Ask The Brewmasters

  • 1.  Extreme Colloidal Instability

    Posted 06-10-2022 17:54
    Hi,

    We recently experienced what looks to be an extreme protein / polyphenol complex in one of our beers that we have never seen at this level before. Please see attached pictures. Looking for some thoughts on why this particular batch could be such an outlier. Some details from throughout the processing:

    Brewhouse -
    • No changes to grist composition or milling technique.
    • The specific lot of base malt used in the batch in question had protein at 11.08, soluble protein at 5.32 and a very high reported S/T of 51.7. FAN was 227. 
    • Lautering proceeded as normal
    • Normal kettle fining regiment with Whirlfloc
    Cellar - 
    • Normal procedures were followed with multiple cone drops to remove yeast and hop material pre centrifugation. 
    • This brand is dry hopped but under a microscope the material we are seeing is not hop particulate. 
    • Centrifugation occurs through a rough centrifuge to a surge tank then to a polishing centrifuge. 
    • Brite tank is analyzed for EBC and ASBC both of which came out at or below spec. 
    • DO was in spec and the tank was not scrubbed.
    • The beer is not conditioned with anything, yeast or Kraeusen. 
    Packaging - 
    • Product was put into kegs and cans. In-line turbidity meters throughout the runs did not indicate any issues. 
    • Both cans and kegs are showing the issue and it's not isolated to the beginning or end of a packaging run. In other words, some samples from the middle of the run have shown this phenomenon too.

    The beer is a month old at this point. When it was fresh it did not display this behavior. 

    Also of note, is that temp cycling the beer might be exacerbating the issue. Comparing some samples that went from warm to fridge temps with those that went from warm to freezer then back to fridge, gave different intensities of breakout. 

    Curious is anyone has experienced anything like this. 

    Thanks in advance for any insights or suggestions,

    ------------------------------
    Scott Birdwell
    Manager of Brewing Operations
    Deschutes Brewery
    Bend OR
    (541) 385-8606
    ------------------------------


  • 2.  RE: Extreme Colloidal Instability

    Posted 06-13-2022 13:56
    When we released our first Hazy in package, we had complaints for floating contaminates which turned out to be poly-phenol complexes.  We lowered our Turbidity specification, essentially pulling more out.....which eliminated the complaints.    

    About a month or two ago, we recieved a rash of complaints out of nowhere for the same issue.    We knew the protein level of our Malt at the time was elevated (12.0 - 12.5), the FAN was elevated as well.   We have been able to confirm this is happening in package, and after talking to our Malt supplier the most likely cause from the COA reported results on our end was Protein.    The Malt of concern for us was 2-Row, your level of protein has me believing this most likely related to the excess FAN.

    We have been running a stability study to better understand how long this takes to develop for us in package.   In doing this, we have identified a 50-75 NTU difference between a cold and warm sample packaged on the same day.  This was initially confusing, but after sitting with it for a while, I believe it is just clear evidence that some of the haze in our Hazy products is just plain old chill haze.   I am confident that is also what is driving your temperature created variation in breakout.


    The raised FAN, and S/T are very interesting to me as those are the common elements between our observations and yours, and I am now thinking that is a better indicator for biotransformed haze stability

    ------------------------------
    Chris Mehr
    Director of Quality
    Revolution Brewing
    Chicago, IL
    cmehr@revbrew.com
    ------------------------------



  • 3.  RE: Extreme Colloidal Instability

    Posted 06-13-2022 23:53
    Hey Scott,

    Some things that come to mind as I've experienced this a few times and yes, the haze forms in package. You should also find quite a bit of good info searching this discussion board as well.
    1. When was the last time you optimized kettle finings? This can have quite an impact!
    2. What temps do you chill your beer prior to centrifugation?
    3. Have you considered the use of enzymes to solve this issue?

    Beers,

    Aaron






  • 4.  RE: Extreme Colloidal Instability

    Posted 06-14-2022 03:59
      |   view attached
    Thanks Chris and Aaron for your thoughts. To answer some of Aaron's questions, yes we are going through more optimization trials with kettle finings, always a good move! Our tanks are cooled to <32 F (set point of 30 F) for a minimum of 48 hours which we just recently bumped to 72 hours. However, in reality many tanks spend more than 48 hours below 32 F naturally just due to when they fall in line on the production schedule. The beer in question had 70 hours of conditioning time. No we have not gone the enzyme route yet. 

    A couple other observations. One, our coarse centrifuge had a very hard time processing this tank with the first several hours spent discharging every couple minutes and big swings in flow rate. Second, some more experimentation with temperature gave some interesting results. The attached picture is from one of our QA library samples that had been sitting in our warehouse (storage temp of ~50 F) since packaging in May and was then chilled down for 48 hours and poured. Another can from the same six pack was poured (not pictured) without being chilled and did not show any particulate. Certainly we have had less than desirable particulate in beers before but nothing near this magnitude.

