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  • Dissolved oxygen meter

    Wondering if someone can give me a quick primer on how to use a dissolved oxygen meter. I’m head brewer at a Brewpub and my business partner purchased a DO meter because our score sheets from GABF said our beers were oxidized. So my business partner, who isn’t even a novice home brewer has been attempting to cure our oxidation issues.
    So what I need to know is what are desired numbers for DO in finished beer. He was told 15 ppm is what you want, then beer can be transferred to brite tanks. I feel like our oxidation issues are from a combination of things like our grain being stored in a machine shed that is not temp controlled. Also, in the summer I have a hard time cooling beer with our chill plates due to warm ground water temps.
    So if anyone could enlighten me on some things to do to minimize oxidation it would be greatly appreciated. We brew on a 2.5bbl Psycho Brew system. We brew double batches into 5bbl fermenters. I use Fermentis dry yeast and oxygenate our wort with a GW Kent in line oxygen stone.
    My business partner has also, to my dismay been purging yeast out of the bottom of our fermenters. I brewed a robust Porter with an OG of 16 Plato. He started dumping yeast after a week with a gravity of 6 Plato. He then got a DO reading of 8 and transferred it to a brite tank. The beer tastes like shit!
    I typically wait 10 to 12 days and check a gravity reading and if it is 75% attenuation I crash cool the beer to 50 degrees gradually and then transfer to a brite tank. From talking with brewers with similar brew houses they say it takes about two weeks for complete fermentation. My business partner seems to be concerned with auto lysis with the yeast but I have never experienced this flavor in our beers. Are auto lysis and oxidized issues related?
    Please help!


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  • #2
    First off, I've never used a DO meter before, but I have a few thoughts. Sorry I didn't answer your question, hope this gets you going in the right direction though.

    1) How are you packaging? How did you fill containers to send to GABF? If your beer doesn't normally taste oxidized, you can have picked up oxygen when you were packaging.

    2) I think you want to look at ppb, not ppm, for oxygen. From my understanding, meters that can read ppb are almost the same price as the brew system you guys have.

    3) Was the blowoff tube still active on the porter? Your protocol for taking gravities seems odd, you should probably be checking it more often than that. 75% seems like a so-so rule of thumb, but different yeasts (even if it's all fermentis) and mash temps or adjuncts can change the attenuation a lot.

    4) Is the brite tank purges with co2 before you transfer the beer into it? Are you pushing the beer with co2 or using a pump?

    5) Good luck, working with owners who think they know more than they do can be very frustrating.

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    • #3


      Refer to this thread for a DO meter


      As for fermentation, if its a healthy ferment it should be finished “fermenting” in 4-5 days, then 1-2 extra days for D rest, its pretty common for brewers to drop yeast after a week for dry hopping or other reasons. The yeast at the bottom isnt doing a whole lot anyways. At the same time, autolysis shouldnt be a concern that early either unless the beer is high gravity like >10%

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      • #4
        Ok, re-reading your post I need to point one more thing out.

        You said "He was told 15 ppm is what you want, then beer can be transferred to brite tanks." This statement doesn't make sense. Oxygen pickup during fermentation isn't what you need to be worried about. Oxygen is picked up every time you move the beer.

        Comment


        • #5
          Originally posted by BrewerJake View Post
          First off, I've never used a DO meter before, but I have a few thoughts. Sorry I didn't answer your question, hope this gets you going in the right direction though.

          1) How are you packaging? How did you fill containers to send to GABF? If your beer doesn't normally taste oxidized, you can have picked up oxygen when you were packaging.

          2) I think you want to look at ppb, not ppm, for oxygen. From my understanding, meters that can read ppb are almost the same price as the brew system you guys have.

          3) Was the blowoff tube still active on the porter? Your protocol for taking gravities seems odd, you should probably be checking it more often than that. 75% seems like a so-so rule of thumb, but different yeasts (even if it's all fermentis) and mash temps or adjuncts can change the attenuation a lot.

          4) Is the brite tank purges with co2 before you transfer the beer into it? Are you pushing the beer with co2 or using a pump?

          5) Good luck, working with owners who think they know more than they do can be very frustrating.
          I packaged our beers with a Blichmann beers gun. Purged bottles with CO2 then filled and used O2 absorbing caps.
          And yes the meter reads in ppb, I believe. Unfortunately I live 85 miles from this Brewpub I brew. I still have my day job as an ER nurse. So I rely on my stoned brewers assistant for most readings. I usually get more than 75% attenuation. I use mainly US05 and S04 yeast. Typically mash in the 152-154 range.

          We do purge brite tanks before transfers with CO2. We use pumps. Never thought about using CO2.

          Thanks for your thoughts. I read thousands of blogs about starting a Brewpub and it was people bitching about business partners. I thought mine was great at first talking all the time about “our” brewpub. Then a week before opening he turned into a total control freak micromanaging everything but for the most part staying away from brewing. Luckily I put none of my own money in this venture and can get out whenever I want. It just isn’t my dream and the whole operation is pretty mediocre and a total disappointment.


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          • #6
            Originally posted by BrewerJake View Post
            Ok, re-reading your post I need to point one more thing out.

