Dispensing line length to prevent foaming?

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brewbrew
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Dispensing line length to prevent foaming?

Post by brewbrew » Tue Nov 12, 2024 12:58 pm

I have historically had good results with my all grain IPAs dispensed from a corny with CO2 at 12psi and 8 deg C - via 2m of 3/16" Valpar and a party tap. No foaming issues (apart from my very firsts attempt - I found out the hard way when my first corny was dispensed via 20cm of 3/8" and a bar tap and it performed like a foam generator).

I have for one reason and another had to stop my all grain operation and I have done a couple of Mangrove Jacks kits (good tasting beer and none of that "kit/extract" flavour that I remember from years ago with tinned kits). The problem I have encountered is that the beer comes out as 50% foam - impossible to dispense to a glass..... to draw a pint I need a 3 litre jug and 10 minutes of patience - even at 12psi, 8 deg C and 2m of 3/16" tube (all new so clean).

I notice that Mangrove Jacks instructions are all based on bottle dispensing - is it possible that they have added some sort of head retention agent such as alginate that screws up a keg dispense? Has anyone successfully done a Mangrove Jacks kit in a Corny without creating Xmas snow scenes?

I wonder if if could be that the stainless dip tube needs an internal scrub - any experience of this working?

Or should I extend my 3/16" tubing to say 3 or even 4m?

Thanks for any offered wisdom - I have a Pils kit that has just started to ferment and I don't want foam from this one.

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IPA
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Re: Dispensing line length to prevent foaming?

Post by IPA » Tue Nov 12, 2024 5:08 pm

There is only one reason that your beer is foaming and that is because it is over carbonated.
"You're not drunk if you can lie on the floor without holding on." Dean Martin

1. Life is not a journey to the grave with the intention of arriving safely in a pretty and well-preserved body, but rather to skid in sideways, thoroughly used, totally worn out and loudly proclaiming... "f*ck, what a trip

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paulg
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Re: Dispensing line length to prevent foaming?

Post by paulg » Wed Nov 13, 2024 5:31 pm

IPA wrote:
Tue Nov 12, 2024 5:08 pm
There is only one reason that your beer is foaming and that is because it is over carbonated.
Ian you have preached this for a long time and I agree with you.
I had the same troubles and eventually put a spunding valve on my keg and left it set at 12 psi.When I came to serve the beer I connected it up and applied the gas @ 12 psi.
Surprise surprise my previous foaming troubles were no more.
It would appear I was not fully fermenting the beer out before kegging and it was getting over carbinated

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Re: Dispensing line length to prevent foaming?

Post by IPA » Wed Nov 13, 2024 6:36 pm

paulg wrote:
Wed Nov 13, 2024 5:31 pm
IPA wrote:
Tue Nov 12, 2024 5:08 pm
There is only one reason that your beer is foaming and that is because it is over carbonated.
Ian you have preached this for a long time and I agree with you.
I had the same troubles and eventually put a spunding valve on my keg and left it set at 12 psi.When I came to serve the beer I connected it up and applied the gas @ 12 psi.
Surprise surprise my previous foaming troubles were no more.
It would appear I was not fully fermenting the beer out before kegging and it was getting over carbinated
Thanks Paul
Ian
"You're not drunk if you can lie on the floor without holding on." Dean Martin

1. Life is not a journey to the grave with the intention of arriving safely in a pretty and well-preserved body, but rather to skid in sideways, thoroughly used, totally worn out and loudly proclaiming... "f*ck, what a trip

It's better to lose time with friends than to lose friends with time (Portuguese proverb)

Be who you are
Because those that mind don't matter
And those that matter don't mind

paulg
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Posts: 67
Joined: Sat Feb 16, 2019 3:56 pm
Location: Corfu,Greece formely Essex/Suffolk border UK

Re: Dispensing line length to prevent foaming?

Post by paulg » Thu Nov 14, 2024 2:52 pm

IPA wrote:
Wed Nov 13, 2024 6:36 pm
paulg wrote:
Wed Nov 13, 2024 5:31 pm
IPA wrote:
Tue Nov 12, 2024 5:08 pm
There is only one reason that your beer is foaming and that is because it is over carbonated.
Ian you have preached this for a long time and I agree with you.
I had the same troubles and eventually put a spunding valve on my keg and left it set at 12 psi.When I came to serve the beer I connected it up and applied the gas @ 12 psi.
Surprise surprise my previous foaming troubles were no more.
It would appear I was not fully fermenting the beer out before kegging and it was getting over carbinated
Thanks Paul
Ian
I also followed your other advice and converted my sankey kegs to floating pickups using triclamp corney post type fittings and caskwidge floats

brewbrew
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Re: Dispensing line length to prevent foaming? - NOT over carbonation

Post by brewbrew » Mon Dec 09, 2024 11:39 am

UPDATE:
I thought members would be interested to know that I have solved this problem.

Despite the firm advice from IPA stating that it "is because it is over carbonated", that was not the cause. It was not about the line length either. The foaming beer in question was quite low in "fizz": 12psi at 8 deg C is 2.2 volumes which is quite low for an IPA according to my taste and most brew experts.

I have made the same brew again and following advice from an experienced pub landlord, I invested in a dip tube brush - the use of which shifted quite a bit of long term muck out of the tube. This new brew has zero foaming when dispensed at the same 12psi and 8 deg C (using the same (good quality) thermo controls and gas regulator (same gas bottle and Valpar hose in and out). I have even managed to increase the gas presure to 17psi at 8 dec C to achieve 2.6 vols of CO2 (ideal to my taste) with zero foaming even on a quick pour and a modest sparkle in the beverage.

It was dirt, not over carbonation that was the problem. I believe the science behind it is all about bubble nucleation on the rough surface of the dirty tube - a polished surface has stopped it.

nallum
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Re: Dispensing line length to prevent foaming?

Post by nallum » Mon Dec 09, 2024 9:18 pm

To be fair, that's a different problem. I'm sure IPA didn't assume you were too economical on the sanitary side of things, even though you are by your own admission.

BTW, the 'landlord' is no different from those occupying any other human endeavour, being populated by the 'good', 'bad' and 'ugly'. Most are bad to ugly, in reality. Wankers, for short.

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