    ------------------------------
    Scott Birdwell
    Manager of Brewing Operations
    Deschutes Brewery
    Bend OR
    (541) 385-8606
    ------------------------------

    Original Message


  • 5.  RE: Extreme Colloidal Instability

    Posted 06-14-2022 14:51
    Nice photo Scott

    It is reminiscent of the "Frozen Beer" syndrome that appeared in lager beers after consumers purchased beer in the Canadian winter, then was returned to the lab as a customer complaint.  This happened more often at temperatures below -25 F. after the customer forgot the beer in the trunk of their vehicle during extreme cold.... with the resultant gobs of protein (as determined by eosin yellowish stain) very similar to your photo.

    This particular cold weather freezing effect was far beyond the conditions of the typical 72 hour 320F Chill haze test.  I can remember back in the 80's that we tried to reproduce the protein break by freezing beer in lab freezers but were totally unsuccessful. 

    Remember that I am describing physical changes in typical malt/adjunct lager beers that had cold conditioning, and great protein control with 310 F filtrations through DE filters, centrifuges, and Warm/Chill hazes of less than 60 FTUs.  Whereas Craft beers with dry hopping, hop creep, unusual malts and adjuncts, fruits etc can create unknown physical, chemical, and biochemical problems.

    Good luck with that problem.  Interesting

    Jim

    ------------------------------
    James Holden
    Brewing Consultant
    Retired but Busy
    jholden007@hotmail.com
    Canada/US/Mexico
    ------------------------------

    Original Message


  • 6.  RE: Extreme Colloidal Instability

    Posted 06-14-2022 17:35
    A caution Scott

    Others have recommended blending the stalled and cold brew with another separate and divided brew to warm it up the first.  I would not suggest that you don't do that.  It' puts another brews sensory profile in jeopardy.  Better having one brew to blend off rather then adding one more brew to the problem.  Blending is risky business if your products tend to be consistent and your customers expect the same flavours every time.  The large breweries would normally blend at 10%.

    Jim

    ------------------------------
    James Holden
    Brewing Consultant
    Retired but Busy
    jholden007@hotmail.com
    Canada/US/Mexico
    ------------------------------

    Original Message


  • 7.  RE: Extreme Colloidal Instability

    Posted 06-15-2022 11:18

    Hi Scott,

     

    I saw your post a couple of days ago and have some thoughts that might be helpful.  First, the S/T level at 51.7% is incredibly high (well modified malt should be in the range of 42-43%) and is most likely due to the worst malting barley crop (2021) in recent memory- my memory goes back 40 years and I have never seen such a poor crop.  A perfect storm of heat, drought and then rain at harvest has maltsters scrambling to provide usable malt to brewers this year.  Maltsters have two main methods to control malt quality and they both have to do with germination.  They can germinate longer to reduce beta glucan/gums, but this causes an increase in soluble proteins.  If they go lighter on germination, then the reverse occurs.  The malt you are seeing is an effort to reduce BG at the expense of producing higher soluble protein.  You didn't mention the BG levels but I suspect they may not be good even with the elevated S/T.  Haze is formed by small bits of soluble proteins rich in the proline amino acid.  FAN is composed of an assortment of amino acids that are (mostly) consumed by the yeast, but do not form haze.  A FAN of 227 is not a particularly high level, and should be ample for the yeast, without causing other problems. 

     

    Second, Haze forms between soluble proline-rich proteins and oxidized polyphenols.  Polyphenols can come from malt and hops.  I am guessing this is a well hopped IPA, and will have lots of hop polyphenols.  So you have the two prime ingredients for chill haze in abundance.  The haze will start to form at under 4.4 C (40 F) and will be most optimized at about -1.1 C (30 F).  Even with cold conditioning, since you don't use any chill-proofing agents, there will be plenty of these components that make it through the centrifuges.  You may not see haze formation until packaging, when residual polyphenols oxidize and are now able to form haze with the residual proteins. 

     

    The reversible chill-haze will eventually be become permanent.  Now that the beer is in cans and kegs, there is really no remediation (except possibly renaming it integrating the word "hazy"). 

     

    I see a couple of pathways to deal with the poor malt we will all continue to see this year, and specifically issues with either (or both) high soluble proteins and high BG:

    • Start by consulting with your base malt supplier, let them know the issues you are experiencing and discuss available options. 

    Other brewing process options include:

    • Avoiding a protein rest in the mash, you don't need any additional FAN, and the low temp rest will exacerbate the soluble protein problem.
    • Chill-proofing can be accomplished with silica gel products, as well as an AN-PEP enzyme products, which both target proline-rich proteins and will reduce or eliminate the haze.
    • Ask your malt supplier to cut down on the soluble proteins (reduce germination) and then address the higher BG with a beta-glucanase/xylanase enzyme product in the mash, which effectively breaks down beta-glucan along with other barley gums. 

     

    MBAA member Alister Pringle used to lecture on this topic at the Malting and Brewing Science course in Madison, and is good resource.  Perhaps he will weigh-in on the thread because the malt produced from the 2021 crop year will be similarly problematic for everyone.  

     

    Cheers,

     

    Karl

     

    Consulting Brewer

    Karl Ockert Brewing Services LLC

    www.ockertbrewserv.com

    Cell:  503-887-1938

     




    Original Message


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