Announcement

Collapse
No announcement yet.

Growler Issues

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Growler Issues

    Hello all,

    I have been experiencing an issue with our growlers going flat at an alarming rate, and want to know if anyone else has had a similar problem.

    A little background on me: I have been a commercial brewer for almost a decade, and have been in the industry as a whole for about 15 years. I have worked in every position/ at every level of the beer business from merchandising to designing a brewery. I have worked in over a dozen places that sell/ fill growlers, but I cannot figure out what is going on with the system at my current place of employ.

    We have a FOB draft system, first place I've ever worked that has one, and I feel like it might be the cause of the beer going flat in the growlers. When I say it goes flat quickly, I mean in less than two hours. As such, we have a good amount of growlers being sold here, but nearly zero people return to have them re-filled. I have tried every method of filling a growler, even the absolutely wrong way of just filling it from the faucet directly, nothing makes any measurable difference.

    I will happily supply any additional information to anyone that might be able to help me sort this out. Please reply if you have thoughts on the subject.

  • #2
    I have a fob system on a relatively short draw set up. No problems with Growler flatness and we just fill them with a tube from the faucet. Have you changed caps recently? Some of the caps tend to leak. We do stretch electrical tape all around the cap several times to seal it. Haven't had any problems.

    Comment


    • #3
      To go flat in 2 hours, it would have to be a huge leak. Is this a long draw system or a direct draw with the FOBs. The FOB itself shouldn't be the problem, unless the beer is coming out of the taps as foam. One of the things I have seen some of our customers do is have the wrong gas blend for the long draw system. I would bet that the beer coming out is probably close to flat already. Also, if you think its leaky caps, fill one of them then store it inverted, beer will leak out of the cap if there is a problem.

      Comment


      • #4
        It is a long draw FOB system. Our lines are about 90'-100' long. The beer poured out of the taps does seem to have some problems with head retention, and it isn't just the beers we produce in house. I tested a couple of different breweries' beers (that I have worked for in the past, and can verify exactly how they are originally carbonated), and got nearly the exact same results with the beers going flat very quickly. This is what led me to think it was the FOB system that was causing the problem...as the FOB's are the only variable of difference between the three breweries' systems.

        If it's a gas mix problem, how do I fix that? The brewpub I work for has gone through an entire management overhaul in the last few months, and there is no one currently working for the company when the FOBs were installed. Any advice would be helpful.

        Comment


        • #5
          My first hunch would be the gas mix - are you using pre-mixed tanks or separate tanks with a gas blender? I would check to ensure the mix is correct and not swapped (Will be system-dependant, but generally CO2 will be much higher proportion than N2). If the beers pour flat in the pint glass this high ratio of N2 could be decarbonating the beer as it's hooked up to the keg. Although this would still take some time and some headspace in the keg. Does the system foam a lot? Or pour exceptionally fast or slow?

          Comment


          • #6
            Originally posted by BemidjiBrewing View Post
            My first hunch would be the gas mix - are you using pre-mixed tanks or separate tanks with a gas blender? I would check to ensure the mix is correct and not swapped (Will be system-dependant, but generally CO2 will be much higher proportion than N2). If the beers pour flat in the pint glass this high ratio of N2 could be decarbonating the beer as it's hooked up to the keg. Although this would still take some time and some headspace in the keg. Does the system foam a lot? Or pour exceptionally fast or slow?
            We are using separate tanks with a gas blender. I have no idea on how to check to see if the mix is correct...probably have to call our gas guys. The system doesn't foam almost at all (probably due to the fobs) but it does pour significantly faster than other places I have worked.

            Comment


            • #7
              If you don't know what your gas mix ratio is, you have no way to keep your carbonation correct. Most mixes are either 70-30 or 75-25 N2/CO2.

              Use your P/T chart to determine the CO2 pressure required to maintain your level of carbonation at your cooler temp. Then multiply that pressure by the inverse of the ratio of N2 to CO2 in your mix. For instance, our beer is carbed at ~2.5 v/v. At 40 F, that requires 12-13 psi of CO2. To get 13 psi of CO2 from a 70-30 N2/CO2 mix, that requires 2.3333 X 13 psi or ~30 psi of mixed gas. You then need to balance your lines for this pressure by adding restriction immediately before the faucets.

