure of o2 though. so I'm sure I've got a higher level of o2 in the pre fermented brew then I have ever.

Edit: So maybe there is something to filtered air compared to bottled o2.

How does a home brewer use filtered air to oxygenate wort?


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## evoo4u (19/3/16)

Edit: So maybe there is something to filtered air compared to bottled o2.
_________________________________________________________

Just a thought here - since yeast requires a goodly amount of oxygen to multiply and do the fermentation (which is why we use pure O2, to get sufficient into the wort), it could be that an O2 infused wort might finish at a lower FG than one with an inadequate supply of O2, as might result from using air rather than pure oxygen.

So, lower FG = 'drier' beer = (possibly described as) thinner beer.

The caution of course is not to overdo the O2. From what I've read, about 60 - 75 seconds blast for 23 litres wort.


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## Danscraftbeer (19/3/16)

Its a flavour thing I'm unfamiliar with at the moment. Tanked injection? Can you trust any tank of o2?

edit: I respect the closed system of brewing. Then again there may be something in more open brewing too. For the home brewer especially. That's a nice thought in the overall brewing evolution.

This takes me back to a thought: Our ego to think we can do it better than nature. To set up closed systems only exposed to man made manufactured environments thinking its better than the free natural air around us. Duh!

Then again if your in a confined environment with lots of people and pets running around then that's going to be part of your brew as well.


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## MHB (19/3/16)

Soapy flavours can have a few causes, but the big one is Lipids and their metabolite products.
Usually adding the right amount of O2 helps, if you used too much you can poison your yeast, if the yeast pitch is less healthy or too small, that to can cause problems.
Not the only cause, and it might be worth doing some more research and taking a closer look at your process.

Wort quality, a wort without too much trub, enough FAN and the right amount of healthy yeast should fix the problem.
Mark


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## GalBrew (19/3/16)

Plenty of people use welding oxygen with no issues. Your oxygen wand should have a sterile in line filter to ensure nothing gets in your wort (not that there would be anything). You should invest in a flow meter so you know the volume of oxygen you are injecting into your wort. 1L of oxygen for a 23L batch of ale should be ample. I have personally never noticed a soapy taste when using oxygen.

'Goaty'....yum.


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## jibba02 (19/3/16)

By the sound of it your pumping o2 into the headspace and shaking the fermenter? Not using a stone?


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## MHB (19/3/16)

I used an Industrial O2 bottle for years. Cant think of any reason why you wouldn't if you had access, in a perfect world you would as mentioned above use an inline filter and an inline carbon filter, I only ever used an inline HEPA just to prevent any particulates blocking up the airstone from the inside.

Without a dissolved oxygen meter its really a bit of a guess as to how long and hard to aerate, might be worth doing a bit of reading on how to get the target 10ppm (give or take) into solution.



Danscraftbeer said:


> Its a flavour thing I'm unfamiliar with at the moment. Tanked injection? Can you trust any tank of o2?
> 
> edit: I respect the closed system of brewing. Then again there may be something in more open brewing too. For the home brewer especially. That's a nice thought in the overall brewing evolution.
> 
> ...


Dans
There is a lot there that worries me, if you have a look at the very few open fermenters still used commercially I think you will find that they are all open to a closed room with sterile (or at least very clean) air. Open fermentation under most any other arrangement is a recipe for infection.
Fundamentally, yeast wants to make yeast, making alcohol is largely a response to the environment we create, good beer is far from a result random exposure to a "natural" environment.
We as brewers are manipulating the yeasts natural inclination to make more yeast and using its ability to make alcohol to do something we want - turn wort into beer. It isn't Ego to think that if we modify the water, take carefully malted barley and process it just right - end product being good beer. If we let random products and processes intrude the odds are that the beer wont be as good.
"Can you trust any tank of o2" YES - a lot more than you can trust the air around us.
M


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## manticle (19/3/16)

Nature is wonderful and delightful a lot of the time but also bring us bubonic plague, syphilis and dysentery.


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## Danscraftbeer (19/3/16)

Thanks for the insight guys. Going by the page MHB posted I'm doing all things right. As in preventing this flavour. At a loss what's happened.



jibba02 said:


> By the sound of it your pumping o2 into the headspace and shaking the fermenter? Not using a stone?


Yes. I purge with o2 best as possible. When seeled I inject the o2 in the dip tube. I read someone's notes here who experimented with a dissolved oxygen meter. They o2 the kegmenter to 4psi. Then shake well for a few minutes. That gets in the ballpark of 10ppm.


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## Chridech (19/3/16)

I use the oxygenation rates quoted in Chris White's and Jamil's Yeast book. The experiments White Labs performed showed that using pure 02 at a flow rate of 1L/min with a 0.5 micron stainless steel sintered stone, in a 1.077 SG 20L Wort at 24C, resulted in 9.2ppm for 60 secs and 14.08ppm for 120 seconds. I therefore inject pure o2 for 90 secs to get within the 10ppm ballpark. Works for me. 

I'm fortunate to have access to medical grade O2, as I lease a cylinder and reg for my office. Can't see there would be any problem with industrial O2 cylinders, especially with a Hepa filter.


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## Danscraftbeer (22/3/16)

HEPA filter. I need something to put on the (research and next addition) list.
As for my worries of a soap taste of my latest brew. After a week in the kegerater it seems to have gone! Its now the nice clean full flavoured beer its planned to be.

