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  • Overhead beer lines and fobbing

    We've been operating with overhead beer lines now for over seven months, and are now actively seeking a solution. What I have is a cooler behind the bar that feeds a python of about 40 feet. This trunk line runs overhead, close to the ceiling, and drops down into the bar through a column and then on to the taps. Each line has a separate regulator. The problem we have been having is that the beer pours nicely up to about a third of the pint glass (20 oz), and then starts to deliver a steady stream of foam. I'm suspecting that the gas is pooling up at the high point, and then just dumping into the glass. Anyone have any ideas for a solution? One suggestion was something called an inline flow restrictor, but I don't know much about this.

    Fortunately we don't sell a whole lot of the kegged stuff, since we are an all cask brewery, but this problem will get worse this summer as it gets busier.

  • #2
    Streaking

    BeerManWalking,

    Streaking or Flashing is caused when the applied pressure is too low to keep the beer properly pressurized in the beer line. This can occur in lines which are improperly (under restricted). This could also be a function of the tempurature of the beer in the line. Is this a forced air system or a water/glycol cooled system? It would seem that a 40 ft + run should be water/glycol cooled. Measure the tempuraure of the beer exiting the faucet. It should be near 34-36 F and shouldn't vary more than 3 degrees from your keg tempurature. Any higher than 37-38 F and you will have problems, depending on your CO2 Volumes.

    Because each beer is on its own regulator, you may wish to increase the pressure of one of the beers. Do this one pound at a time until you see a noticeable difference. Because the applied pressure is lower than the internal pressure in the keg, the CO2 migrates out of the beer. As you mentioned, the CO2 will migrate to the high point in the system. When the faucet is newly opened the beer flows clear but soon the foam reaches the faucet.

    Did you design and install this system? Send me the specs on the length of the Python run. Let me know what the rise and fall of the system are. Measure the rise from the bottom of the keg to the highest point in the system and then also measure the drop from the highest point down to the faucet.

    Let me know what kind of material your lines are. Polyethylene, Vinyl, or Barrier. Also let me know what kind of restriction you already have on your lines. At 40 ft, you probably have 3/8" lines with a 3/16" choker (restriction). Any idea how long the choker length is?

    You'll get this thing figured out sooner than later.

    Regards,
    Last edited by Todd; 04-01-2009, 12:23 AM.
    Todd Malloy
    Director of Brewing
    Glenwood Canyon Brewing Co.
    Glenwood Springs, Colorado

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    • #3
      Originally posted by Todd
      Measure the tempuraure of the beer exiting the faucet. It should be near 34-36 F and shouldn't vary more than 3 degrees from your keg tempurature. Any higher than 37-38 F and you will have problems, depending on your CO2 Volumes.
      Can't you work the balance for a draft system through pressure, restrictions and other adjustments to pour beer without excessive foaming for a much greater range of temps than that? 38F and below is WAY to cold for proper appreciation of the flavors and aromas in a beer.
      I have had beer served to me in the mid 40s that was poured properly, both in the US and especially in the UK. If a place serves their beer that cold, I don't patronize them. That is not how to enjoy a good beer, IMHO.
      -Lyle C. Brown
      Brewer
      Camelot Brewing Co.

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      • #4
        Temp - Pressure relationship

        Beerking1,

        Yes, you are correct. I have recently been working with the large domestic brewers who usually require the system temps to remain in the range I previously mentioned. I typically recommend these temps as a guide for tempurature/pressure balances within these systems. You most certainly can run a longer choker length to maintain pressure balance in a warmer system.

        I agree with you about drinking beer at 40 F +. I am parital to English style ales and have been schooled to brew, cellar and maintain these styles. I have even consumed cellar tempurature beers at 60 F and truly enjoy the flavors and aromas associated with these styles.

        In terms of troubleshooting this problem for BeerManWalking, I will also need to know his altitude, his beer tempuratures, the style of beer he is pouring, and whether he has bent tube assemblies, and the length of the shanks on the back side of his faucets. It would also be helpful to understand what flow rate he is trying to achieve coming from the faucet.


        Regards,
        Todd Malloy
        Director of Brewing
        Glenwood Canyon Brewing Co.
        Glenwood Springs, Colorado

        Comment


        • #5
          Our solution

          I'm with Todd, it's always best to run the calculations to ensure that you are balancing the system properly. In addition, it allows you to predict any changes, such as serving at a slightly warmer temperature.

          We dealt with a similar issue for some time after opening our bottling facitility. What we eventually did was to add in-line beer pumps to boost the line pressure rather than simply turning up the tank pressure.

          In addition, we decided to use the European restrictor-style taps when we installed the bar, that allows the bartender to provide a fine tuning on their end. It's usually not necessary, except when they are pouring pint after pint on busy nights. It can get a bit harried. There are also, of course, times when the CO2 volumes in the pre-packaging tank don't remain the same after being transfered to the 7bbl serving tanks.

          The pumps were an easy to install solution and use compressed air from the brewery.

