Mixed gas

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Alexdc12
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Mixed gas

Post by Alexdc12 » Fri Jul 13, 2018 2:48 pm

Hi all
So I have a keg of amstel and was serving t via a cornelius maxi 110 cooler with the use of some 30/70 gas. All was well once I got a secondary regulator but now my lager has become flat. Upon investigation I should have been using 60/40 mixed gas. Will simply switching to 60/40 rectify the issue? I don't want to waste about 6gallons of lager!
Tia

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PeeBee
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Re: Mixed gas

Post by PeeBee » Fri Jul 13, 2018 3:32 pm

You've probably misunderstood what mixed gas is for. Its most basic use is to drive beer along very long lengths of beer-line using the sort of high pressures that, if using just CO2, would deliver a glass of froth. More carefully it can be used with high pressure, special tap "sparklers" (restrictor plates) and frigid temperatures to create creamy heads, yet not dissolve huge quantities of CO2 in the beer (CO2 creates carbonic acid which doesn't result in a "smooth" flavour).

So what you've done is used, say for example, 10PSI of pressure which according to the rules of "partial pressure" is the same as using 3PSI of CO2 (30/70 gas is 30% CO2, 70% of N2) which creates carbonation just a bit more than "Real Ale". It's not flat, just very under carbonated for lager.

So forget 60/40 gas (60% CO2 - getting it?) and get pure CO2. Release all the pressure in the keg (by whatever means is safe) - this gas is mostly Nitrogen and you don't want that - and re-pressure with pure CO2. Optionally repeat next day (to purge out more N2). Keep the keg cold and keep the pressure topped up (the lager will be absorbing the CO2) and in … (a few days or however long, I don't know - I don't like keg beer!) … the beer will reabsorb CO2 ("force carbonate").
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

Alexdc12
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Re: Mixed gas

Post by Alexdc12 » Fri Jul 13, 2018 4:28 pm

Hi peebee

Makes sense! So I belive I need a different fitting for co2?
Also how can I release the pressure currently in the keg?
Thanks

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LeeH
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Mixed gas

Post by LeeH » Fri Jul 13, 2018 4:49 pm

PeeBee has nailed it. Mixed gas for stouts or long runs.

Yes you need a new reg to fit a CO2 bottle.

What keg have you got?


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Alexdc12
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Re: Mixed gas

Post by Alexdc12 » Fri Jul 13, 2018 4:57 pm

Would it be as simple as using a brass coupler to convert male to female

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Re: Mixed gas

Post by PeeBee » Fri Jul 13, 2018 6:18 pm

Ah yes, sorry, CO2 cylinders have a different and male thread to avoid accidents. I doubt you'll easily find an adapter, the threads are quite kooky. You could get 60/40 (it is a compressed gas so could be at 3000PSI - CO2 is a liquid at about 8-900PSI) just remember you will need a higher pressure to get the carbonation you want.

For example. If you want the carbonation of, say, 10PSI you'd need 10 + 10/60*40 or 16.6PSI of 60/40 mixed gas for the same carbonation. Your tap might splutter a bit. To get decent (or should that be indecent?) amount of nitrogen to start dissolving you need 30+PSI (and a bomb shelter?).
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

Alexdc12
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Posts: 45
Joined: Tue May 29, 2018 7:52 pm
Location: Essex

Re: Mixed gas

Post by Alexdc12 » Fri Jul 13, 2018 7:13 pm

LeeH wrote:
Fri Jul 13, 2018 4:49 pm
PeeBee has nailed it. Mixed gas for stouts or long runs.

Yes you need a new reg to fit a CO2 bottle.

What keg have you got?


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Pictures attached. So do I need to replace the primary regulator too?

Would it not be easier to just switch to 60/40?
Attachments
_20180713_191042.JPG
Secondary reg
_20180713_191016.JPG
Primary regulator
_20180713_190940.JPG
Keg

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PeeBee
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Re: Mixed gas

Post by PeeBee » Fri Jul 13, 2018 7:45 pm

Flippin' "504 Gateway timeout". I'm sure Jim will sort it in a bit. Still, managed a screenshot of my reply, sorry if it's a pain (you might need to click it to expand it)...
Capture.JPG


EDIT: Heck it posted despite the error. Just ignore this post. Jimmmm…
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

Alexdc12
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Location: Essex

Re: Mixed gas

Post by Alexdc12 » Sun Jul 15, 2018 12:27 pm

PeeBee wrote:
Fri Jul 13, 2018 6:18 pm
Ah yes, sorry, CO2 cylinders have a different and male thread to avoid accidents. I doubt you'll easily find an adapter, the threads are quite kooky. You could get 60/40 (it is a compressed gas so could be at 3000PSI - CO2 is a liquid at about 8-900PSI) just remember you will need a higher pressure to get the carbonation you want.