It wasn't the oxygen I'll conclude.
Its more likely a change of yeast, pressure fermented with late hop additions. All the (fumes) of your hops being captured in your beer instead of blowing off and lost. Ageing is the key to the nice perfect blend of your beer. Heavy hopped beer pressure ferment beer can be fumey when green.
Don't panic! Give it time. B)


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## Mardoo (22/3/16)

There's something about soapy taste, hopping rate and pH I ran across recently. Let me see whether I can scare it up again.


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## Mardoo (22/3/16)

OK, I couldn't find the original reference at the moment ( I know which HBT thread it's in, but it's over 4000 posts long). This sums it up though. Apparently high final pH can lead to soapy hop flavours. I've had it in many IPA's and very few other beers. Ignore the stuff from the first edition of How to Brew. It's been pretty clearly shown that leaving beer on the trub or lees for even two months isn't likely to lead to soapy off-flavors.


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## MHB (23/3/16)

Mardoo - I don't agree, mind you if it was a cut and dried argument I doubt that thread would have gone on for 4000 posts.
There are several causes of soapy flavours, the most common is I believe "soap" not cleaning out all the remains of chemicals. There are also lots of other reasons (including lipids being extracted from trub) to get beer off *OLD* yeast and other trub material, that's very different to having some of the late settling yeast in contact with the beer during maturation, that can be beneficial - with in limits.
A little late sedimenting yeast being OK doesn't equate to all the trub being a good idea, any commercial brewer working in a CCV would have done 2-3 yeast drops before maturation, in a flat bottom tank the beer would have been racked at least once probably twice.
pH can be very important, high pH values can cause lots of problems, low pH has a number of benefits especially suppression of a lot of bugs and slowing yeast autolysis.
One reasons to rack is the formation of Protease A and the effects it has on head. Not important if you don't want head on your beer but that would be a minority of brewers. There is always a problem when we look at the effect of any one process/ingredient in isolation without considering the effect on the whole process and the beer we make.
Mark


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## nosco (31/3/16)

Im having a bit of trouble sourcing a reg for these bottles. The conversion kit they had at Masters didn't fit their o2 bottles. They would only fit the same brand bottle as the reg which only had argon and another. Bunnings had a similar looking kit (it looked exactly the same but different brand) but they had no o2 in stock for me to test it out on. Reece plumbing (2 different stores) had the bottles but didn't seem to stock the regs. Maybe if I asked for a conversion kit? Im looking at one on eBay but it has a 10mm thread to go on the bottles. The ones they sell at Reece are 12mm so if I get the eBay one I might have trouble getting more bottles for it. I like the eBay one coz it has a gauge on it. It also looks the same as the bunnings and masters ones except with the gauge. Makes me think it might not fit other bottles i can buy at a hardware shop.

I can get a the brass ones that go on the Bernzomatic bottles at a decent price but the Bernzomatic bottles are only 40g. It seems a pretty pricey bit of kit as it is. Any one bought one recently that they didn't pay too much for?


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## kaiserben (31/3/16)

I (and at least a few others, it seems) bought this and use it with the Tradeflame bottles from Bunnings. But another forum member warned against using something not made specifically for Oxygen, so use at your own risk. 

On another note, the way I inject O2 into my wort wastes a lot of oxygen and I'm wondering if I need the oxygen flowing for as long as I do it for: 

I store my stone and hose in no-rinse solution. 
I start the flow of oxygen while it's still in the no-rinse. 
I then move the stone/hose into the wort. 
When done I leave the oxygen flowing, take the stone/hose and dunk it in a sink of tap water (to clean the wort off it) and then take the stone/hose back into some no-rinse solution for storage, and finally turn the oxygen flow off. 
This way I don't need to boil it and it's always ready to use. 

I read somewhere about not wanting to get wort inside the stone, but do I really need to have the O2 flowing for that whole time? How does everyone else do it?


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## wereprawn (31/3/16)

Never used pure 02 myself but.....Is oxygenating the wort in place of a starter? If you've grown the correct amount of yeast, wouldn't you want it to metabolize anaerobically asap upon pitching into the wort , rather than continuing to multiply ?


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## GalBrew (31/3/16)

kaiserben said:


> I (and at least a few others, it seems) bought this and use it with the Tradeflame bottles from Bunnings. But another forum member warned against using something not made specifically for Oxygen, so use at your own risk.
> 
> On another note, the way I inject O2 into my wort wastes a lot of oxygen and I'm wondering if I need the oxygen flowing for as long as I do it for:
> 
> ...


I do it exactly the same way for the same reasons. I was also going through a lot of gas until I bought an oxygen flow meter off eBay. You can then keep the oxygen on but keep the flow to a minimum when transferring the stone. In general you will use a lot less oxygen when you can measure the flow.


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## MHB (31/3/16)

wereprawn said:


> Never used pure 02 myself but.....Is oxygenating the wort in place of a starter? If you've grown the correct amount of yeast, wouldn't you want it to metabolize anaerobically asap upon pitching into the wort , rather than continuing to multiply ?


