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  • lager yeast won't floc inside fermenter, but...

    I am having a problem. After 10 weeks of conditioning, the beer (lager) won't turn clear. Today's yeast volume reading is 20 million/ ml. However, if I pour it into a sample glass, yeast will settle immediately (in 10 minutes as I can see them at the bottom of the glass.) It will turn clear overnight. Yeast count drops to 5 million / ml. Why?

    here are some the parameters:

    yeast strain: unknown. (the same yeast flocs pretty well couple batches ago, I know this could be an older generation, but if it is old, it should not floc in the glass so quickly. )
    beer: brown lager
    temperature is 2.5-3C ( ~38F).
    batch size (2.5 T conical fermenter, 3.5 meter high. ~ 10 foot)
    OG. 1.050
    FG, 1.010. (as of today, didn't change for the past month, so I assume it is final.)
    pH: 4.1 (no change for a month)

    I have tried shocking the beer with CO2 flush, didn't reduce the yeast suspension.

    Any explanations and suggestions? I am considering adding CaCl2 solution or fining.

  • #2
    Can't say I have any flashes of brilliance here, but a couple of thoughts:
    1. I suspect it may be too late to add Ca and improve yeast health, thereby getting better flocculation. I think they have to incorporate the Ca with food.
    2. I would go for finings first. If that does not work, you could always try the CaCl (or CaCO3, depending on your water and whether you are going for a malty or hoppy profile) later.

    Good luck. Let us know what works.
    -Lyle C. Brown
    Brewer
    Camelot Brewing Co.

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    • #3
      If we keg the beer, and left the keg at room temp, the beer can floc very well in couple days and at the bottom of the keg the yeasts settled into a large cake. No pressure change between the fermenter and the kegs. So, as an indicator to a possible solution, we have tried increasing temperature to 10C inside the fermenter for couple days, and.................

      it didn't work! SOB!

      Now we are preparing isinglass, will report on this.

      Comment


      • #4
        Sounds like you already looked under a microscope, but are you sure it's yeast and not chill haze?
        __
        Kushal Hall
        Common Space Brewery
        Hawthorne, CA

        Comment


        • #5
          more fun with lager yeast

          and I thought I was alone on this one. I have seen very similar results with lager yeast. Re-pitching seems to bring this about.

          So I was thinking..could these be accumulated respiratory deficient mutants (ie pettiet mutants) smaller yeast...slower floc.

          Or could the yeast have mutated to a non-flocculent strain, ie lost its flo genes due the stress of repitching.


          On re-pitching lager yeast I have found the best (floc) results by doing the following

          1. keep on ice after harvesting
          2. Re-pitch within 24 hours of harvesting (or feed and aerate yeast)
          3. Aerate wort, make sure there is enough ca+, FAN (free amino nitrogen), and so on in the wort.

          Comment


          • #6
            circulation

            You may have chaotic circulation going on in your tank, preventing a nice even sedimentation.

            Comment


            • #7
              Can't hurt to crash it to 32.
              Joel Halbleib
              Partner / Zymurgist
              Hive and Barrel Meadery
              6302 Old La Grange Rd
              Crestwood, KY
              www.hiveandbarrel.com

              Comment


              • #8
                Originally posted by BrewinLou
                Can't hurt to crash it to 32.
                I agree here, get it real cold. Maybe they just don't know it's winter!!

                Comment


                • #9
                  Kushal, no, it's not cold haze, i actually saw the creamy yeast at the bottom of the glass.
                  Sulfur: We only crop yeast frequently, and there has been no other disturbance for a month or so.
                  32F has been reached for couple days, didn't work.

                  The intriguing part is: Why the beer flocculated so fast once it left the fermenters? If it is because of the mutated yeasts, should the beer stay fuzzy when it is removed to another container?

                  Should lower pressure help flocculation? Now I just realized kegs' pressure is lower than that of the tanks.

                  Comment


                  • #10
                    is the volume the same as your other beers? If it's less, maybe you're not getting even cooling because your upper glycol zone is not covered (assuming you have one). In that case, you only have the lower cone zone cooling and could have some type of layering action going on with different temp profiles.

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                    • #11
                      rack it

                      Sulfur has already posted what I am thinking that you might have convection going on for whatever reason. Rack the beer and let it settle in another fermenter or kegs and then rack again. Be sure and post your results for the enquiring minds that want to know! Good luck!

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                      • #12
                        elaborate

                        Yeast is still suspending as of today. However, brown lager floc pretty well, yeast now is 5 million/ml. Pilsner is still high, but has reduced from 50 million to 25 million/cell.

                        I can understand racking, and settling, but why rack again after that? hmmm. let me know. I will rack the beer.

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                        • #13
                          I am wondering the same thing. I had a lager that stayed at 32 for over 6 weeks. It was still loaded with yeast when I filtered it. The other day I tried something. I hooked a CO2 line to the sample port and pressurized the tank. While it was filling the temp went down to 26 degrees. I have since raised all my tanks to 35 instead figuring that I have a layering problem at that low of a temp.
                          Mike Pensinger
                          General Manager/Brewmaster
                          Parkway Brewing Company
                          Salem, VA

                          Comment


                          • #14
                            The reason of not precipate

                            After months of trying and failing, now we have the following conclusion.

                            The yeast needs to be propagated every batch! If we use freshly propagated yeast, the fermentation can be done in 10 days with good precipitation. (lager yeast, 13 P down to 2-3 P at 12C, D-rest at 14 C). Even the first generation cone to cone pitching at 20 mil/ml still didn't do the job -- slow fermentation and heavy yeast suspension. However, the freshly propagated yeast works well even when it is pitched at 12 mil/ml rate.

                            Hope someone can tell me why.

                            Comment


                            • #15
                              Originally posted by chaosmaster
                              After months of trying and failing, now we have the following conclusion.

                              The yeast needs to be propagated every batch!
                              Cannot tell you why, but I can make a recommendation. Spank that naughty yeast right out of your brewery, and get a better-behaved new strain in.
                              Gregg

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