Pure O2 Equipment

[Jocky]

Every now and then a discussion over the kit required for pure O2 aeration comes up in a thread, but when researching it myself I've found the information hard to piece together, so I thought I'd put up a topic to discuss the subject and document what I'm doing so hopefully the next person doesn't have to struggle the same way.

Before we start though:

WORKING WITH PURE OXYGEN CAN BE DANGEROUS AS IT PRESENTS A FIRE RISK. ALWAYS WORK OUTSIDE. NEVER WORK NEAR ANY SOURCE OF IGNITION.

In particular: people who have been exposed to an oxygen-enriched atmosphere must not smoke or go near naked flames or sparks until they have properly ventilated their clothes in a normal atmosphere. A ventilation period of 5 minutes minimum, with movement of the arms and legs and with coats unbuttoned, is recommended.


The widely repeated but not necessarily proven 'ideal' for pure O2 aeration is for a 5 gallon/~20 litre batch to provide 1 minute of oxygen at a rate of 1 litre/minute in order to hit 12ppm of dissolved oxygen. Some yeasts and beers will need more, some less.

These are the things that you will need for pure oxygenation:

• Pure Oxygen bottle
  Regulator that fits oxygen bottle
  Aeration stone
  (Optional) Flow meter
  Gas hoses and connectors to put it all together
  A stand for the oxygen bottle (to keep it upright)

I'll post up everything about each item in turn

[Jocky]

UPDATE: I've updated this post to cover my setup as of 2018...


Pure Oxygen tank/bottle
Starting with the obvious you need pure O2. The only readily available supply of this seems to come from welding supply shops.

http://welduk.com/product/oxyturbo-4803 ... s-cylinder

Now you may be wondering if this is 'food grade'. Having hunted around a bit, including on a private pilots forum where they were wondering about sources of oxygen bottles for higher altitude flight, the consensus seems to be that all the pure oxygen comes from the same source, whether welding or medical. The difference is mainly down to the sanitary nature of fittings in the packaging and certification for medical use.

You can either get bigger refillable bottles for oxygen, or smaller 'disposable' bottles.

I'm only looking at disposables here as a disposable will cost about £25 for a 1 litre bottle of oxygen at 110 bar, which is equivalent to about 108 litres of oxygen at atmospheric pressure. As I only need 1 litre of oxygen per batch a disposable is going to keep me going for quite a long time.

A refillable bottle is going to be 9 or more litres and enough to keep me going for 15 years - so perhaps more appropriate for a semi-pro or pro setup.

So I have an oxyturbo cylinder as linked to above.

Regulator
Each type of bottle (and even each different manufacturer of disposable bottle) seems to need a different regulator.

I purchased the appropriate regulator for the Oxyturbo cylinder at the same time. This one: http://welduk.com/product/regulator-dis ... n-cylinder
It has a stupid little barb on it that I removed and replaced with a JG fitting, but found that it leaked after a while.

I have since moved to a regulator from the same company with a gauge and a proper screw on fitting for the gas line rather than a barb: http://welduk.com/product/regulator-gau ... n-cylinder
You can screw a JG 3/8" bsp to 3/8" push fit fitting straight on, it doesn't leak, and the gauge tells you when you're running out of oxygen. Much better!

Flow Meter
Most of the options for flow meters are for measuring way more than 1 litre per minute.
There are two options that can measure a lower flow rate.

Cole Parmer sells one for just over £20, but with their delivery charge you'll be close to £30 once done:
http://www.coleparmer.co.uk/Product/Poc ... Y-32500-80
Anecdotal comments have said that it's very expensive for what you get. I have not seen any comments on accuracy (I'd hope at that price there would have been some calibration!)

The other option is an LZQ oxygen flow meter that you can find on ebay. I started off with one that measures 0-3 litres per minute, and then changed to one that measures 0-1.5 litres. Both were a few pounds delivered, and when checking accuracy they were close enough.

It has metal barbs to connect to that seems to be a good fit for 3/8" gas/beer line or you can screw on JG fittings.

If you want to check the accuracy of your flow meter, then this video shows a useful method of inverting a measuring cylinder over the top of your hose/air stone: https://www.youtube.com/watch?v=lOMjYHh7lwE

Air Stone
The final choice on equipment is the air stone. You can get them in steel or ceramic, and with 0.5 or 2 micron holes.
0.5 micron should ensure better oxygen transfer so I'd recommend that.
I went with a stainless steel wand from Brew Builder to make the whole thing easier to handle, particularly when keeping the stone submerged while oxygenating wort.

https://www.brewbuilder.co.uk/air-stone-wand.html

Before and after use I boil the end of the wand in a solution of citric acid to avoid crud build up and scale. I also wrap it in cling film to avoid getting anything on it or touching the stone end.

Gas line and fittings
To fit the whole thing together I used:
- JG 3/8" bsp female to 3/8" push fit (on the regulator)
- 3/8" beer/gas line (pushed onto flow meter barbs)
- JG 3/8" to 3/16" inline reducer to connect the beer line to the aeration wand.

