Nitrogen setup - all head, and flat as a pancake?

[user 40839]

A friend of mine (honestly, it's a friend, not me! I have to wait another couple of months for my nitrogen setup!) is having some serious difficulty with his new tap, and it's driving us both crazy, we can't figure out what's going on.

Keg is carbed to normal volume with CO2.
Beer line is about 15 feet (Tygon)
Beer gas pressure is 30psi.
Stout faucet is new, restrictor plate is clean and all five holes are unblocked.

But... the beer is coming out pure head, and flat as a pancake.

Tried purging the keg, recarbed with CO2, then put it back on the nitro. No joy. Messed with every pressure under the sun with the regulator, nada.

The only thing I can think of at this point is that it's not actually beer gas in the tank, it's pure Nitrogen, which would explain the beer losing it's carbonation. But any other thoughts?

 

[IrregularPulse]

stout faucet with restrictor plate?

 

[user 40839]

Yup, sorry, should have pointed that out. Stout faucet with restrictor plate indeed.

 

[dogtailale]

I kind of had the same problem although was CO2 all foam and flat.

For the heck of it try these two threads. It wont hurt.

https://www.homebrewtalk.com/f35/disco-sucks-192166/

https://www.homebrewtalk.com/f35/disco-192168/

Hope they might help.

 

[dogtailale]

Opps I missed the part on the 100% nito

I believe it should be mixed AKA beer gas

 

[Naked_Eskimo]

Serving at 30PSI?

 

[IrregularPulse]

Serving at 30PSI?

This is common for beer gas (co2/nitro blend)

 

[GilaMinumBeer]

Are you certain you are carbonating to YOUR desired vol of CO2?

What you are doing should work, since the Nit is less soluable it should serve to keep the pressure in the keg and keep the CO2 dissolved. I am wondering if this is a balancing issue. Is the pour crazy fast?

 

[DKershner]

How long was the beer carbing on pure CO2? Did it pour fine with just the CO2 pushing it?

How quickly does the glass fill out of the tap? What is the kegerator setup? Keezer with a collar or through a tower?

 

[user 40839]

I'm not saying the gas is pure Nitrogen - it's what I'm suspecting at this stage, given we've (I think) tried everything else.

Gila, I had the beer when it was on CO2, and it was spot on. The guy who has this in his setup knows what he's doing (moreso than me, that's for sure) and follows the usual chart in carbing to style. His temp is set to about 36 degrees, on a keezer with an 8-tap tower, which is cooled via glycol (or might be just recirculating water, can't remember). He had two beers on this stout setup - one was a stout that was right around 2 volumes of CO2 @ 6PSI that went on the nitro first.

First pour, the beer came out all head, which took 4-5 minutes to settle out to where it was anywhere drinkable. After being on gas for a few days, it came out flat as pancake. Suspecting that the beer was undercarbed, he switched over a keg of schwarzbier which was carbed at about 2.5 volumes of CO2 @ 10PSI, and it had the exact same result - all head, and after it settled out, no carbonation.

After messing with it myself, the pour certainly seems to be coming out faster than I expect, but while that would explain the crazy amounts of head (insert joke here), would it also cause the beer to lose almost all carbonation? (Unless the cascading head is stripping the CO2 of what little carbonation is left, after it passed through the restrictor plate?)

 

[DKershner]

After messing with it myself, the pour certainly seems to be coming out faster than I expect, but while that would explain the crazy amounts of head (insert joke here), would it also cause the beer to lose almost all carbonation? (Unless the cascading head is stripping the CO2 of what little carbonation is left, after it passed through the restrictor plate?)

Similar to overcarbing beer to more than your lines can handle, the end result is an undercarbed beer. The restrictor plate and resulting head do strip carbonation from the beer, you are just stripping a lot of it. You are just doing so with beergas or nitrogen (wouldn't matter) which is NOT overcarbing the beer, but still overdoing it for your system. 15ft would seem like enough, but I guess not.

At least, that is what it seems like since all other variables seem accounted for.

 

[GilaMinumBeer]

After messing with it myself, the pour certainly seems to be coming out faster than I expect, but while that would explain the crazy amounts of head (insert joke here), would it also cause the beer to lose almost all carbonation? (Unless the cascading head is stripping the CO2 of what little carbonation is left, after it passed through the restrictor plate?)

This. Entirely possible. If the system is out of balance the vigour of the pour and the time waited for the head to settle can result in a flat beer. With the nitro, the beer should cascade and take only a minute (less really) max to settle into a good 1 or 2 finger head prime for drinkin'.

I "think" the system is out of balance.

Been a while since I have had to balance my system but, IIRC, on my seltzer line I have 20 to 30 foot (coiled around the keg) to carb the water at 30psi and have it pour properly.

 

[DKershner]

Been a while since I have had to balance my system but, IIRC, on my seltzer line I have 20 to 30 foot (coiled around the keg) to carb the water at 30psi and have it pour properly.

Beer line resistances range a bit, but hover around 2.2psi/ft. (for 3/16")

His 15ft SHOULD give him 33psi of resistance...but life isn't always so easy, which is why most people on this board use 10ft (22psi) of resistance to serve beers in the 10-12psi range. It just comes out slower.

 

[klyph]

Wouldn't you need longer lines to balance the higher serving pressure?

<-- zero experience.

edit: Oops, slow reader...

