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  • long draw draft problem

    getting some odd foam issues with our hoppy wheat ale.

    serving tank is at 35-37 f, and head preasure 11psi, which is standard for us.
    glycol in the trunk line is at 31
    the walk in at the front bar- with about 12' of exposed beer line inside- gets alot of opening/closing doors- big range from 32 coldest-38 hottest

    at open, beer pours fine. but at night when it gets busy we get little explosions of foam. will pour ok, then explode with foam, then ok, then foam, etc.

    couldnt see any issues at the tank, trunk line seems cold, cleaned out flojet beer pump, no change in problem.

    check the tap for a clog/obstruction? some sort of odd co2 leak or loose fitting somewhere?

    im a bit stumped....

  • #2
    You need to ensure that you maintain pressure at or above CO2 equillibrium pressure at all points along the line. When you open the faucet, the pressure just before it will drop a little because the beer has to push through the line to get there. Keg systems will have the pressure set higher to push the beer through the line resistance and if it changes in height from cellar to faucet height, compensate for head pressure due to the column of beer. If you are going from a basement cooler, beer gas is often used to dispense the beer so you can maintain the equilibrium co2 pressure at the faucet and overcome line resistance.

    One solution is to raise the co2 top pressure in the bbt a few psi to push the beer, but it will gradually increase the carbonation level of the beer over days/ weeks. You could shut off co2 overnight and release excess pressure to limit this but it is a hassle.
    Or you could use a co2/ n2 blend on top of the tank. If the beer sits in the tank for a while, say 2 weeks or more, you will get nitrogen dissolving in the beer affecting the taste/ feel.
    Probably the better solution is to get an air powered diaphragm pump connected to the brite to push the beer to the tap. This way you set the tank top co2 pressure to maintain the carbonation level and use the pump to provide dispense pressure.

    The BA have a draught quality booklet which would be helpful.

    Comment


    • #3
      As noted above, we run beer via flojet beer pumps.

      Comment


      • #4
        Originally posted by brain medicine View Post
        As noted above, we run beer via flojet beer pumps.
        You buried the lead and i did not see it.

        What is pressure on your flowjet? Turn it up?

        Look at tank temperature, cooler temperature, insulation on draught lines

        Good luck

        Comment


        • #5
          yeah, you're doing it again. i listed all that stuff above.

          pressure on the flojet just makes it pump faster, doesnt have anything to do with carbonation. (unless i completely misunderstand the principle of the beer pump)



          three on draft right now. all in same walk in cooler in brewery. all running in the same trunk line. all being poured out of the same walk in behind the main bar. two pour fine. only the hoppy wheat session is giving us foam.

          thats what i cant figure out. why one would be blasting foam while the others pour fine.

          - either the serving tank pressure is too high/low (bad gauge reading, blocked port, co2 valve throttled down for some reason)
          - its a temperature problem- (cant see that being the issue due to circumstances noted directly above)
          - or its something with the beer itself- (they did a crappy racking job and pulled a ton of hop debris? as volume gets lower it starts to cause more problems?)

          or something mechanical like a blocked valve? something in the draft line? tap needs to be disassembled?

          Comment


          • #6
            Can you easily switch lines around? Try putting the problematic beer on a different line. Leave everything else the same. If the problem persists with that beer, you know its a beer problem. If the problem solves for that beer but happens again, you know its a line problem. You can then start cleaning, fixing, or replacing parts on that line until you find the problem or it gets fixed. Its obviously not a system wide issue since two other lines are running just fine. This assumes that you have made sure that the tank pressures are correct and getting good flow rates.

            Comment


            • #7
              didnt know it but the team already swapped the lines, no change in results unfortunately.

              as im up in bay area and they're down in baja we're going back and forth bouncing ideas.

              according to photo sent to me right now, tank is about 20% full. i figured that could be a problem with bad racking and lots of hop sludge/yeast getting into the brite, since the volume is low in tank. but they say it was a problem before the volume got low.

              i did however see a co2 supply line ball valve that definitely did not look fully open. so we'll get that open and inspect any other valves or lines.

              i could see that being a factor, but for some reason to me it still seems like there's gotta be something else happening....
              Last edited by brain medicine; 06-25-2018, 03:18 PM.

              Comment


              • #8
                I like the suggestion above: Isolate the problem.

                One thing you did not list: Carb level. @35F, 11psi is good for ~2.6 v/v. @37, it's good for ~2.5 v/v.

                You say "exposed lines" for 12' in the cooler. Do you mean uninsulated? Insulate them. Not only will this keep your lines temps more stable, it will eliminate dripping condensate in the cooler and the problems that follow.

                Is/are your tower/faucets glycol cooled? This usually causes foaming on opening, not at the end of the day, so I'll assume yes.

