Troubleshooting a Nitro Tap setup

[CrystalShip]

Hey all! I have had a nitro setup for about seven months now and I still can't figure this thing out. After searching through the forums I have found so much contradicting information that I am even more confused than when I started.

Basically I am getting incredibly foamy pours that take forever to settle out and do not cascade the way they are supposed to. When pouring, I get a pint of about 80-90% foam that eventually settles out to about 60% beer.

I have had the same keg of homebrewed choc-pb stout on it since the beginning. Here are some specifics:

-using 70/30 beer gas blend
-kegerator is 40 degrees F
-beer line is 5ft long (even though most people say this shouldn't matter)
-beer was originally over carbed but I disconnected it and bled of gas every day until it was pretty much flat, then reconnected it to beer gas. It would pour ok for a day or two, then become foamy again.

I had this thing hooked up with 30psi, then tried 25, 20, 15, and now I'm using 10psi... all with foamy pours.

so I was thinking...and let me know if my math or method is incorrect in this one... they say to carbonate to about 1.2-1.7 vol with co2 first, then push with beer gas. wouldn't just hooking up the blended gas carb the beer? and to get to 1.2-1.7 vol it wouldn't take very much?

ex. so at 40degrees and 1.5 vol of co2 (according to the force carb chart) I need about 2psi of co2 to reach those levels. my beer gas is 30% co2 so I would need to set the regulator to like 8psi? Why are people recommending 30psi?

Some one help! :smack::smack:

 

[ChemEng]

I have had this problem before... you are overcarbed. Due to the solubility of CO2 at 40 degF you can not de-carbonate the beer enough at atmospheric pressure to fix the problem. You need to disconnect the keg, take it out of the refrigerator and bleed off the pressure. Over the next 36 hours keep bleeding the pressure off every few hours as the beer warms up to room temperature.

After 36 hours, put the keg back in the fridge on 30 psig beergas.

Let it cool for 24 hours then tap it and give it a try. Should be much better.

 

[CrystalShip]

thanks for the reply, but I already did that. The keg sat out in my garage not hooked up to any gas for over a week and I bled off pressure everyday until no more came out. I then put it back into the kegerator and reconnected the beer gas and it poured ok for a couple days (except it was kinda flat) the went back to being foamy again

 

[Tiber_Brew]

If you have beer carbed to around 1.5 vol CO2 +/- 0.2, served at around 45-50 deg F with a 70/30 mix at 26-30 psi at the diffuser, you should get perfect pours. Do you have an uncooled or uninsulated tap tower? Do you have a quality reg? Was your beer gas filled from a reputable source? Have you taken the nozzle apart and inspected the diffuser plate? Maybe a few of the holes are clogged?

 

[CrystalShip]

the keezer stays at a constant 40degrees F and flows through shanks that are attached through the collar (no tower) I ordered the whole nitro kit (including regulator) through kegoutlet.com. The tank was purchased and fille through a fairly reputable source ( even though the first one they gave me was empty). I pulled the nozzle off last night and inspected/cleaned it so I don't think its that.

Like I said earlier-after I degassed the beer I had good pours for a couple days So I think the beer is becoming over carbonated somehow even though the regulator is only set to 10psi right now.

 

[CrystalShip]

is my method of thinking flawed here.... shouldn't 25-30 psi of 70/30 beer gas overcarbonate a beer?

30*.30= 9psi 9psi co2 @40degrees F = 2.2vol = overcarbed?

can someone explain this to me?

 

[Tiber_Brew]

Like I said earlier-after I degassed the beer I had good pours for a couple days So I think the beer is becoming over carbonated somehow even though the regulator is only set to 10psi right now.

Off the top of my head, there are only two things that could be responsible for that. 1. You got CO2 instead of beer gas (or your ratio isn't as stated), or 2. your regulator is failing. I think #1 sounds more likely. There could also be something else we're missing here.

 

[Tiber_Brew]

is my method of thinking flawed here.... shouldn't 25-30 psi of 70/30 beer gas overcarbonate a beer?

30*.30= 9psi 9psi co2 @40degrees F = 2.2vol = overcarbed?

can someone explain this to me?

I don't think that's how it works. My nitro setup is 70/30 and kept at 26 psi at 51 degrees F. My pours are flawless (you know, more or less)

 

[CrystalShip]

maybe they did label the tank wrong...I'll hook up a cobra tap to it after work to check out its carbonation.

thanks for the idea

 

[Tiber_Brew]

No problem. Hope that solves your issue.

 

[CrystalShip]

I tested out the beer by serving through the cobra tap and it is definitely over carbonated.

The bottle has a label that says 70% nitrogen, 30% co2 right on it...

You think there is any other way to actually test the gas in the bottle to make sure it is labeled wrong before I take it back to the place and complain?