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          • #6
            Measurements

            Sorry for taking so long - my 80 hour work week gets in the way.

            I wouldn't say that I "designed" the system, because that makes it sound like I know what I'm doing, but I did build it. I have a cellar with stillage for the casks that I keep at 50˚ and a cooler for the kegs which I keep at 38˚. They are both homemade insulated rooms with Sears air conditioners running through the outside wall. I buggered the air conditioners electronics to be regulated by a temperature controller. Variation on the controller is set at 2˚, which keeps the units from switching on and off too often.

            The pythons contain 3/8" ID beer lines and glycol lines. The glycol lines recirculate coolant through small Summit Racing Parts radiators. Temperature of the cask ale is around 53˚ +/- and the kegged beer is pouring at around 40˚. We have six gas taps, five of which pour a rotating selection of local micros and one of which usually has a cider or a perry. The ciders pour great. The beers are the problem.

            It is awkward at this point to measure the length of the python to the keg cooler, as it twists about the bar architecture, but I recall it being about 40 feet. I know that the cask lines contain about 40 ounces of beer, and the keg lines are about 5 feet longer. When it leaves the keg, it is 28" off the floor. It rises up to a chase that passes over the passage behind the bar. The high point is at 100", which it endures for about 40" before it drops down through one of the columns on the bar to a low point of 26". The height of the taps are 50". The tails for the taps are 1/4", so the lines, obviously, have adapters.

            Each beer line has its own regulator, but they are twitchy and it is hard to vary them by a single pound in an accurate manner. I currently have them set at 5 lbs. I have experimented with higher pressure, but just end up with more foam in the glass.

            The behavior at the tap results in beer flowing nicely for the first 8 ounces or so, after which it dumps heavy foam. The typical procedure for pouring a 20 oz pint is to grab two glasses and half fill each of them with beer, as the other half of the glasses will contain foam. Then we let it settle a bit, spoon off the foam, and merge the two glasses. Fortunately we don't sell a lot of keg beer, as the punters tend to want to devour real ale.

            Oh, and our elevation is 1200', if that matters.
            Last edited by BeerManWalking; 04-07-2009, 12:57 PM.

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            • #7
              Is it tight foam or does it have big bubbles? If the bubbles are big (like dish soap) then the pressure is definately too low. If you have high foam and tight bubbles, the problem is generally either temperature or high pressure. In some cases there may be turbulence stemming from foreign objects somewhere in the line.

              Combining 2 foamy beers - **shudder** - you might sell more draught beer if it was done properly.
              Last edited by einhorn; 04-07-2009, 07:40 PM. Reason: Clarifying a question

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              • #8
                Am I right in understanding you are pushing your beer with 5psi? If so, that is way, way to low.
                Scott Isham
                Harper's Brewpub

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                • #9
                  Bev Gas?

                  Any chance you can buy Bev Gas (Guiness Gas)? It's an in-tank blend of CO2 and Nitrogen. If so, you should be able to run around 25 PSI and pour well at 40 feet without over-carbonating. Another alternative is to buy a blender and blend the CO2 and Nitrogen yourself. As a ditch last option, you might use a beer pump on each line.

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                  • #10
                    Bubbles

                    They are tight, them there bubbles.

                    Just for a healthy supply of giggles, I turned one of the regulars from 5 to 20. The result was a faster supply of bubbles. However, in 5 minutes the bubbles settled down into a surprising amount of beer, although less than I would've liked.

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                    • #11
                      How long is the 3/16 inch line between the shank at the tap and the beer line(the choker). That line really needs to be 3/16ths and not 1/4inch. This is a key bit of info. I know it seems counterintuitive, but more pressure is the at least part of the answer when it comes to foaming. The problem with more pressure is soon the keg will be overcabonated, so that's why it's only part of the answer
                      Last edited by scott isham; 04-08-2009, 05:41 AM.
                      Scott Isham
                      Harper's Brewpub

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                      • #12
                        More Pressure + More Restriction

                        BeerManWalking

                        It definately sounds like you need to apply more pressure but you first need to restrict your lines with a longer 3/16" choker. I would begin there.

                        Regards,
                        Todd Malloy
                        Director of Brewing
                        Glenwood Canyon Brewing Co.
                        Glenwood Springs, Colorado

                        Comment


                        • #13
                          Line Reduction at the Taps

                          The 3/8" ID trunk line has a splicer that is 3/8" to 1/4" OD. See image. The length of the 1/4" ID line is around 8".
                          Click image for larger version

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                          • #14
                            1/4 is too big go with 3/16"

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                            • #15
                              choker line

                              for your run you should have about 3' of vinyl 3/16" beer line. assuming a carbonation level of around 2.5v/co2 your regulator pressure should be around 13 to maintain carbonation and give you enough push. also you should tape the choker lines to the gylcol lines to keep the beer cold as long as possible
                              Last edited by Brewerdennis; 04-13-2009, 05:08 PM.

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