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  • Flocculation issue

    So I've got an interesting floccing issue. We have taller 7 bbl fermenters with a 45 degree cone. Beers tend to be cloudy after crashing to 32 degrees even with high floccing yeast. We have 30 bbl fermenters that are wider and have 60 degree cones that will clear out completely when crashing to just 55 degrees, so after a lot of research I attribute this cloudiness in the 7 bbl fermenters to tank geometry. We use biofine clear, about 200 mL for the 7 bbls, and sometimes the beer will clear up, sometimes it won't. But without fail, if we keg the beer and put it in our cooler which has an ambient temp of 40 degrees, it will clear up in about a week.

    We have a good vigorous boil and tend to knockout into the fermenter clear. We are at about 150 ppm for calcium. Per suggestion from a few yeast suppliers, I've bubbled CO2 into the fermenter post fermentation/pre-crashing to knock yeast back into suspension to try and grab more cells, but haven't had any luck changing the situation. So I'm at a bit of a loss. Are we damned by tank geometry, or is there another option? I know CO2 can aid in cell binding, should I try to bubble CO2 through the fermenter near the end of fermentation to encourage more binding? Obviously I won't be able to harvest yeast from that tank after that point, and I don't really want to lose any aromatics. I'd rather not increase biofine additions, because we are able to keep a nice head on the beer currently, and higher levels tend to screw that up. Higher calcium rates tend to give us a minerally flavor.

    Just wondering if anyone else has experienced this or has some other ideas I haven't considered yet. Thanks all.

  • #2
    The taller the tank, the longer the crash. Give it an extra day.

    Possibly check if your glycol jackets are not functioning properly and if you are getting any temp stratification.

    You also need to increase biofine usage - breweries I've worked at are usually in the 100ml/bbl range, with no head retention issues, and a 20 to 30 minute gentle re circulation if you have a VFD pump would be a good idea as well when using finings.

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    • #3
      Originally posted by theomuller View Post
      The taller the tank, the longer the crash. Give it an extra day.

      Possibly check if your glycol jackets are not functioning properly and if you are getting any temp stratification.

      You also need to increase biofine usage - breweries I've worked at are usually in the 100ml/bbl range, with no head retention issues, and a 20 to 30 minute gentle re circulation if you have a VFD pump would be a good idea as well when using finings.


      I appreciate your feedback. I've found that biofine usage doesn't seem to be the determining factor. Before I took over here they were using 3L of biofine for 7 bbls with similar results, which is an insane amount. I've experimented increasing from 200 mL to the 400-500 mL range with no results. I can stay crashed for 10 days and not see clear beer till I'm in the keg for a week. Also, it's inconsistent. Some beers clear up well within two days, others don't clear at all. Currently we dose the tank by firing the biofine in with a brink after crashing and yeast dump, then start carbonation to stir everything up. I should mention we have to carbonate in the fermentor, no 7 bbl brites

      I've considered recirculation, I don't mind the extra time it takes, but I'm weary of beating the beer up too much. I've experienced that at other breweries I've worked at where aroma will just be completely lost. Might have to go back and try that one tho.

      We are currently using WLP005, WLP540, Safale S-04, and Safbrew BE-256. It's the inconsistency with flocculation that really gets me. The process doesn't change, but the results vary. I've also broken all the tank down and did a deep clean, just to eliminate the possibility that there was a contamination somewhere giving us cloudiness, but its inconsistent between tanks too.

      I should mention grains don't seem to be a determining factor either. I've had beers with similar amounts of wheat in the grist go completely clear sometimes, and not at all in others.

      Anyway, I'm at a bit of a loss.

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      • #4
        You don't say where you are sampling from. Correct me if I am wrong, but you have problems with the beer ex the small tanks when you are racking off into keg, but not the big ones, and that is the problem. Or is it also apparent at the sample point, which is presumably above the cone, in the sidewall?

        So lets deal with finings first. I have worked with 20 metre + high fermenters, and they fine within 24 hours (providing the yeast strain reacts with finings - not all, but SO4 for one definitely does). So I doubt very much if that is the problem.

        If you are seeing the problem after racking into kegs, then it is almost certainly the shallower angle of the cone, which does not allow the yeast to slide down the cone easily. Even with a 60 degree cone, I have seen slugs of yeast slide down after all the yeast has supposedly been removed, and particularly as the beer level drops into the cone and uncovers any residual yeast / protein layer. I know of one very large brewery that has a similar problem and they are trying to resolve the issue by mirror polishing the cone (currently ongoing), but I have no idea how they are getting on, so cannot say if this works.

        Two possible other options I can see.

        One is to transfer the beer after fining to another of these tanks and let it resettle - though I don't think this will resolve it totally

        Second is to use cone side wall variable height draw off points, or alter the base of the vessel so it has an upstand in it, and draw your beer off through that, as well as a CIP scavenge / yeast removal point.
        dick

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        • #5
          Well, you could try prefining with alginex, which I believe is an Irish moss derivative for counterfining. It's used in tiny amounts pre biofine and has dropped beers crystal clear at my current gig when combined with spindasol, which is our primary fining agent. We use it for certain of our fruit beers.

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          • #6
            Zinc! Why has no one brought up a zinc deficiency? This should be one of the first places to look after mutated yeast for flocculation issues. Zinc plays a huge role in how yeast flocculate, low zinc on a highly flocculant strain can cause problems. If you are not using a yeast nutrient, you should start doing that. See what happens.
            Also, and this probably doesn't help the situation at all either, but 45 degree cones have a different convection pattern that could also be fighting the yeast settling. You might try and only cool the side jackets and not the cone during the first part of crashing to try and force more yeast down.