[BenB]

Great idea- I can see this becoming a sticky. Refillable bottles have the added disadvantage of being heavy and they won't refill them unless they've recently been "tested" , which just adds to the costs. I've got a refillable (got it free from work) but it is a pain to lug around and when I asked how much it would cost to get it refilled most places don't want to know. Nowhere local either and Royal Mail don't take gas bottles (even when empty) so that means a courier... So disposable wins I think.

Main issue I had with oxygen was getting a system that didn't leak under the high pressures required of a 0.5 stone. Also a lot of flow meters aren't designed to take those pressures ? fragmentation risk.

[Matt in Birdham]

I'll throw my 2c worth up, as I have just put together a similar rig.

The issue I had was that I also got the "default" regulator with the tiny barb. A 3/16 beer line -> JG reducer -> 3/8 beer line works OK, but is a little clumsy looking. 6mm ID silicon zip tied over the 3/8 seems secure enough.

I bought an ebay cheapy flow meter, which (seems to) work fine when there is no back pressure, but is basically useless once the 0.5 micron stone is added. Having subsequently read a bit on the US forums, it seems like most people aren't even using flow meters and that there is some evidence that flow rate is not critical - instead the time is important. I don't know how true that is, but for my second brew with this rig I just removed the flow-meter and eyeballed "bubbles just breaking the surface" for 60 seconds, which is what seems to be recommended most often. I'd like to measure actual flow rate one day using an inverted funnel and measuring cylinder, so that I at least have a rough idea of what 2l per minute looks like in a jug of starsan, say. So for me at least, a simpler setup of just going straight from the bottle to the stone via 6mm silicon seems to work (I also tried making a "wand" from a length of stainless tube, but had issues with the connections popping off under pressure, and in any case the silicon is soft enough to let the stone drop to the bottom of the FV without issue).

[Rhodesy]

Really liking a one stop topic for this. I have been looking into this myself as I look to upgrade and progress with my set up. Does anyone have pics of their set up they can share?

[McMullan]

Timely post. I've just got in the bits and pieces for oxygenating higher gravity beers. I went for the disposable 'Oxyturbo' set up:

[barneey]

The rule of thumb for pure O2 aeration is for a 5 gallon/~20 litre batch to provide 1 minute of oxygen at a rate of 1 litre/minute. Some yeasts and beers will need more, some less.

Can I ask where the rule of thumb is from?

[Goulders]

There's quite a bit on the internet about "rule of thumb" (eg BYO magazine), however, the one minute is for higher gravity beers and about 30s for lower gravity. I recently invested in the oxyturbo setup, but you want to aim for small bubbles gently breaking the surface, not a "rolling boil"!

[Jocky]

The rule of thumb for pure O2 aeration is for a 5 gallon/~20 litre batch to provide 1 minute of oxygen at a rate of 1 litre/minute. Some yeasts and beers will need more, some less.

Can I ask where the rule of thumb is from?

Just about everywhere I've looked to try and get a handle on how much oxygen to use. If there's a better rule that doesn't involve a DO metre I'll happily update the above.

Wyeast says 12ppm is with 60 seconds of pure O2 here https://www.wyeastlab.com/hb_oxygenation.cfm

[barneey]

The rule of thumb for pure O2 aeration is for a 5 gallon/~20 litre batch to provide 1 minute of oxygen at a rate of 1 litre/minute. Some yeasts and beers will need more, some less.

Can I ask where the rule of thumb is from?

Just about everywhere I've looked to try and get a handle on how much oxygen to use. If there's a better rule that doesn't involve a DO metre I'll happily update the above.

Wyeast says 12ppm is with 60 seconds of pure O2 here https://www.wyeastlab.com/hb_oxygenation.cfm

Not saying its wrong but I think most of the info stems from one source, that being the yeast book. With my experiments "in water" with a DO meter a lot longer time is needed. There is also the case of using a stone, which needs to be clean and kept clean, when you bubbler o2 through a FV most of the o2 IMO ends up going through and if a lid isn't attached gets wasted, are the internet figures for an open or closed container & what sized stone?

My current procedure is to blow o2 through a port on the side of a FV, same could be done with a length of hose dangled into the FV, I keep the lid on while doing this so the free area above the wort fills with o2 / exchange. Another train of thought is introduce the o2 in the pipework that fills the FV, bubbling o2 through a pipe filled with wort is surely more effective.

[McMullan]

Traditionally, sufficient oxygenation was achieved during transfer of cooled wort to the FV. I have always relied on that plus rolling the FV (wort) back and forth for a minute or so. It works fine. Primary fermentation is complete within 3-5 days. What I have noticed with bigger beers is a drop in fermentation performance, which usually ends short of expected attenuation. So it will be interesting to try pure O2. Like barneey, I haven't been able find any real data to guide what levels are optimal. Probably because none exist. As usual, it's something we would have to determine empirically in our own set ups and brews. O2 solubility in wort decreases as gravity increases. Similarly, O2 solubility decreases as wort temperature increases. For a for a really big beer, is it worth oxygenation wort below pitching temperature, for more than a minute?

