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Carb PSI vs Serving PSI

Discussion in 'Bottling/Kegging' started by brett1341, Feb 6, 2014.

 

  1. #1
    brett1341

    Well-Known Member

    Posted Feb 6, 2014
    Basic question, should they be different? I'm having issued withy the keg of dopplebock that I kegged two weeks ago. I had the fridge set a 45 degrees and the PSI at 15. This should have given me about 2.5 volumes. I did the 'set and forget' method, no shaking.

    When I try to pull a glass now, all I get is foam. I have 10 feet beer lines so I don't think line length is the problem and I am using a picnic tap, so I can adjust the height of the tap. Nothing seems to correct the foam.

    I asked the guy at the LHBS and he said the carb PSI should be the same as the serving PSI.

    Part of me thinks that I should bleed the excess CO2 in the tank and the serving PSI should be lower, like 3-4. But then it seems that if the serving PSI is lower, the beer will eventually equalize with the new headspace PSI and will go flat.

    Some direction would be greatly appreciated.
     
  2. #2
    JustLooking

    Well-Known Member

    Posted Feb 6, 2014
    This.


    Pressure and temperature control volumes of CO2. Line length controls foaming.
     
  3. #3
    PGEduardo

    Well-Known Member

    Posted Feb 6, 2014
    Where is your temp probe? Taped to the keg or dangling in the chamber? Make sure you control temp to the keg, not chamber ambient...
     
  4. #4
    BigFloyd

    Well-Known Member

    Posted Feb 6, 2014
    Drop your temp to 38-39*F and your pressure to 12psi. Let it sit a few hours. Release excess pressure for a second or so then give it a try.

    Also, use the tap like an on-off switch. Full open or closed. No in between. A partially opened tap or faucet is a sure-fire way to get foam.
     
    Beergnomes likes this.
  5. #5
    DrunkleJon

    Objects in mirror are closer than they appear  

    Posted Feb 6, 2014
    Agreed. Match the serving pressure to the carbonation pressure. Otherwise carbonation levels will balance out over time.

    Other things than line length that can cause foamy pours is the only half opening the tap as well as tap temperature/temperature stratification in the kegerator. Is it only the first pour that is foamy? Also, are there gas bubbles in the beer out lines?
     
  6. #6
    AnOldUR

    fer-men-TAY-shuhn  

    Posted Feb 6, 2014
    If I had to guess, I'd go with the pressure gauge being off.
     
  7. #7
    Scubadude918

    Well-Known Member

    Posted Feb 6, 2014
    1: Is it pouring excessively fast? (Could be too large beer line diameter)
    2: Is the full length of beer line the same temp as the keg? (If the line is warmer, it Causes foam 100% of the time)
    3: is the beer line/faucet clean (recommended line flush every 3 brews)
    4: if none the above apply, lower temp and pressure to achieve same carb as stated in above post.

    Hope this helps! :mug:


    ____________________________
    Primary: empty
    Secondary: Sierra Nevada Pale Ale Clone
    Secondary: Cider
     
  8. #8
    brett1341

    Well-Known Member

    Posted Feb 6, 2014
    Thanks for the replies.

    There are no air bubbles in the line.

    It is 3/16 beer line.

    The line is contained entirely within the fridge so it is the same temperature.

    All of the pours are foamy.

    The regulator may be off, how would I check that?

    Not sure if it helps at all, but I can disconnect my gas line and there is still enough pressure to pour as many glasses as I want and they are still foamy.

    I keep the excess line wrapped around the keg so their are no crinks or pinches.
     
  9. #9
    Scubadude918

    Well-Known Member

    Posted Feb 6, 2014
    Only way I could think to test the pressure would either be rig a pressure tester (tire pressure gauge or something like that) to your gas line or buy a new Gauge for the reg.


    ____________________________
    Primary: empty
    Secondary: Sierra Nevada Pale Ale Clone
    Secondary: Cider
     
  10. #10
    E_Marquez

    Well-Known Member

    Posted Feb 6, 2014
    drop the temp to 36~38 deg
    Lower the pressure to 10, bleed keg pressure let it come back up to the "new" lower set pressure and temp.. Let keg sit over night.. Bleed pressure again in morning, let sit for the day.. Draw a pint that second night... Let us know the results.

    If i tired serving at 15psi and 45 deg.. id get nothing but foam as well ( I know that as when I first started kegging... that is what I did, and foam is what I got)

    Dropping pressure and lowering temp as above fixed it for me.
     
    BigFloyd likes this.
  11. #11
    brett1341

    Well-Known Member

    Posted Feb 6, 2014
    I'll try your suggestion E_Marquez, thanks.
     
  12. #12
    JuanMoore

    Supporting Member  

    Posted Feb 6, 2014
    This. The warmer or more highly carbed the beer is, the slower/gentler the pour needs to be to prevent the CO2 from coming out of solution. Just a few degrees makes a huge difference. At 45° and 2.5 vol you'd need 30'+ of line to slow the pour to a trickle. Keep in mind that the beer warms a couple degrees as it's poured into the room temp glass, so if you want to drink 42° beer, you should store it at 40°.
     
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