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Thread: Hung Fermentation

  1. #1
    Join Date
    Jun 2006
    Location
    Florida
    Posts
    57

    Hung Fermentation

    3 days.... and finally it slowly is bubbling. I had to add yeast to get it there though. What do you guys think that the consequences are of this. I'm crossing my fingers that there aren't any!

    P.S.

    It was a brand new generation of yeast fresh from White Labs! I aerated it plenty and had good temps going in. I'm still puzzled at this one!

  2. #2
    Join Date
    Nov 2004
    Location
    Worcester, MA USA
    Posts
    32
    I suggest calling White LAbs directly, they have always addressed any questions immediately and with good information.

  3. #3
    Join Date
    Dec 2006
    Location
    Longmont, CO
    Posts
    13

    slow ferment.

    Check Your Mash Temps. If They Were Too High Then It Can Take A While To Ferment And Won't Finish Out. How Many Bbls Of Wort Were You Pitching To What The Yeast Can Handle. Expect Diacetyl And A Possible Unfinished Beer.

  4. #4
    Join Date
    Oct 2002
    Location
    Upland, CA, USA
    Posts
    53

    Consequences.....

    You will most likely end up with a higher pH and a little more autolyzed yeast/higher dead cell at the end of fermentation.

    This may or may not affect the flavor. Don't re-use the yeast from a stuck or lagging fermentation if you can afford not to!

    If you have access to a pH meter then check the pH of fermentation. If it is above 4.60 then you may want to consider dumpig it.... Pathogens can survive in beer if the pH is high enough, and the beer will have potential to make people sick.

    As far as reasons for the lag sometimes it just happens. It could be the yeast were kept cold too long before pitching or any number of other issues.
    Steve G

  5. #5
    Join Date
    Jan 2004
    Location
    St.Louis->Tacoma
    Posts
    633

    Cool Fresh White Labs Yeast

    In my experience fresh White Labs yeast can take extra time to get going, in fact i believe it says exactly this on the card White Labs sends out with the yeast. I second calling them, they have always been glad to answer any questions i have had.

    Jeff

  6. #6
    Join Date
    Aug 2005
    Location
    Nashville, TN
    Posts
    258

    Pathogens (WHAT>>>>>)



    SteveG wrote:
    >>Pathogens can survive in beer if the pH is high enough, and the beer will >>have potential to make people sick


    Steve, would you please explain, if possible in detail, of what pathogens you talk about and how/what make people sick????
    Looking forward to your reply.

    Fred Scheer

  7. #7
    Join Date
    Oct 2002
    Location
    Upland, CA, USA
    Posts
    53
    Quote Originally Posted by Fred Scheer


    SteveG wrote:
    >>Pathogens can survive in beer if the pH is high enough, and the beer will >>have potential to make people sick


    Steve, would you please explain, if possible in detail, of what pathogens you talk about and how/what make people sick????
    Looking forward to your reply.

    Fred Scheer
    Heya' Fred,

    Well, I guess I should have said first that it is extremely unlikely to get a pH that high as long as you still have plenty of CO2.

    That could only happen in the case of massive autolysis, which would give you a flavor issue anyway that would make the beer undrinkable anyway.

    This scenario shouldn't apply to the fermentation mentioned in this thread, since the fermentation in question actually seems to have started in under a few days.

    I only mentioned this because it was fresh in my mind from a grossly stuck fermentation (many weeks to finish and several days to start due to a stuck open glycol valve) we had where the pH was so high it became a concern. The stuff tasted awful.

    When beer pH gets too high (>4.6) it becomes susceptible to contamination from bacteria other than just beer spoilers, so if this beer got contaminated with some sort of anaerobic bacteria that could be harmful to humans, it could have potential to affect human health.....

    This scenario is unlikely to occur and is the reason why the Health Department is kind enough to leave breweries alone, so don't be too alarmed.

    As far as specific types of bacteria, I would have to check my sources. I do have a guy here that is a mycology expert that would have the answer....
    Steve G

  8. #8
    Join Date
    Aug 2005
    Location
    Nashville, TN
    Posts
    258

    Pathogens in Beer ???

    Steve:

    All bacteria, pathogen MO are quite acid, alcohol and pH tolerant; therefore it is most likely they canít survive in beer. Also, Hops prevent (through the Antibacterial compounds) MO to grow in beer through a higher bitterness. I did a research about 15 years ago, and found lots of bacteria in tavern serving beers out beerlines which where not cleaned, not to speak how the taps look.
    Although the bacteria do not necessary make a drinker sick, they affect the taste of the beer. Keep in mind that an atmosphere of almost 100% CO2 delays any toxin production, and if we consider the pressure in tanks, CO2 is lethal to almost ALL strains.
    Now, why is our beloved nectar an unfavorable medium for many MOÖdue the presence of ethanol (0.5 12% w/w), hop bitter compounds (between 13 Ė 100 ppm of iso-alpha acid), the mentioned CO2 content (~ 0.5% w/v), and the low pH (3.8 Ė 4.7), and we canít forget the extremely low content of oxygen( < 0.1 ppm). The traces of nutrient substances such as glucose, maltose and maltotriose also inhibit the growth of MO. We know that the latter carbon sources have been used up by our friend yeast during fermentation.
    Pathogens such as Salmonellae typhimurium and Staphylococcus aureus (to name a few..) canít live in beer because of the forgoing.
    Now, what can grow in beer? Beer spoilage bacteria are gram-positive, gram Ė negative bacteria, as well as wild yeast. Gram-positive bacteria include lactic acid bacteria belonging to the genera Lactobacillus and pediococcus. These are recognized as the most hazardous bacteria for breweries, and are reported for almost 75% of the microbial beer spoilage incidents. Now, I donít want to get further into the subject, but - I donít think that pathogenic bacteria will survive in beer. Iím also very careful to mention this in public forums, as Bacteria cause disease are called pathogenic bacteria and normally will result in an epidemic.
    I never heart of any pathogen bacteria found in beer (or fermentation) in my 35 years in business, and hop not to hear of any.

    Have a hoppy new year

    Fred Scheer

  9. #9
    Join Date
    Oct 2002
    Location
    Tadcaster, Yorkshire, UK
    Posts
    1,078
    Just to add to Fred's comments - I too have never heard of any pathogens growing in beer. We currently run an in house basic hygiene training session where we categorically state that no pathogens have ever been known to grow, due to the reasons mentioned. Foul tasting beer, hazy beer, ropey beer due to microorganisms, yes, of course. And of course you could get high levels of nitrosamines due to brewery bacteria, or poisoning from ergot - but thats another matter


    Cheers
    dick

  10. #10
    Join Date
    Dec 2003
    Location
    Lebanon, OR
    Posts
    18

    long lag phase and yeast transit times?

    Any chance that shipment was delayed in transit? We've gotten calls about stuck batches because of flight interruptions/unforeseen weather extremes.
    My wife, Linda, 'the microbioligist who must be obeyed' reminds me that yeast in transit should be considered unaccompanied minors, given a set of wings and a seat by the pilot. At least monitor via the tracking number. If high krausen is normal, you should be OK (at least for a blend)
    Best,
    Scott

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