Ask The Brewmasters

  • 1.  Nitrogen keg purges

    This message was posted by a user wishing to remain anonymous
    Posted 09-26-2022 13:25
    This message was posted by a user wishing to remain anonymous

    Is anyone using nitrogen for final purge on automated keg lines? 

    Lots of TQ literature (mostly older) on using nitrogen to purge tanks, push product, but I could find no reference to keg purge/filling. My concern is that with the higher pressures associated with counterpressure filling  on our keg line we might see some small amount of nitrogen dissolving in the beer resulting in foamy pours.



  • 2.  RE: Nitrogen keg purges

    Posted 09-27-2022 14:08
    There is an MBAA webinar on the subject from March 2021 in the archives.  My understanding is that you couldn't easily use nitrogen for keg purging for a couple of reasons.  Most even "high purity" nitrogen still contains enough O2 to cause DO spikes in beer.  Also, Having nitrogen in the headspace instead of CO2 would cause unstable co2 in solution due to partial pressures and gas laws.  The CO2 in the beer will come out of solution and enter the headspace until equilibrium is reached.  You may be able to use a mix of CO2 and Nitrogen, but I've never tried it personally.

    Use for tank purging, product pushing and such is debatable depending on who you talk to.  Someone here may be able to chime in with first hand experience.

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    Jason Weihbrecht
    GM of Brewery Operations
    Oskar Blues Brewery
    Brevard NC
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    Original Message


  • 3.  RE: Nitrogen keg purges

    Posted 09-27-2022 14:08
    Purging kegs with Nitrogen (N2) - My old company Burnett & Rolfe Ltd, UK were among the first to use pure N2 to purge and counterpressure kegs prior to filling, around 1970 at the Ansell's Brewery in Birmingham. That is relatively simple to do at the time of kegging the product by raising the counterpressure in the keg from a nominal 15 PSIG of CO2 to approximately 35 PSIG of N2. Unlike CO2, N2 does not infuse into a liquid but will forever remain as micro/nano bubbles in solution all the while the pressure is maintained. That is where the problem begins at the bar for dispensing. Many faucets in operation in bars are free flow faucets, to dispense a product saturated with approximately 15 to 20 ppm of N2, you must use a good quality restrictor faucet and teach the bar person how to dispense correctly - Similar to dispensing Guinness. When done correctly, the product in glass looks great, it will have a tight creamy head and a fantastic lacing on a "beer clean" glass and just sufficient N2 to give a slightly softer mouth feel.

    Good luck,

    Jeff.

    Jeff Gunn
    President & CEO
    IDD Process & Packaging, Inc.
    5450 Tech Circle
    Moorpark, CA 93021
    Toll Free: 800-621-4144
    Tel: 805-529-9890
    Fax: 805-529-9282
    Cell: 805-444-3842
    Web Site: www.iddeas.com



    Original Message


  • 4.  RE: Nitrogen keg purges

    Posted 09-29-2022 11:22
    For a couple months now, we've been using N2 instead of compressed air during our "air purge" cycle (after detergent and water rinse on an iDD Squire Plus 2), and saw a noticeable decrease in DO levels. We're still performing a final purge with CO2. To Jason's point, we've yet to measure the carbonation level of kegs after a storage period; however, our carb levels rarely differ from tank readings immediately after filling and we've yet to receive any quality reports from market. The only downside to this process for us is the cost of high purity N2, as we go through a 50 L tank every 60 ½bbl shells.

    You may want to consider auditing the purity of your CO2 supplier as well, if DO pickup is of concern.

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    Jeremy Pryes
    Founder & HeadBrewer
    Pryes Brewing Company, LLC
    Minneapolis MN
    (612) 787-7937
    ------------------------------

    Original Message


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