              I'll bet you're serving nearly flat beer, which is why the growlers are completely flat after the headspace balances out.
              Timm Turrentine

              Brewerywright,
              Terminal Gravity Brewing,
              Enterprise. Oregon.

              Comment


              • #8
                Timm successfully explained where I was going! I am suspicious that your beer is flat prior to going in the growler. And perhaps by pouring more aggressively than it ought to you are creating some "false" carbonation and foaming in the glass that is passable if the consumer drinks the beer immediately, but is quickly apparent if it sits for a few minutes or ends up in the growler.

                Comment


                • #9
                  That is very helpful advice. I am gonna get with our gas guys tomorrow to fix this problem. Thank you all. I'll let you know how it goes

                  Comment


                  • #10
                    So, I talked to our gas guys a little bit ago, and I have more information but also more questions; specifically for Timm and Bemid.
                    Our gas blend is 60/40 N2/CO2. Our regulators on the draft system are set at 25psi,and the cooler temp runs between 38-42 degrees F.

                    So, if I work the math in reverse from those numbers, it'll tell me how high to carbonate our in-house beers right?

                    25psi/ (60/40) = 16.667
                    16.667 @ 40 degrees = is almost 2.9v/v

                    That seems incredibly high. Can that be right?

                    I've never carbed any beer that high.

                    Comment


                    • #11
                      Having no idea what your desired carb level is, nor the temperature of your cooler, there's no way of telling. Your math is correct, so figure out the proper CO2 pressure for your carb level and cooler temp, then run multiply by 1.5 to get the proper pressure for your mix. In my example above, 2.5 v/v and 40F, my pressure would be right about 20 psi.
                      Timm Turrentine

                      Brewerywright,
                      Terminal Gravity Brewing,
                      Enterprise. Oregon.

                      Comment


                      • #12
                        I prefer to stay in the 2.47-2.56v/v range for my beers, and the cooler temp is averaging about 40 deg F.
                        So for the sake of easy math, let's call it 2.5v/v so that's about 12.5psi.

                        Meaning I need to turn my regulators down to 19psi to achieve the correct balance? right?

                        Comment


                        • #13
                          My math or understanding of the conversation may be off...but if you are running 25psi with 60% N2 and 40% CO2 then your CO2 concentration is essentially at 10psi...40% of 25psi.

                          10psi @ 38°F = 2.3 Vol/CO2
                          @ 40°F = 2.2 Vol/CO2
                          @ 42°F = 2.1 Vol/CO2

                          These carbonation rates are on the low side, but probably wouldn't be perceived at "flat."

                          It seems that any scenario that calculates out to his system overcarbonating his beers (hence having to lower the pressure) wouldn't apply being the beer is objectively flat.

                          Please correct me if I'm wrong on this!

                          Jeff, are you able to confirm the carbonation in the brite or unitank to ensure that the beer is entering the keg at a known carb level?

                          Cheers,
                          Tom
                          Last edited by BemidjiBrewing; 12-20-2017, 11:52 AM.

                          Comment


                          • #14
                            That sounds about right. I prefer to go about 1 psi high just to be on the safe side.

                            Now you'll need to be sure your delivery system is balanced for that pressure. The Draught Beer Quality Manual is a great resource for anything related to serving beer, including line balancing. It's also a free download.
                            Timm Turrentine

                            Brewerywright,
                            Terminal Gravity Brewing,
                            Enterprise. Oregon.

                            Comment


                            • #15
                              Originally posted by BemidjiBrewing View Post
                              My math or understanding of the conversation may be off...but if you are running 25psi with 60% N2 and 40% CO2 then your CO2 concentration is essentially at 10psi...40% of 25psi.

                              10psi @ 38°F = 2.3 Vol/CO2
                              @ 40°F = 2.2 Vol/CO2
                              @ 42°F = 2.1 Vol/CO2

                              These carbonation rates are on the low side, but probably wouldn't be perceived at "flat."

                              It seems that any scenario that calculates out to his system overcarbonating his beers (hence having to lower the pressure) wouldn't apply being the beer is objectively flat.

                              Please correct me if I'm wrong on this!

                              Jeff, are you able to confirm the carbonation in the brite or unitank to ensure that the beer is entering the keg at a known carb level?

                              Cheers,
                              Tom
                              Yes, we carb at 18-20psi and check it hourly with our Zahm until we get to our desired v/v

                              Comment

                              Working...
                              X