Absolutely not!
While yeast is reproducing it is consuming Lipids and Protein from the wort, as well as the O2 we added and a bunch of other bits and pieces.
If you have the right sized starter (pitch) and the right amount of O2, in a well made wort it consumes all the stuff we don't want in the beer and the O2 at about the same time - the result is a large population of good healthy yeast that will not only ferment faster, will produce better beer and a much healthier more vital and viable yeast for repatching. 

Change any one of the parameters (O2, Nutrients...) and the result is lower quality beer and less healthy yeast.
So no the O2 doesn't replace a starter and the idea that yeast should go off like a hand grenade is wrong.
Mark


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## nosco (31/3/16)

Im getting the o2 setup fot lagers but when wouldnt you use it? I was thinking that people use it for lager wort and starters. I underpitched my first hefe as suggested in another post and i would have thought that using it for every ale would be a waiste of o2.


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## manticle (31/3/16)

It's more obvious in a pale lager or big beer when you omit things and pitch less than sufficient healthy yeast but all beers benefit from a good quality pitch.


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## SBOB (31/3/16)

is the bunnings 'Trade n Go' currently the most economical way to buy o2?

if so, what kind of regulator would fit it, anyone know?


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## MHB (31/3/16)

nosco said:


> Im getting the o2 setup fot lagers but when wouldnt you use it? I was thinking that people use it for lager wort and starters. I underpitched my first hefe as suggested in another post and i would have thought that using it for every ale would be a waiste of o2.


Again this is something of a misunderstanding. It is well known that if you pitch at the lower end of the recommended range a yeast will produce more flavor products, in the case of Hefeweizen more of the clove phenolic, banana and bubblegum that can make Hef so tasty.
That is very different to under-pitching, I and I suspect few home brewers are really pitching anywhere near the amount of yeast a commercial brewer would regard as adequate, to deliberately reduce the pitch rate further is not a good idea.

The right amount of O2 makes a big difference to your beer, this applies to all beers but the effect is more noticeable in some beers than others, same with yeast, there is a right amount and all the other amounts.
If you have O2 use it, only costs a little and can make all your beer taste better, the more so as we are all probably really under-pitching to start with.
I just wish good Dissolved O2 meters weren't so expensive.
Mark


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## Blind Dog (31/3/16)

whilst proper oxygenation with pure O2 seems to be advocated by many whose knowledge of the subject indicates they know what they're talking about, I know at least 2 award winning breweries that do no such thing, and aerate via spraying or agitation. Both have been around for a fair while and use a house yeast, so maybe their yeast has adapted to less than ideal conditions?

Personally, I aerate with an air pump, and it's fine for most ales - maybe not ideal, but no obvious off flavours and do pretty well in comps etc. Lagers, less so. An O2 system is definitely on my wish list, just need to persaude SWMBO that it should be on hers as well (and please no 'it's easier to ask for forgiveness than permission'. She's Catalan; there's no word for forgiveness in Catalan)


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## nosco (31/3/16)

I tried an air pump once but the air stone got blocked and it seems like alot of muckin about for something I could do with a paint stirrer and a drill. My lagers are a bit hit and miss so ill see how much o2 I use and then see about using it on ales.


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## nosco (31/3/16)

SBOB said:


> is the bunnings 'Trade n Go' currently the most economical way to buy o2?
> 
> if so, what kind of regulator would fit it, anyone know?





kaiserben said:


> I (and at least a few others, it seems) bought this and use it with the Tradeflame bottles from Bunnings. But another forum member warned against using something not made specifically for Oxygen, so use at your own risk.


I just ordered one of these SBOB so if it works ok Ill let you know.


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## Coalminer (1/4/16)

Interesting article with regards to O2 regarding new dry yeast and re-pitched dry yeast

http://www.danstaryeast.com/articles/oxygen-requirements


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## MHB (1/4/16)

Good read thanks
Mark


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## kaiserben (1/4/16)

wereprawn said:


> Never used pure 02 myself but.....Is oxygenating the wort in place of a starter? If you've grown the correct amount of yeast, wouldn't you want it to metabolize anaerobically asap upon pitching into the wort , rather than continuing to multiply ?


On top of what MHB said, 

If you're building a starter you're basically doing exactly what you'd be doing if you were pitching into wort. Any time you pitch yeast some cells die off, most multiply, some go dormant and over time more will die, but initially you end up with many more cells than you started with. Therefore pitching into a proper batch of beer sees your yeast population multiply - and if you've looked at making starters you'll know there is a relationship between the # of cells you start with and the volume of wort, which determines how many cells you end up with. 

So not only can you pitch the "correct" number of cells to begin with, but you can also create the best environment for them to multiply in as healthy a way as possible.


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## klangers (1/4/16)

You can aerate with oxygen

You can aerate with air, which is 20% oxygen. You just need more time/exposure. On a home brewing scale it's easy as piss to oxygenate sufficiently without oxygen - just go 5 times longer!

The main reason why pure oxygen might be perceived to perform better is that the comparisons with air have been carried out with air with impurities.

And like anything, as already mentioned, it is possible to over-oxygenate your wort.

Pure oxygen is incredibly reactive (ie dangerous). Using equipment not designed for oxygen use can result in corrosion and failure of the regulator. You do not want an oxygen bottle regulator failing around even mildly flammable materials.


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## kaiserben (1/4/16)

klangers said:


> it's easy as piss to oxygenate sufficiently without oxygen - just go 5 times longer!