 

[ajdelange]

is my method of thinking flawed here.... shouldn't 25-30 psi of 70/30 beer gas overcarbonate a beer?

30*.30= 9psi 9psi co2 @40degrees F = 2.2vol = overcarbed?

can someone explain this to me?

Partial pressures are absolute. Thus the partial pressure of CO2 in a 30% mix at 30 psig is
.3*(30+14.7) = 13.41 psia which is -1.29 psig.

Your math may have been wrong but 1 bar absolute (0 bar gauge) is just about the right partial of CO2 to give you the volume you want for a good pour at around 30 psig total pressure.

 

[Tiber_Brew]

I tested out the beer by serving through the cobra tap and it is definitely over carbonated.

The bottle has a label that says 70% nitrogen, 30% co2 right on it...

You think there is any other way to actually test the gas in the bottle to make sure it is labeled wrong before I take it back to the place and complain?

I'm convinced that your tank was filled with CO2, not beer gas. Either that or it's 30/70 instead of 70/30 (N2/CO2). Somebody somewhere along the line screwed up your tank fill and you should be entitled to a replacement.

 

[ajdelange]

You think there is any other way to actually test the gas in the bottle to make sure it is labeled wrong before I take it back to the place and complain?

Yes. Fill a glass (preferably something like a Kölsch Stange) with water (to which you have added a tsp or so of bicarbonate of soda or pickling lime) and invert it in a tray of the same water without spilling any. Now take a hose from your regulator, let enough gas flow to purge the line of any air and then bubble the gas into the glass until it is full with the gas to some convenient level. Remove the tube and put the tray in the fridge. The CO2 will dissolve in the water, the nitrogen will not and the water level in the glass will rise. The amount of rise will give you a rough idea as to how much of the gas is CO2. If it is 100% CO2 the water level will eventually reach the top of the glass (100% decrease in volume). If it is 30% CO2 the volume of air will decrease by 30%.

 

[CrystalShip]

Yes. Fill a glass (preferably something like a Kölsch Stange) with water (to which you have added a tsp or so of bicarbonate of soda or pickling lime) and invert it in a tray of the same water without spilling any. Now take a hose from your regulator, let enough gas flow to purge the line of any air and then bubble the gas into the glass until it is full with the gas to some convenient level. Remove the tube and put the tray in the fridge. The CO2 will dissolve in the water, the nitrogen will not and the water level in the glass will rise. The amount of rise will give you a rough idea as to how much of the gas is CO2. If it is 100% CO2 the water level will eventually reach the top of the glass (100% decrease in volume). If it is 30% CO2 the volume of air will decrease by 30%.

Holy crap...that's some bill Nye the science guy stuff!

 

[Tiber_Brew]

Yes. Fill a glass (preferably something like a Kölsch Stange) with water (to which you have added a tsp or so of bicarbonate of soda or pickling lime) and invert it in a tray of the same water without spilling any. Now take a hose from your regulator, let enough gas flow to purge the line of any air and then bubble the gas into the glass until it is full with the gas to some convenient level. Remove the tube and put the tray in the fridge. The CO2 will dissolve in the water, the nitrogen will not and the water level in the glass will rise. The amount of rise will give you a rough idea as to how much of the gas is CO2. If it is 100% CO2 the water level will eventually reach the top of the glass (100% decrease in volume). If it is 30% CO2 the volume of air will decrease by 30%.

Brilliant.

 

[BBBF]

Yes. Fill a glass (preferably something like a Kölsch Stange) with water (to which you have added a tsp or so of bicarbonate of soda or pickling lime) and invert it in a tray of the same water without spilling any. Now take a hose from your regulator, let enough gas flow to purge the line of any air and then bubble the gas into the glass until it is full with the gas to some convenient level. Remove the tube and put the tray in the fridge. The CO2 will dissolve in the water, the nitrogen will not and the water level in the glass will rise. The amount of rise will give you a rough idea as to how much of the gas is CO2. If it is 100% CO2 the water level will eventually reach the top of the glass (100% decrease in volume). If it is 30% CO2 the volume of air will decrease by 30%.

I like the way you are thinking, but I have a much simpler idea. Get a plastic soda bottle and a carbonator cap. Fill the bottle about 80% of the way with ice cold water, squeeze the bottle to get rid of the air and put on the carbonator cap. Then connect the bottle to your gas and inflate it, disconnect the gas and shake. If 100% of the gas dissolves, it's 100% CO2. If 30% dissolves, it's the right ratio. If 70% dissolves, they mixed up the ratios.

 

[dustinboyd]

OP, did you ever get your problem solved? I know this thread is old, but I am having the identical problem with an identical setup. I am starting to think my cylinder is pure co2 now.

Let me know if you figured it out, thanks!