 

[GilaMinumBeer]

Beer line resistances range a bit, but hover around 2.2psi/ft. (for 3/16")

His 15ft SHOULD give him 33psi of resistance...but life isn't always so easy, which is why most people on this board use 10ft (22psi) of resistance to serve beers in the 10-12psi range. It just comes out slower.

Yes. But what of the interplay of the restrictor plate and back pressure. This is what I have trouble finding a good source on how to balance against. Like the analogy of a water hose, the static pressure is ~60psi but open the faucet and that pressure drops dramatically. Add resitance by way of a spray wand and you build back closer to static and the vigour of the water stream becomes dramatic to violent.

Typical balancing guides do not offer info on the resistance created by the restrictor plate which generates a back pressure imbalance that is not accounted for. You want the plate to break the gas out of solution but you don;t want the solution launching at you like a spit pea soup.

Right?

 

[DKershner]

Typical balancing guides do not offer info on the resistance created by the restrictor plate which generates a back pressure imbalance that is not accounted for. You want the plate to break the gas out of solution but you don;t want the solution launching at you like a spit pea soup.

I have seen sources that say restrictor plates offer enough restriction on their own that no lengthening of line is needed at all.

I am currently pouring through my stout tap as an experiment at 12psi (pure CO2) and it is coming out with the correct amount of head and at the same speed as my unrestricted taps, but the head is quite creamy by comparison. I have 10ft of beer line. At 33psi, I would venture to say the glass would all be foam.

My conclusion: Not all stout taps are created equally.

My analogy to your example would be a tiny thumb being placed over the hose vs a bigger thumb, of course the vigor of the water would be different.

 

[GilaMinumBeer]

I have seen sources that say restrictor plates offer enough restriction on their own that no lengthening of line is needed at all.

I am currently pouring through my stout tap as an experiment at 12psi (pure CO2) and it is coming out with the correct amount of head and at the same speed as my unrestricted taps, but the head is quite creamy by comparison. I have 10ft of beer line. At 33psi, I would venture to say the glass would all be foam.

My conclusion: Not all stout taps are created equally.

Yes! I have this too. The pour from straight CO2 at normal pressure is fine enough that I see no need for the Nitro outside from just wanting to "play".

 

[DKershner]

Yes! I have this too. The pour from straight CO2 at normal pressure is fine enough that I see no need for the Nitro outside from just wanting to "play".

Makes you wonder what these people have who are pouring guiness with 5ft of line at 34psi...do we just have crappy faucets or something?

Mine looks like this one: http://www.beveragefactory.com/draftbeer/faucets/faucets/JESF-3.shtml

 

[GilaMinumBeer]

Makes you wonder what these people have who are pouring guiness with 5ft of line at 34psi...do we just have crappy faucets or something?

Mine looks like this one: http://www.beveragefactory.com/draftbeer/faucets/faucets/JESF-3.shtml

Exactly. Mine is a full stainless version very similar to the MicroM Stout/Ale faucet except mine also has a stainless nozzle. One of those two stage operations (forward pour, back for foam).

So, cause I actually had to go with a shorter line than the balancing suggests to get the foam right too on straight CO2 at 12 to 16psi. And I still think it's too slow a pour.

It boggles the mind.

 

[DKershner]

I really find it hard to believe there is that much variance in stout taps...

Mine pours at a completely normal rate at 12psi, maybe a second or two extra for a pour.

I have a tank of pure nitro that I use for wine...a stout is going to be coming on tap soon so I will have to figure out how to work this, but it seems to me that carbing the stout at about 8psi and then pushing it with about 12psi of co2+nitro would work great...

That is of course about 1/3 the pressure I should be pouring at according to conventional stout serving wisdom.

This is all very confusing.

 

[GilaMinumBeer]

As many thread as I have read about this same issue, I really think there is a plate back pressure phenomenon that isn't accounted for by the numbers. And, I bet the industry figures an extra 10 foot more length on these systems for trial and error wiggle room.

Just a guess.

 

[DKershner]

As many thread as I have read about this same issue, I really think there is a plate back pressure phenomenon that isn't accounted for by the numbers. And, I bet the industry figures an extra 10 foot more length on these systems for trial and error wiggle room.

Just a guess.

By phenomenon do you just mean inconsistency in the actual plates? As in, one hose nozzle sprays differently than another due to the size of the nozzle?

I just find it hard to believe that some faucets would take 6min to pour a pint at 10psi and others take 10seconds with the same line length. But that really does seem to be the case...

 

[GilaMinumBeer]

By phenomenon do you just mean inconsistency in the actual plates? As in, one hose nozzle sprays differently than another due to the size of the nozzle?

I just find it hard to believe that some faucets would take 6min to pour a pint at 10psi and others take 10seconds with the same line length. But that really does seem to be the case...

Yeah something like that. Maybe the "pore" size in the plates varies. I dunno. Just seems odd that there is so much floating around saying 30psi with 15 foot of line at temp x and yet so many are reporting pressure washer type pours and nothing but foam. Just screams unbalanced pressure to me and that pressure would have to be back pressure created by the restriction from the plate and not balanced out by the line itself.

Like I said, but I wonder.

 

[user 40839]

Interesting. So could be something as completely random as the holes in the restrictor plate. Well, I'm heading up there tomorrow to work on a Dark Lord clone we have in the works, and will futz with line length.

 

[DKershner]

Interesting. So could be something as completely random as the holes in the restrictor plate. Well, I'm heading up there tomorrow to work on a Dark Lord clone we have in the works, and will futz with line length.

Let us know how it goes...we will probably need to do it ourselves later.