My understanding is that the absolute most oxygen you can get into your wort by shaking (or using air, for example with an aquarium pump) is 8ppm. Shake it for as long as you want, but you won't get past 8ppm.


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## nosco (1/4/16)

Any one using nutrients as well as o2?


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## Mardoo (1/4/16)

Absolutely.


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## GalBrew (1/4/16)

As said above you can pump air into your wort until the cows come home but you won't get more than about 8ppm. Lagers in particular more than that, so the only way you bare going to get it is with pure oxygen.


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## Danscraftbeer (1/4/16)

nosco said:


> Any one using nutrients as well as o2?


I used a (drop) = 0.1g of nutrient in the starter with M07 for a Stout put down a week ago. 20lt I oxygenated the wort in a 30lt fermenter with a SS airstone moved around the wort gently so, lid on. Until the head filled the 10lt space. That was only about a minute I think. :chug: Unknown o2 level but then pitched the starter in and ferment was explosive!
Blown airlock and mess then blow off tube into a jar was worthy of video but I didn't bother. It could have run a small like steam engine or something.


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## nosco (1/4/16)

Ok im sold.


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## nosco (2/4/16)

Olive oil? Ok im joking before anyone replies.


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## Mardoo (2/4/16)

"It rubs the oil on its skin…"


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## nosco (5/4/16)

Ill stick with the lotion Mardoo.


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## Bribie G (11/5/16)

GalBrew said:


> As said above you can pump air into your wort until the cows come home but you won't get more than about 8ppm. Lagers in particular more than that, so the only way you bare going to get it is with pure oxygen.


That's why I've just bought an oxy kit as I've decided to do some proper lagers this year for the comps.

Running up a 5L batch of 1040 wort today with a stockpot BIAB and going to oxygenate each wort addition as I go.


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## Howlingdog (11/5/16)

What sort of oxy kit Bribie G?


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## DJ_L3ThAL (11/5/16)

Just for reference, I suggest even though the bottle are setup and handled 'differently', the grades of oxygen in terms of purity/cleanliness will be extremely similar if not identical. Reason being as I've raised before are oxygens super ability to support combustion of ANY materials. So 'suppliers' won't risk crap/contaminants getting into the oxygen to avoid law suits from hurting people or damaging equipment with exploding regulators or process machinery.

Use OXYGEN CLEAN AND COMPATIBLE equipment ONLY with oxygen, the hazards are real.


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## Bribie G (11/5/16)

HowlingDog said:


> What sort of oxy kit Bribie G?


Brewman's 

Should be here on Fastway today.


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## nosco (11/5/16)

Pitched a pils yesterday with s128 @9c. O2 for 60sec and yeast nutrient disolved in some cooled kettle water.
24hrs later @ 10.5c a nice 1cm thick krausen.


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## gezzanet (11/5/16)

Bribie G said:


> Brewman's
> 
> Should be here on Fastway today.


Got a brewman's O2 rig last Xmas also using nutrient in boil. Ferments seem a lot better as a result [emoji106][emoji106]


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## nosco (11/5/16)

I did chill the cube to 7c just to see how it would work but after trnfering to a fermenter and mucking about it had warmed up to 9c.


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## klangers (11/5/16)

GalBrew said:


> As said above you can pump air into your wort until the cows come home but you won't get more than about 8ppm. Lagers in particular more than that, so the only way you bare going to get it is with pure oxygen.


Mmm, my original post was overly simplistic. Certainly there are solubility limits which are affected by temperature, pressure and dissolved solids. Indeed, at a given ambient temperature and pressure, pure oxygen will dissolve roughly 5x more into a medium than oxygen in the air. The _rate_ at which the oxygen dissolves is a bit more complex to assess. My original point, which wasn't clearly articulated, is that up to this theoretical solubility limit, air works just as well.

Do we really need >8ppm? The only reason that I can think of is that you're under-pitching yeast, and it needs additional oxygen for the aerobic growth phase. I understand that it may assist with decreasing lag time, but I'm not sold on the concept as a one-size-fits-all approach especially in home brewing where I'm happy to wait a couple more days. To me it's cheaper and easier to prop my yeast up and aerate with air rather than frigging around with another yet another compressed gas cylinder etc.

Personally I don't like to add things to my brews that I can't measure. How do you know when you've added enough oxygen? It's not something you want to be pouring down the drain, so to speak. An ex-brewer (who happens to hold a brew master qualification) colleague at work said that it is entirely possible to _over_ aerate too, especially if you're looking for a particular yeast flavour profile. He could be full of shite, too. I don't know. 

Oxygen was only available rather recently in brewing history - how was aerating a lager done in early 1900s for example?

Not trying to be clever, but genuinely interested in the true science behind it all.


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## GalBrew (11/5/16)

In the Yeast book, there is a section on the ppm required for different ferments. Lagers in particular are recommended to have more than 8ppm (can remember what is was off the top of my head), which you cannot achieve with an air pump. Why can't we measure oxygen anyway? DO meters are available (albeit a little pricey), I have an oxygen flow meter, which while it does not measure the DO in the wort, it allows you to measure the volume of oxygen you inject into it (there are fudge figures correlating flow rates to ppm in the book too I believe) and while not the most accurate method of measurement it does allow for repeatability of process. It's also not that hard, it only takes a couple of minutes with the setup I have. I'm not sure where all the fuss about how 'difficult' it is comes from. If you don't want work for your beer I'm sure uncle Dan will hook you up with no work at all. 

