Ask The Brewmasters

  • 1.  Gushing Cans - Dry Hopped Brands Only

    This message was posted by a user wishing to remain anonymous
    Posted 06-17-2024 21:22
    This message was posted by a user wishing to remain anonymous

    Hi all,

    Over the last year and a half, we have experienced a significant uptick in gushing cans weeks after filling.  I'll outline as much information as I can to avoid guiding folks down the wrong track, as well as some of our avenues of exploration.

    We've struggled significantly on replicating the issue in the lab.  We get consumer complaints but are unable to pull library product and experience the same issues.  After speaking with a few collogues at other breweries, I was pointed toward a publication about "Winter Gushing" which outlines an idea that beer stored at room temperature for 1-3 months, chilled, then immediately opened has a higher potential to gush, especially when the beer is stored horizontally.  Much of the article attributes this to the enzyme papain.  Unfortunately, we have not been able to produce gushing cans after replicating the storage conditions outlined in the article.  At this point, any theory is a good theory and we'd be very appreciative of the help figuring this out.

    Presentation:

    1. So far, this has only been found in our dry hopped brands.
    2. When opened, the can foams over.  Not explosive, but steady.
    3. The can continues to foam longer than expected, multiple seconds.
    4. Once foaming stops, about half of the beer remains in the can.

    Raw Materials:

    1. There are little to no commonalities between affected brands.
    2. Some are pale malt based brands, some are pilsen malt based brands.
    3. There are no shared hop varietals or lots between all affected brands.
    4. Brewbrite is used for our dry hopped brands only.  About a year and a half ago, our supplier transitioned us from a powdered brewbrite to a granular brewbrite.  We will be investigating usage rates for a second time as part of the effort to solve this issue.

    Microbiology:

    1. First thought was of course diastaticus.  However, we were able to produce a gushing can in the lab one time, and it came back clean on our PCR screens.
    2. If we're able to produce another gushing can in the lab, we will be plating on general media to investigate any non-spoilage organisms that may be present and not targeted by PCR.

    Packaging Conditions:

    1. Cans run on a KHS filler max speed 315 cpm.
    2. Ionized air purges cans prior to filling.
    3. Counterpressure gas is CO2.
    4. Underlid gassing is nitrogen from our nitrogen generator.
    5. 12oz standard 202 cans (Ball).

    Other Brainstormed Avenues of Investigation:

    1. Calcium oxalate.
    2. Hop creep.

    Thank you all in advance for any input you may have on this.  Looking forward to hearing some theories!



          • 2.  RE: Gushing Cans - Dry Hopped Brands Only

            Posted 06-18-2024 13:48

            Hi,

             Given it's dry hopped beers, check for hop creep. If you can look for increased ethanol, increased CO2, and/or lower residual sugars, that's where I would start.

             Just to be sure, open a few cans, carefully decant most of the liquid, if you can, filter that portion and check filter under a microscope. In the can, check for sediment, and inspect the can liner for any damage. If there is sediment, examine under a microscope for a possible ID; crystalline, micro, or skins from collapsed bubbles. 

            Best of luck solving this. 

            Cheers,

            Kevin



            ------------------------------
            Kevin McCabe, PhD
            Founder
            Double Strand Consulting
            kevin@doublestrandconsulting.com
            https://www.doublestrandconsulting.com/
            ASBC Alternative Beverage Subcommittee Chair
            ASBC Technical Committee
            MBAA Webinar Committee Chair
            TTB Certified Chemist
            ------------------------------



          • 3.  RE: Gushing Cans - Dry Hopped Brands Only

            Posted 06-18-2024 15:37

            Given you mention this is exclusive to dry-hopped beers, I agree with Kevin that checking for hop creep would be a great first step and is fairly straight forward. An increase in can CO2, decrease in apparent extract, or increase in VDK would be easy indicators that hop creep has occurred. If that is in fact the issue, there are a number of good resources related to managing hop creep. If you want specific guidance, I'd be happy to share our takeaways from chasing this down. 

            If that is not the issue, another thing would be to assess if you've had a change in haze or haze formation in package. I mention this as we had some gushing issues (albeit less aggressive than you mentioned) in a few brands that we could only trend with a decrease in package haze stability. The beer went through a period of significant chill haze issues that we finally tracked back to poor hotside trub formation and thus carryover into fermentation. We spent some time working on finings optimization as well as hop additions and were able to improve clarity and shortly after the gushing went away.  

            We are running a very similar canning operation to you, including using generated N2 on our seamer. I'd be interested to know if that leads you down any interesting rabbit holes. I'd also be interested in connecting to share best practices with running N2. If you're able, message me to connect further. 

            Cheers,
            Campbell



            ------------------------------
            Campbell Morrissy, PhD
            Director of Brewery Operations
            pFriem Family Brewers
            ------------------------------

            Original Message


          • 4.  RE: Gushing Cans - Dry Hopped Brands Only

            Posted 06-20-2024 13:15

            Thank you all for the feedback.  Hop Creep seemed to be one of the most obvious scenarios, and I'm glad there is some consensus there.  We'll be looking into changes in diacetyl, ABV, RDF, extract, and haze over time.  We'll test weekly on one of our slower moving dry hopped brands in the tank, and also pull cans to test weekly and store them at both cold and warm (90 degree) temperatures.  Based on what we've seen in the field, if hop creep is indeed the culprit, we should be able to affirm so within a month or two.

            I'll report back on our findings.  Thanks all for your input!