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            • #7
              Originally posted by jebzter View Post
              Zinc! Why has no one brought up a zinc deficiency? This should be one of the first places to look after mutated yeast for flocculation issues. Zinc plays a huge role in how yeast flocculate, low zinc on a highly flocculant strain can cause problems. If you are not using a yeast nutrient, you should start doing that. See what happens.
              Also, and this probably doesn't help the situation at all either, but 45 degree cones have a different convection pattern that could also be fighting the yeast settling. You might try and only cool the side jackets and not the cone during the first part of crashing to try and force more yeast down.
              Interesting, my understanding was that wort should provide a near perfect environment for fermentation. I haven't had my wort tested for zinc levels, so that may be a first step. I know you can throw spent yeast into the boil to act as a nutrient. I'm working in 8 bbl batches, would there be a minimum pitching rate to aim for?

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              • #8
                Originally posted by dick murton View Post
                You don't say where you are sampling from. Correct me if I am wrong, but you have problems with the beer ex the small tanks when you are racking off into keg, but not the big ones, and that is the problem. Or is it also apparent at the sample point, which is presumably above the cone, in the sidewall?

                So lets deal with finings first. I have worked with 20 metre + high fermenters, and they fine within 24 hours (providing the yeast strain reacts with finings - not all, but SO4 for one definitely does). So I doubt very much if that is the problem.

                If you are seeing the problem after racking into kegs, then it is almost certainly the shallower angle of the cone, which does not allow the yeast to slide down the cone easily. Even with a 60 degree cone, I have seen slugs of yeast slide down after all the yeast has supposedly been removed, and particularly as the beer level drops into the cone and uncovers any residual yeast / protein layer. I know of one very large brewery that has a similar problem and they are trying to resolve the issue by mirror polishing the cone (currently ongoing), but I have no idea how they are getting on, so cannot say if this works.

                Two possible other options I can see.

                One is to transfer the beer after fining to another of these tanks and let it resettle - though I don't think this will resolve it totally

                Second is to use cone side wall variable height draw off points, or alter the base of the vessel so it has an upstand in it, and draw your beer off through that, as well as a CIP scavenge / yeast removal point.
                We pull our samples above the cone in all fermenters, and we have a racking port that we keg from that sits near the top of the cone. Almost always the beer clears up in the keg, it's about 50/50 in the 7 bbl fermenters, doesn't depend on yeast strain from the notes that I've took. Time doesn't make a difference either. I've had a double IPA crashed for a week and a half that hasn't cleared up at all, with 400 mL of biofine fired in, which is double what I usually need. The inconsistency of results is what gets me, when processes don't change.

                Comment


                • #9
                  Originally posted by adw1984 View Post
                  I've had a double IPA crashed for a week and a half that hasn't cleared up at all, with 400 mL of biofine fired in, which is double what I usually need. The inconsistency of results is what gets me, when processes don't change.
                  Sounds like you need to do a full review of the biofine dosing with each beer style. Biofine doesn't work well if you don't get the dosing right. Each beer is different. Once your protocol is set, make sure you brew consistently. If the results start varying, it's time to evaluate the dosing again.

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                  • #10
                    Originally posted by mswebb View Post
                    Sounds like you need to do a full review of the biofine dosing with each beer style. Biofine doesn't work well if you don't get the dosing right. Each beer is different. Once your protocol is set, make sure you brew consistently. If the results start varying, it's time to evaluate the dosing again.
                    So what is your dosing if you dont mind
                    Mike Eme
                    Brewmaster

                    Comment


                    • #11
                      Originally posted by adw1984 View Post
                      Interesting, my understanding was that wort should provide a near perfect environment for fermentation. I haven't had my wort tested for zinc levels, so that may be a first step. I know you can throw spent yeast into the boil to act as a nutrient. I'm working in 8 bbl batches, would there be a minimum pitching rate to aim for?
                      Wort is frequently deficient in zinc. Even more so if using adjuncts, but I suspect that you do not use much of those. As others have said, you definitely need to dial in your biofine dose, you also need to get the beer to 33F or as close as you can get to it(flocculation performance goes up rapidly with lower temperatures), and you need to make sure that the yeast can actually flocculate. Zinc is important to yeast flocculation, low zinc can make a highly flocculant strain a medium or low flocculating strain. I would not just throw dead yeast in the boil, it can be done but if it comes from a low zinc environment, they will also have low zinc. Servomyces, the white lab equivalent as well are yeast products that are saturated with zinc. YeastX 82 is what we use, it comes from BSG, it works very well, have not had any issues with it. It also contains some other nutrients, which are important if you are repitching yeast and want to get some more generations out of it. If you're not an MBAA member, you should consider joining, they have many journal articles about yeast, flocculation, nutrients, and anything else brewing.

                      Comment


                      • #12
                        Originally posted by mswebb View Post
                        Sounds like you need to do a full review of the biofine dosing with each beer style. Biofine doesn't work well if you don't get the dosing right. Each beer is different. Once your protocol is set, make sure you brew consistently. If the results start varying, it's time to evaluate the dosing again.
                        So what is your dosing if you dont mind
                        Mike Eme
                        Brewmaster

                        Comment


                        • #13
                          Originally posted by beerguy1 View Post
                          So what is your dosing if you dont mind
                          Don't use it anymore as we didn't have the time/staff to manage proper protocols and got inconsistent results. Even if I did, my dosing would be irrelevant, merely a ballpark figure without fine tuning to your wort. You have to go through the proper testing with each of your beer styles over at least a couple of brews each to lock down what the standard dose for each beer is. As I indicated above, if you start getting inconsistent results, it's time to do the testing again or figure out what in your process (could be protein load in your grain so check everything) to see where the difference is coming in.

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