[orlando]

My set up uses a flow meter (medical) and I usually go for 1 to 1.5 minutes in 25-30 litres, depending on whether the yeast is one that likes a lot or not, based an anecdote.I pump the wort into the conical and it splashes quite a lot as it hits the cooling coil so there is already some oxygenation before I start. In the picture you can just see that the airstone is placed within a fitting that tri-clamps into the dump valve. I open the valve and start the O2 and start timing. Despite having a DO meter I haven't yet measured this method but did experiments with water last year and found the "rule of thumb" was not far out in getting water to the circa 10-12 ppm, but this was water, wort might be different. An experiment for the long dark days of Winter perhaps.

[Jocky]

The rule of thumb for pure O2 aeration is for a 5 gallon/~20 litre batch to provide 1 minute of oxygen at a rate of 1 litre/minute. Some yeasts and beers will need more, some less.

Not saying its wrong but I think most of the info stems from one source, that being the yeast book. With my experiments "in water" with a DO meter a lot longer time is needed.

Fair enough - I think I'm probably influenced by the many faces of Jamil Zainasheff. At the end of the day I created this topic to try and pull together all the actual knowledge/experience out there in the use of Pure O2, so I'm more than happy to have any assertion I've made challenged.

I managed to nab a DO meter cheap off an auction site so I will do some experimentation myself.

[Jocky]

Here's my latest update - I've added it to the top posts:


Flow Meter
Most of the options for flow meters are for measuring way more than 1 litre per minute.
There are two options that can measure a lower flow rate.

Cole Parmer sells one for just over £20, but with their delivery charge you'll be close to £30 once done:
http://www.coleparmer.co.uk/Product/Poc ... Y-32500-80
Anecdotal comments have said that it's very expensive for what you get. I have not seen any comments on accuracy (I'd hope at that price there would have been some calibration!)

The other option is the LZQ-2 oxygen flow meter that you can find on ebay that measures 0-3 litres per minute. I got mine for £6 delivered, and plan to check its accuracy in the near future.
It has plastic barbs to connect to, that seems to be a good fit for 3/8" gas/beer line.

If you want to check the accuracy of your flow meter, then this video shows a useful method of inverting a measuring cylinder over the top of your hose/air stone: https://www.youtube.com/watch?v=lOMjYHh7lwE
I will conduct this myself shortly to gauge the accuracy of my flow meter.

[Jocky]

Air Stone
The final choice on equipment is the air stone. You can get them in steel or ceramic, and with 0.5 or 2 micron holes.
0.5 micron should ensure better oxygen transfer so I'd recommend that.
I went with a stainless steel wand from Brew Builder to make the whole thing easier to handle, particularly when keeping the stone submerged while oxygenating wort.

https://www.brewbuilder.co.uk/air-stone-wand.html

Hooking it all up
I've seen a few messy setups, using cable ties and fitting tube over tube. In the end thanks to a hint from Mr Lard at Brew Builder I found a lovely solution that doesn't leak at all, using some 3/8" gas line and two John Guest fittings.

You will need:

3/8" gas/beer line - 2 metres ish
John Guest Speedfit 3/8" to MFL 1/4" (I have only seen these at Brew UK https://www.brewuk.co.uk/john-guest-3-8-1-4mfl.html)
John Guest Speedfit Reducer 3/8 - 3/16 (https://www.brewuk.co.uk/john-guest-reducer-3-16.html)

The MFL Connector is so that you don't have to use the stupid barb on the regulator.

Unscrew the barb from the regulator. You will find the following bits inside it, which I believe are a flashback arrestor. Very useful safety feature when welding, not so much for us.
Take the rubber seal off the barb and put it aside. The barb and other bits from the arrestor you can throw away.

Now take your MFL fitting and cut off the flared end so you only have thread left (I used a junior hack saw, but a sharp stanley would work too). Fit the rubber seal you saved from the barb over the thread and then screw it in gently to the regulator to check the fit.
I ended up taking a bit more of the mfl threads off too to get a good seal.

And tada, you now have a regulator with a 3/8" gas line output.

Now you're ready to assemble your oxygen rig.

Quite simply you need to run gas line from the regulator to your flow meter and then flow meter to the JG reducer, with the reducer fitting on the end of the aeration wand. And you're done:

I'd really recommend making a stand for your gas bottle so you don't end up shooting liquid oxygen out the regulator. I made mine out of some left over pieces of slotted angle.
(EDIT: Apparently the O2 is not in liquid form, just very compressed, so this shouldn't be an issue. I'm still pretty certain the gas bottle still says to keep upright, but I have seen someone else with one mounted horizontally and no problem, so who knows. I'd suggest sticking with the safety notice)


I found that the barbs on the flow meter fit the gas line nice and snugly. Even when I closed the flow meter valve and opened the gas bottle reg to pressurise the connection everything stayed together - a little soapy water on the connection showed the slightest of leaks, but it was really very very slight.

After putting everything together I tested the flow meter rate and found that it was roughly accurate - at 1 LPM it filled an inverted 100ml cylinder of water in just over 6 seconds.