            ------------------------------
            David Martin
            Quality Assurance Manager
            Alaskan Brewing Company
            Juneau AK
            (907) 780-5992
            ------------------------------

            Original Message


          • 5.  RE: Gushing Cans - Dry Hopped Brands Only

            Posted 06-18-2024 14:05

            I personally do not know the answer, but I bet Travis Audet of Slant Six Consulting may be able to help you determine the root cause of the gushing problem of dry hopped beers.



            ------------------------------
            Dana Johnson He/Him
            Sector Specialist, Craft Brewing
            Diversey - A Solenis Company
            Henderson, CO
            800.233.1000
            ------------------------------



          • 6.  RE: Gushing Cans - Dry Hopped Brands Only

            This message was posted by a user wishing to remain anonymous
            Posted 06-18-2024 15:36
            This message was posted by a user wishing to remain anonymous

            Hello Fellow Brewer, 

            My jaw dropped when I read about your gushing issues.  You aren't alone in this.

            We've been dealing with a very similar situation:

            Our dry hopped brands are, sporadically, at risk of gushing after being in cans for 2.5 months.  The most common complaints are about 3 to 5 month old cans.  Just as you found, we cannot force our lab retainers to gush.  We ruled out secondary yeast fermentation, no bacteria were present, and no calcium oxalate or other unusual sediments were identified in spin downs.

            The only literature we were able to dig up, that resonated with our experience, is the same "Winter Gushing" paper you found! 

            The notable differences between our situations are that we don't use Brew Brite, we clarify with centrifugation only and we occasionally receive gushing complaints about a non-dry hopped brand.

            We also run an ionized air can purge and a KHS can filler (at about the same speed!) but use CO2 for both can purge and underlid injection.  For a brief time, we used underlid N2 but that did not seem to correlate to gushing at all.

            A total metals analysis of wort has identified elevated levels of iron ~0.5 mg/L which has made me wonder about iron precipitates in beer being responsible for gushing but the iron concentration in canned beer is much lower: <0.05 mg/L. Magnesium is also high (this has been traced back to the malt itself), manganese is also higher than I would like.  Brewtan B seems like it might be a good option for sequestering these metals which are likely catalyzing staling reactions.  Anyone know if elevated wort metals could be related to gushing?

            Regards,

            Stanley




          • 7.  RE: Gushing Cans - Dry Hopped Brands Only

            Posted 06-21-2024 18:26
            Edited by Andy Tveekrem 06-22-2024 13:59

            I'd like to offer one other thought as I've experienced this in the past as well: Yeast health and autolysis could be a factor. Here's a paper from the wine world regarding yeast autolysis and foam quality for sparkling wines that may be of interest: https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1755-0238.2006.tb00051.x

            [edited to add: Heavy hopping affects the beer pH and may make the environment less healthy for your yeast. pH adjustment could help as well. Dry Hopping could be a Red Herring making us think of Hop Creep before Yeast Health]. 

            I also recall this coming up in the threads a bit ago. You can take a look by searching the forum for "Gushing Potential" with posts around 10-15-20. Many responses highlighted Calcium Oxalate as a potential culprit, though at least one respondent experienced the issue independent of oxalate formation. 

            I'd say over attenuation/hop creep would be easy to evaluate and a good place to start. If that doesn't solve your woes, maybe upstream yeast support like calcium and zinc could help. Added bonus with calcium can be the earlier sedimentation of oxalate crystals. I can provide some more of my experience with this if you head down the autolysis path. 

            Keep us updated!

            Cheers!

            P.S. I have follow up questions too if you're so inclined to answer...

            • Are these only in cans? Any foaming issues on draft or in bottle?
            • Any packaging formats stored on their sides?



            ------------------------------
            josh waldman
            lead brewer
            cloudburst brewing
            seattle, wa
            ------------------------------



          • 8.  RE: Gushing Cans - Dry Hopped Brands Only

            Posted 07-04-2024 18:43

            Hi,

            you received a lot of information on the chemical side.

            Myself as a microbiologist, I am guessing that you could have a low concentrated contamination with Dekkera/Brettanomyces yeasts. Did you test PCR only for diastaticus or did you test for Brett, too? Brettanomyces yeasts are very common in the environment, especially on fruit and plants, could be introduced to the beer on the hops which you are using for dry hopping. Another potential source are fruit flies which are harboring a lot of Brett yeasts in their intestines and are a common contamination source, too. A Brett contamination in packaged beer is typically starting in the warmer months of spring and summer, but can take 3-6 months without any hint of irregularities in the packaged products until suddenly over pressure appears. Therefore, the complaints from customers typically appear from mid summer to late autumn.

            I'd advise to test for Brettanomyces yeasts, you can even check the hops before you use it for dry hopping.

            Feel free to contact me direct if you want to discuss this issue any further,

            Gudrun



            ------------------------------
            Gudrun Vogeser
            Founder & Owner
            PIKA Weihenstephan
            Pfaffenhofen, Bavaria
            +49 8441 8794830
            ------------------------------



          • 9.  RE: Gushing Cans - Dry Hopped Brands Only

            Posted 07-09-2024 18:35

            Thank you for the feedback!  We have indeed tested for Dekkera/Brett via PCR, and everything has come back clean.  We also just plated a few gushing samples on YM agar that returned no growth as well.



            ------------------------------
            David Martin
            Quality Assurance Manager
            Alaskan Brewing Company
            Juneau AK
            (907) 780-5992
            ------------------------------

            Original Message


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