I've also heard that is it possible to over do it with oxygen which is why I like the flow meter. 

Also there are many technological improvements that have been incorporated into brewing over the centuries, do you eschew things such as thermometers, hydrometers, pure yeast culture, hops etc.? If your aim is to emulate the brew of a medieval monk then fine, but why the issue with oxygen? If you don't want to use it thats fine, but you can't give the wort the recommended levels of oxygen for certain fermentations without it.


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## Bribie G (11/5/16)

Allsopp's lager brewery in London in the early 1900s fermented in closed glass-lined tanks under filtered sterile AIR pressure for the first part of the fermentation so that oxygen from the air would replace oxygen taken up by the wort. (edit, by the yeast).

Initial aeration was from wort run as a waterfall down arrays of chilled pipes into troughs where it flowed away into the fermenters.

The extra aeration could be done by opening the FV and thrashing with whisks or slotted spoons as I actually do for my Yorkshire Bitters but the O2 for me is a do once, set and forget method.

edit again: For my lagers I intend to quick chill in two lidded SS stockpots in tub full of ice water then pour into conical. That will be a smooth pour so there's going to be little agitation compared to my normal (for ales) glug and gloop transfer out of plastic cubes into FV, and way too little oxygenation.


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## klangers (11/5/16)

The difficulty comes from needing all the extra kit which needs maintenance and storage space which is an issue for those of us in units.

Whether it be intentional or not, It comes across in this thread as "pure oxygen is the only way you'll ever have success with lagers" which is demonstrably false. I'm not having a go at anyone, merely seeking to understand science rather than anecdotes.

A flowmeter, as you say, is a very rough approximation but gives repeatability. DO meters - yeah, maybe when I go pro 

I'm not attempting to not "work" for my brewing, I don't know where you got that from. I'm merely trying to understand why people are singing the praises of pure oxygen. 

No, obviously I don't eschew thermometers. That wasn't my question. I'm genuinely asking how it was done, not centuries ago, but even 40 years ago because I figured the yeast today is similar. However, the availability of oxygen was not the same then. On an industrial scale the cost of compressed oxygen would have been exorbitant back then and I highly doubt there isn't a workaround.

To reiterate - seeking to understand.

My underlying skepticism comes from trying to avoid "having to" get another bit of kit!


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## klangers (11/5/16)

Bribie G said:


> Allsopp's lager brewery in London in the early 1900s fermented in closed glass-lined tanks under filtered sterile AIR pressure for the first part of the fermentation so that oxygen from the air would replace oxygen taken up by the wort. (edit, by the yeast).
> 
> Initial aeration was from wort run as a waterfall down arrays of chilled pipes into troughs where it flowed away into the fermenters.
> 
> ...


Interesting . Thanks for the insight into The Old Brewery methods. It seems that they use the increased pressure to compensate for the reduced oxygen concentration in the air


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## MHB (11/5/16)

You don't have to use O2, but it is the simplest way to get consistent high quality beer within the confines of what we can do as home brewers. 
We tend to be under pitching, even those making starters are probably pitching at a fraction of what a commercial brewer would be using in a commercially made lager. A pitch 0.5L of heavy fresh yeast slurry per HL (100L) isn't atypical, that's something like the equivalent of 64 fresh smack packs or tubes of the two best know liquid cultures into 20L of home brew - if anyone is doing anything like that at home, well they would be the only one.

Having an acceptable pitch into a wort with the optimum amount of O2 will (this has been ignored said earlier) mean that as the yeast reproduces, and it does that until it runs out of one essential nutrient it will consume all (or most) of the undesirable wort constituents (mostly lipids and fatty acids), resulting in better attenuated more stable and enjoyable beer.

I don't see anything in Bribes post that says there was any pressure involved, bottled Oxygen has been available a lot longer than you might think, Oxy cutters invented in 1901 were widely in use in ship construction by the start of WW1 that's over 100 years ago, I suspect brewers were on to bottled oxygen PDQ as they tend to have been hot beds of technical innovation.

DO meters are out of many brewers price range, the easiest way to get a very close to target amount is to measure the temperature of the wort, over oxygenate slightly and wait 5-10 minutes before pitching. Solubility is temperature dependant and will quickly fall back to that value at any given temperature
ppm of O2 in 12oP (1.048) wort (temp/ppm of O2) 0oC/11.6; 5oC/10.4; 10oC/9.3; 15oC/8.3; 20oC/7.4
From there you can interpolate how much O2 you will have in your wort, quite accurately.

It would be easy to spend several hours extoling the virtues of O2, you can spend as long as you like finding reasons not to spend the money, just don't pretend its to make better beer.
Mark


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## GalBrew (11/5/16)

klangers said:


> The difficulty comes from needing all the extra kit which needs maintenance and storage space which is an issue for those of us in units.
> 
> Whether it be intentional or not, It comes across in this thread as "pure oxygen is the only way you'll ever have success with lagers" which is demonstrably false. I'm not having a go at anyone, merely seeking to understand science rather than anecdotes.
> 
> ...