For example. If you want the carbonation of, say, 10PSI you'd need 10 + 10/60*40 or 16.6PSI of 60/40 mixed gas for the same carbonation. Your tap might splutter a bit. To get decent (or should that be indecent?) amount of nitrogen to start dissolving you need 30+PSI (and a bomb shelter?).
Got some 60/40 gas today. Emptied the gas from the current keg by turning it upside down and releasing the gas. I've put it in at 16 psi and will see what happens.
Just re-read your reply again and are you saying I should be higher psi to get rid of any nitrogen in the beer or was that to get rid of nitrogen if I hadn't relieved the pressure from the keg?

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LeeH
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Mixed gas

Post by LeeH » Sun Jul 15, 2018 1:21 pm


You need 100% CO2 for anything apart from long cellar runs and cream flow beers such as John smiths smooth etc.

Post 2 quite helpfully told you not to buy 60/40.



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Alexdc12
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Re: Mixed gas

Post by Alexdc12 » Sun Jul 15, 2018 6:53 pm

LeeH wrote:
Sun Jul 15, 2018 1:21 pm
You need 100% CO2 for anything apart from long cellar runs and cream flow beers such as John smiths smooth etc.

Post 2 quite helpfully told you not to buy 60/40.



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I hear you. Post 6 also said I could. The 60/40 has bought it back to life, I couldn't warrant the expenditure on a new regulator etc at the moment so am just glad the 60/40 done the trick.
I will keep my eye out for a CO2 reg as everything you and peebee said makes perfect sense it just boils down to money.
Thanks

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LeeH
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Mixed gas

Post by LeeH » Sun Jul 15, 2018 8:04 pm

£15.98 for a reg.

https://rover.ebay.com/rover/0/0/0?mpre ... 2378369899

The main issue is you have effectively a bottle of CO2 That is 40% full. I pay 15 quid for a bottle so the payback is quick especially if you have bought 2 already.

HTH

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Alexdc12
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Location: Essex

Re: Mixed gas

Post by Alexdc12 » Sun Jul 15, 2018 8:18 pm

LeeH wrote:
Sun Jul 15, 2018 8:04 pm
£15.98 for a reg.

https://rover.ebay.com/rover/0/0/0?mpre ... 2378369899

The main issue is you have effectively a bottle of CO2 That is 40% full. I pay 15 quid for a bottle so the payback is quick especially if you have bought 2 already.

HTH

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I also have a wife! 😂

I will look into getting one. Thanks for the link.

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Re: Mixed gas

Post by PeeBee » Mon Jul 16, 2018 8:38 am

LeeH wrote:
Sun Jul 15, 2018 1:21 pm
You need 100% CO2 for anything apart from long cellar runs and cream flow beers such as John smiths smooth etc.

Post 2 quite helpfully told you not to buy 60/40.
Hi Lee. Choosing 60/40 over pure CO2 was simply to avoid a new regulator or dodgy bodging in the old mixed gas one. Putting the 60/40 gas in at 16.6PSI will be the same as putting pure CO2 in at 10PSI (I used 10PSI as an example, if that doesn't produce enough carbonation use proportionally more but as the pressure increases and the temperature of the beer in the keg is dipped well below 10C nitrogen starts having an impact).
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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Re: Mixed gas

Post by PeeBee » Mon Jul 16, 2018 9:03 am

Alexdc12 wrote:
Sun Jul 15, 2018 12:27 pm
...
Just re-read your reply again and are you saying I should be higher psi to get rid of any nitrogen in the beer or was that to get rid of nitrogen if I hadn't relieved the pressure from the keg?
It's all about "partial pressure", which isn't as complicated as most physics!

You'd been using 30/70 gas so over half of the gas in the keg would have been nitrogen. Had you connected a pure CO2 cylinder to the keg at, say, 10PSI then about half the gas in the keg would be nitrogen. The 50% of CO2 in the keg would start force carbonating the beer as if pure CO2 was used at just 5PSI (10PSI x 50%). Getting it?

When getting mixed gas the first number is always the CO2 (so 60/40 is 60% CO2).

The calculations are slightly complicated by our gauges actually reading PSIG, i.e. ignoring the weight of the atmosphere (14.7PSI-ish) - but at keg pressures you can get away with turning a blind eye to that.
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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