                Aside from those, do you have choker lines installed? If so, check the barb fittings that are between the trunk lines and the choker lines. If there is any restriction here, it creates a venturi effect with a low-pressure zone downstream of the restriction. The beer will "break" in this zone, causing blobs of foam to come down the lines after a few pours. It won't show up unless you're moving a bit of beer, as the pressure stabilizes when the faucets are closed. I had this problem and it drove me nuts before I finally figured it out. Symptoms were very similar to yours.
                Timm Turrentine

                Brewerywright,
                Terminal Gravity Brewing,
                Enterprise. Oregon.

                Comment


                • #9
                  they dont have a carb meter yet down there, so just use temp/pressure and theoretical carb level. pressure at the SV and then the brewery cooler avg temp.

                  12' exposed lines in cooler is indeed uninsulated 3/16 choker line extending beyond the glycol trunk. length per draft system recommendation. will see about insulating.

                  taps are in a shadow box in the wall of the cooler.

                  i hesitate to focus on temp at these areas as the cause since the other beers are pouring fine.

                  will have the crew inspect the lines and connections between trunk and choker lines. but again, doesnt seem likely as the problem was reported to be the same even when the lines/tap were switched. and the other beers are pouring fine. and this has been our first real foam problem in a year of service. worth a look, but seems unlikely.

                  but when you say restriction at the barb union, what are you referring to? a clog? a bulge in the tubing? we bought 5/16 to 3/16 adapter barbs and havent had any problems with foamy beer prior to this. i dont recall seeing any options for a "full bore" barb union. just standard fitting sizes. is there some other type adapter with larger diameter? should we have gone 3/8 to 1/4?

                  Comment


                  • #10
                    Brain:

                    I had this problem when I bought hose couplers at the local hdwre store. I was two couplers short in my order from my draught system supplier. It took me forever to narrow the problem down to the two couplers, since I had insulated all the lines. Once I stripped the insulation off the part of the trunk where I went from 3/8 to 3/16, I could see the slugs of foam forming immediately after the two barb fittings. Looking closer, the hdwre store couplers are rated by their OD, so the ID is restricted compared to the line. The beer couplers are rated by their ID, so you need to heat the tubing some to get it over them, but there is no restriction due to the coupler.

                    Where the too-small ID coupler meets the standard ID tubing downstream of the coupler, there is a sudden increase in ID. This results in a local drop in pressure (venturi effect), and beer breaking out.

                    But if the foaming problem travels with the keg, it isn't the lines, obviously. Sounds like accidental over-carbing.
                    Timm Turrentine

                    Brewerywright,
                    Terminal Gravity Brewing,
                    Enterprise. Oregon.

                    Comment


                    • #11
                      I'll add my anecdote to this as I haven't seen anything like it related in any of my searches for this same problem. I have a similar arrangement of serving tanks (jacketed) and glycol chilled trunk line going uninsulated through the walk in, then back into a glycol chilled line along with the kegged beer lines to the tap. No kegged beer was breaking out at the tap, but the beer from the serving tanks would only pour fine for a pint or two and then be nothing but foam. Ultimately I got a gas mixer and set my head pressure to fourteen, as the number of points that the line could change temperature (and diameter, as the serving tank lines also have a quick disconnect feature that increases the id in the walk in) proved too many variables for me to control given that I wanted to successfully and immediately serve beer. This solved my problem in the short term. I also lowered the temperature of the walk in as much as was reasonable, since it was already around thirty two degrees. However, what I ultimately came to realize was that I had carbonated the beer past the ability of my draft system to handle it, as the beers in question were in the 2.7 volume range. They were pouring fine if the line was still and cold, but then the line would get to where the gas had broken out (the beer that had waited in the walk in) and need to be exhausted of that gas pocket before it could pour another decent pint. Do I ultimately regret the quick disconnect feature in the walk in and wish that I had serving tank lines that were glycol chilled for their entire run? Certainly. But I was able to overcome the problem for about eight hundred bucks and move on with the rest of my business. Hopefully my mistake is helpful to someone somewhere.

                      Comment


                      • #12
                        Wheat Beers

                        I've found with our hefeweizens that towards the end of the keg there will be excess foam on top, which would make its way through the line even before the keg was finished. This was when we were trying to serve the beers at a traditional high carbonation level (around 3.5 volumes which was a rookie mistake). My assumption is that CO2 breaks out of the beer as the keg gets emptied creating the foam, and like others have said if you don't have a high enough pressure on top of the beer this will get worse. Ultimately we solved this by carbonating to a little bit lower level, around the 3.0 level and haven't had the issue again. It sounds like you aren't carbonating that high, but if you don't have a high enough pressure on the tank the CO2 will break out during serving which will likely be worse with something that has a lot of wheat.

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