I'm sure you can do a good lager without oxygen too. I personally like to pitch a lot more yeast in my lagers also, which no doubt helps more than the oxygen. You seriously don't need that much kit to use oxygen, though, the most annoying thing is the cost of the bottles. 

Anyhow I'm not sure what brewers did historically. We only discovered yeast relatively recently, so I would guess that they did nothing as they had no idea how to improve yeast metabolism.


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## klangers (11/5/16)

Colour me convinced!


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## Frothy1 (11/5/16)

Ive been told the white Tradeflame bottles last longer than the black ones.

http://www.bunnings.com.au/tradeflame-930ml-oxygen-gas-cartridge_p5910241



And the reg has the meter on it.

http://www.ebay.com.au/itm/Disposable-Gas-Bottle-Regulator-Argon-CO2-Bossweld-600044-/111359555038?



Dont know if the 0.5 micron is better or not.

http://www.ebay.com.au/itm/Diffusion-Stone-Air-Stone-2-0-Micron-Stainless-Steel-Home-Brew-005298-/271407244742?


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## Bribie G (11/5/16)

Aha I got it wrong about the top pressure at the old Allsopps brewery:


_It is a sign of the times and further evidence as to the growing taste for a lighter type of beer, that lager brewing in its most modern form has now fairly taken root in Great Britain, and in this connexion the process introduced by Messrs Allsopp exhibits many features of interest. The following is a brief description of the plant and the methods employed:—The wort is prepared on infusion lines, and is then cooled by means of refrigerated brine before passing to a temporary store tank, which serves as a gauging vessel. From the latter the wort passes directly to the fermenting tuns, huge closed cylindrical vessels made of sheet-steel and coated with glass enamel. There the wort ferments under reduced pressure, the carbonic acid generated being removed by means of a vacuum pump, and the gas thus withdrawn is replaced by the introduction of cool sterilized air. The fermenting cellars are kept at 40° F. The yeast employed is a pure culture (see Fermentation) bottom yeast, but the withdrawal of the products of yeast metabolism and the constant supply of pure fresh air cause the fermentation to proceed far more rapidly than is the case with lager beer brewed on ordinary lines. It is, in fact, finished in about six days. Thereupon the air-supply is cut off, the green beer again cooled to 40° F. and then conveyed by means of filtered air pressure to the store tanks, where secondary fermentation, lasting three weeks, takes place. The gases evolved are allowed to collect under pressure, so that the beer is thoroughly charged with the carbonic acid necessary to give it condition. Finally the beer is again cooled, filtered, racked and bottled, the whole of these operations taking place under counter pressure, so that no gas can escape; indeed, from the time the wort leaves the copper to the moment when it is bottled in the shape of beer, it does not come into contact with the outer air._


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## klangers (12/5/16)

Frothy1 said:


> Ive been told the white Tradeflame bottles last longer than the black ones.
> 
> http://www.bunnings.com.au/tradeflame-930ml-oxygen-gas-cartridge_p5910241
> 
> ...


Give this man a beer. A good succinct post with all the info one needs. Had this been posted earlier, I suspect this thread could have been stopped at 2 pages!


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## MHB (12/5/16)

On Air Stones, I have tried both and use a 2um.
The 0.5um are very easy to block up, even touching it with your fingers is sometimes enough. They are so fine that when you soak them in sanitiser it doesn't penetrate into the fine pores (surface tension). The size of the bubbles from both and the rate that wort aerates is nearly the same.

I just find the 2um stones a lot easier to look after and last longer before needing replacing.

Bubble formation is interesting, as a gas flows through the pore a small bubble starts to inflate, surface tension holds it in place until it becomes big enough and buoyant enough to detach and float away. Point is it isn't really the size of the hole that determines the size of the bubble, it has a lot more to do with the density the surface tension of the liquid and the overpressure (height of liquid over the stone).
About the smallest bubble you can see is 0.5mm and you can see the bubbles that form on both stones.
Mark


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## mstrelan (12/5/16)

Frothy1 said:


> And the reg has the meter on it.
> 
> http://www.ebay.com.au/itm/Disposable-Gas-Bottle-Regulator-Argon-CO2-Bossweld-600044-/111359555038?


Is this suitable for use with O2?


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## klangers (12/5/16)

Good point.

Probably not. Argon/helium/CO2/Nitrogen are all chemically stable and hence the regulators are all generally interchangeable. O2 is obviously not stable and often requires higher grade materials, so you risk the regulator slowly oxidising and failing.


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## Frothy1 (12/5/16)

mstrelan said:


> Is this suitable for use with O2?


It will do for my application.

They sell the kit.
http://www.ebay.com.au/itm/Disposable-Gas-Bottle-PURE-OXYGEN-1x-l-litre-Bottle-Combo-Oxy-LPG-Acet-600037-/111621305999?hash=item19fd25f68f:g:6vQAAOSwNSxVBDVC


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## Mikeyr (12/5/16)

Frothy1 said:


> It will do for my application.
> 
> They sell the kit.
> http://www.ebay.com.au/itm/Disposable-Gas-Bottle-PURE-OXYGEN-1x-l-litre-Bottle-Combo-Oxy-LPG-Acet-600037-/111621305999?hash=item19fd25f68f:g:6vQAAOSwNSxVBDVC


 That seems damn cheap, did you see these in the footer

http://www.ebay.com.au/itm/LZQ1-7-Oxygen-Flowmeter-Flow-Meter-Control-Valve-0-25LPM-for-Air-Gas-Conectrator/131567346784?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140117125611%26meid%3De170be4d27114b5ca671c26b2ab85db9%26pid%3D100009%26rk%3D6%26rkt%3D10%26sd%3D111621305999


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## mofox1 (12/5/16)

Frothy1 said:


> They sell the kit.
> http://www.ebay.com.au/itm/Disposable-Gas-Bottle-PURE-OXYGEN-1x-l-litre-Bottle-Combo-Oxy-LPG-Acet-600037-/111621305999?hash=item19fd25f68f:g:6vQAAOSwNSxVBDVC





Mikeyr said:


> That seems damn cheap


Frothy - that's awesome. I've already got an air stone I don't use (the little acq pump I bought never had enough oompf to get it to work), so this kit plus a little bit of beer line would be all I need. Could add in a dip tube as a gas wand...

Agreed Mikeyr, that's the best deal I seen. Does anyone know how long it would take to go through 110L of O2? It **sounds** like a lot... :unsure: ??

Happy to hear others opinions on the suitability of the regulator - would seem odd if they are selling it as a kit and the reg is not suitable of O2.


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## DJ_L3ThAL (12/5/16)

Depends if the 110L is at standard temp and pressure or at the supply pressure of 600kPa.


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## Black n Tan (12/5/16)

mofox1 said:


> Agreed Mikeyr, that's the best deal I seen. Does anyone know how long it would take to go through 110L of O2? It **sounds** like a lot... :unsure: ??


The typical does rate is 1L/min for 1 min for 23L batch, so 1L per batch. So enough for 110 batches, but you will have losses so would think you should get at least 70-80 batches out of it.


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## Bribie G (12/5/16)

The Italian cylinders ex Brewman hold around 95L gas volume.


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## mofox1 (12/5/16)

Black n Tan said:


> The typical does rate is 1L/min for 1 min for 23L batch, so 1L per batch. So enough for 110 batches, but you will have losses so would think you should get at least 70-80 batches out of it.


Cheers B&T, that's probably close to 3 years worth (for me) - although probably less if I use it on my starters too. At 50 to 60 bucks for a new bottle it's not too bad cost wise.


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## Black n Tan (12/5/16)

It will make a big improvement to your beers and after the initial outlay is quite economical.


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## mofox1 (12/5/16)

Black n Tan said:


> It will make a big improvement to your beers and after the initial outlay is quite economical.


Just like the rest of the hobby, huh?


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## DJ_L3ThAL (12/5/16)

I'm interested to know two things:


Do these flow meters coming with the kits/regulators quote L/min in standard temperature and pressure units, or do they quote that as volumetric flow (ie. more *actual* Oxygen is going through than what is read).

e.g. Oxygen dispensed at a volumetric rate of 1L/min @ 6 bar.g pressure would mean you're actually dispensing approx 6 L/min (roughly every bar pressure requires another "volume" of gas mass. So these cylinders may not last the length one would expect calculating the 1 L/min being dispensed in true S.T.P units.

Are the Tradeflame cylinders at Bunnings etc compatible with this 10mm thread on the Sealey type regulators?

Side note I looked at Sealey's site and they are not designed for use with Oxygen (Only quotes CO2/Argon use) so use at your own risk. I can't find any small/cheap Oxygen regulators probably because the Oxygen cleaning would cost more than the entire value and make them too expensive.


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## Benn (12/5/16)

Apparently Keg King have a complete O2 kit coming soon, pretty sure it's designed to run off the small O2 cylinders available off the shelf at Bunnings etc. 
I could be mistaken, the conversation was a few weeks ago and I was in that strange state that one enters when they walk around and around a HB Shop with money to spend, no shopping list and nothing particularly needed for the brewery on the day.


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## klangers (13/5/16)

DJ_L3ThAL said:


> I'm interested to know two things:
> 
> 
> Do these flow meters coming with the kits/regulators quote L/min in standard temperature and pressure units, or do they quote that as volumetric flow (ie. more *actual* Oxygen is going through than what is read).
> ...


They are quoting volumetric flow rate. Since the pressure is just the back pressure of the airstone, tube and then the hydrostatic pressure of the immersion in the wort, the total pressure will be pretty close to atmospheric (standard)


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## DJ_L3ThAL (13/5/16)

Completely agree that by the time the O2 makes its way through the stone into the wort it would be near atmospheric. The measurement value is in the flowmeter though, so there is a restriction across the tube and float which is typically calibrated for a certain supply pressure. You don't have atmospheric at the regulator outlet before the flow meter, I also don't think they look restrictive enough to drop the pressure from 6 bar.g to atmospheric 0 bar.g, because that in itself would infer a pretty decent flow, far above 3L/min (S.T.P).

The info on the equipment is not clear as to whether we can simply say a 110L O2 bottle will last 110minutes if running the flow meter at 1L/min flow. As the pressure of the gas will mean more O2 is going through and the bottle won't last as long. Trying to ensure some people don't run off and end up dosing at 6L/min (S.T.P) whilst thinking they are dosing 1L/min and poisoning their yeast because they are not understanding how a gas flow meter works.


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## mofox1 (13/5/16)

Agree Nath, that "flow meter" could just be a bit of toss. I'd be better off getting a float flow meter...


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## Crusty (19/9/16)

I'm just curious as to what lag time you guys are getting before active fermentation if using an airlock & pressurized O2.
I used mine for the first time yesterday on a 50L batch of a 150 Lashes clone. I ran it for 90sec which I thought would be ample.
I planned to check on it every hour to gauge when fermentation kicked in. After the first hour, I noticed that pressure was building in the airlock & I got activity probably every 3-5 mins or so. I was initially impressed assuming that it's going to go gangbusters after a few hours. It stayed this way for the next 12hrs or so & it didn't really get a move on until about 15hrs into it. It's now 24hrs after pitching & it's really cranking along with a bloop every 5sec or so. I thought that adding the O2 should have reduced my lag time but it seems to be a similar time frame. I pitched a healthy stepped starter so had ample yeast for this batch.


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## malt junkie (19/9/16)

You'll find around 3-4 hours after you initial hit of O2 the yeast will have eaten it all up, and for big beers a second hit around the 4-6 hr mark will really get it kicking. Note all this assumes a good healthy pitch of yeast etc. Oxygenation is mainly about increasing numbers.

Remember our craft and mega swill brewers pitch a ton load more yeast than we do and they still oxygenate.


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## DJ_L3ThAL (19/9/16)

Crusty, O2'ed a batch last night at 7PM. Same as you within 3 hours I was thinking whoa, there is positive pressure in the blow off (by lifting the hose slightly caused some bubbles suggesting it just hadn't overcome the sanitizer liquid column. In the morning at 7am I checked when I got up and no activity. Came home tonight at 6pm and it was bubbling every 1 second which is high Krausen. Which is more than acceptable but doesn't seem "faster" than a normal healthy pitch, although I don't O2 for speed of ferment, more for yeast health and ensuring well maintained fermentation.

I concluded that perhaps given the aforementioned solubility rates, perhaps the O2 coming out of solution builds some slight pressure and gives the indication there is yeast activity where really it's just the wort dropping back to it's solubility of O2 at the given temp.

Thoughts?


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## Lyrebird_Cycles (19/9/16)

malt junkie said:


> You'll find around 3-4 hours after you initial hit of O2 the yeast will have eaten it all up, and for big beers a second hit around the 4-6 hr mark will really get it kicking. Note all this assumes a good healthy pitch of yeast etc. Oxygenation is mainly about increasing numbers.
> 
> Remember our craft and mega swill brewers pitch a ton load more yeast than we do and they still oxygenate.


The more yeast present the more O2 will be needed as they will need to synthesise more cell wall lipids to stay healthy.

I think there is some confusion in the HB community over what O2 does.

Adding O2 helps yeast adapt to growth in the inhospitable anaerobic environment that is a fermenting wort. We don't usually add enough O2 to promote aerobic (respiratory) growth rates.

Oxygen is used to make lipids and the lipids are required for growth, so oxygen will promote growth but there's a lag while the yeast use the oxygen to make the lipids they need.

The other benefit of O2 is at the back end of fermentation: having a healthy cell wall allows the yeast to stay alive in the presence of a toxin (alcohol) which primarily works by knocking chunks out of the lipid bilayer and causing the contents of the cell to leak.

BTW that's also how alcohol works in your brain and liver: it makes the cells slightly leaky. Brain cells change the way they talk to each other, liver cells change the way they sieve fats out of the bloodstream.


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## Crusty (19/9/16)

So basically I too misunderstood the benefits of using O2. If we pitch a good healthy starter with sufficient yeast cells, adding O2 simply gives the yeast more oxygen to use to multiply which in turn builds up their numbers. They can simply reproduce in the presence of oxygen & once those levels drop, active fermentation begins. Shorter lag times shouldnt be expected then? Once fermentation begins, it should be more aggressive & may finish earlier than a non oxygenated wort but will have the benefit of a stronger cleaner ferment?
Am I on the right track here?


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## Lyrebird_Cycles (19/9/16)

DJ_L3ThAL said:


> I concluded that perhaps given the aforementioned solubility rates, perhaps the O2 coming out of solution builds some slight pressure and gives the indication there is yeast activity where really it's just the wort dropping back to it's solubility of O2 at the given temp.
> 
> Thoughts?


I don't think that would be the case, as far as I am aware almost all the O2 that goes into solution is absorbed by either oxidation reactions in the wort or taken up by the yeast. I cannot see the solubility equilibrium shifting to release oxygen that was already in solution.


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## peteru (19/9/16)

Crusty said:


> adding O2 simply gives the yeast more oxygen to use to multiply which in turn builds up their numbers.
> ...
> Am I on the right track here?


I don't think so. I think the point is that the yeast will multiply regardless of the oxygen level. More O2 will make the yeast more healthy, which means that they will not die as quickly and more importantly their metabolism will be healthier, thus resulting in fewer fusel alcohols and other off-flavours.


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## Lyrebird_Cycles (19/9/16)

Crusty, Peteru, I steered you wrong in the first version of post #109 by not clarifying the effect of oxygen on lipids and the subsequent effect on growth. My apologies, I've corrected it now.


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## peteru (20/9/16)

Right. That bit about lipids now also makes more sense in the context of trying to introduce fatty acids so that the yeast doesn't have to do as much work on that task.


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