            You said "He was told 15 ppm is what you want, then beer can be transferred to brite tanks." This statement doesn't make sense. Oxygen pickup during fermentation isn't what you need to be worried about. Oxygen is picked up every time you move the beer.
            He apparently got these numbers from a brewmaster at Blue Moon while he was at GABF. The research I’ve done says 0.015 ppm. But not sure what that is referring to. I think this piece of equipment is over our heads!


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            • #7
              Originally posted by samwhois View Post
              He apparently got these numbers from a brewmaster at Blue Moon while he was at GABF. The research I’ve done says 0.015 ppm. But not sure what that is referring to. I think this piece of equipment is over our heads!


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              Sorry, 0.015 ppb


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              • #8
                Originally posted by Junkyard View Post
                http://discussions.probrewer.com/sho...milton+beverly

                Refer to this thread for a DO meter


                As for fermentation, if its a healthy ferment it should be finished “fermenting” in 4-5 days, then 1-2 extra days for D rest, its pretty common for brewers to drop yeast after a week for dry hopping or other reasons. The yeast at the bottom isnt doing a whole lot anyways. At the same time, autolysis shouldnt be a concern that early either unless the beer is high gravity like >10%
                Thank you! I’m celebrating Thanksgiving today because I had to work yesterday and will dive into this as soon as I can.


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                • #9
                  Originally posted by samwhois View Post
                  Sorry, 0.015 ppb
                  No, I think you mean 0.015 ppm which would be equivalent to 15 ppb.

                  That is a pretty high standard (low number) for beer in package. I would suggest that a more average number would be between 25-55 ppb in canned or bottled product. 15ppb would be a great target for your BBT prior to packaging to get to a TPO (total packaged oxygen) content of 25-55ppb. The statement "He was told 15 ppm is what you want, then beer can be transferred to brite tanks" does make sense. Just because you have active fermentation does not mean you will have 0 ppb in the fermenter. Transferring with a pump is fine, provided you are using a pump with a good seal, and tighten your TC's appropriately, but at your size transferring with CO2 is likely easier, and reduces the risk of O2 pickup.

                  The yeast is a different situation. Autolysis will give you off flavors, but it will usually take longer than a week for it to begin to break down lipids. You can usually see and smell this in the yeast when you dump it as well. Seeing gritty yeast (not to be confused with cold break) at the bottom of the tank is a good sign some autolysis has taken place. If you remove it quickly, it should not have much time to impart flavor changes. Make sure you "crop" your yeast with re-pitches.

                  The yeast will consume oxygen while it is in the beer, so removing the yeast early would not necessarily benefit your concerns about O2. If your levels are above the 15 ppb mark in the fermenter, you may benefit from leaving the yeast in suspension a little longer. Allowing your yeast to sit for a few days after crashing but before harvesting will also allow the yeast to build up glycogen reserves (store energy) which will help it store longer and ferment stronger in subsequent batches.

                  As far as the equipment being over your head, it won't be for long. Use it as much as possible on every part of the process. It's really not complicated and you just need to know what the data means. If you give us the type of DO meter you purchased, that would help with some pointers. You should be very thankful for this equipment as it has a lot to do with the stability of your beer. Learn it before you move on somewhere else, that way when you don't have it, you can understand the principles.

                  To your other point, don't expect things to get better from a business partner perspective. Define your roles early and hold firm. "I make the beer, you do the books!" Don't allow the other person to have authority in the brew house without your approval. "You need to ask my approval before dumping yeast, crashing, ect". I have quit one a while back because the owner crashed my tank before it was ready. "But we need the beer Monday!" Well beer needed another 2 days and would have been fine. Instead we had tons of diacetyl in cans that didn't show up for a week. Luckily by then I had already moved on. It was the second time they had taken liberty without approval. Also decided to carb a tank for me and saturated it to 22psi. Roughly 3.8 Volumes. I told him we cant can it like that, and insisted we at least try because again we needed the beer. Wasted a good 3 BBL before he admitted it would need to wait another day. Very infuriating. You do your job and I'll do mine is very important. You need to work with people who respect you and your position. You can't force good production, you have to enable it.

                  Comment


                  • #10
                    Originally posted by UnFermentable View Post
                    No, I think you mean 0.015 ppm which would be equivalent to 15 ppb.

                    That is a pretty high standard (low number) for beer in package. I would suggest that a more average number would be between 25-55 ppb in canned or bottled product. 15ppb would be a great target for your BBT prior to packaging to get to a TPO (total packaged oxygen) content of 25-55ppb. The statement "He was told 15 ppm is what you want, then beer can be transferred to brite tanks" does make sense. Just because you have active fermentation does not mean you will have 0 ppb in the fermenter. Transferring with a pump is fine, provided you are using a pump with a good seal, and tighten your TC's appropriately, but at your size transferring with CO2 is likely easier, and reduces the risk of O2 pickup.

                    The yeast is a different situation. Autolysis will give you off flavors, but it will usually take longer than a week for it to begin to break down lipids. You can usually see and smell this in the yeast when you dump it as well. Seeing gritty yeast (not to be confused with cold break) at the bottom of the tank is a good sign some autolysis has taken place. If you remove it quickly, it should not have much time to impart flavor changes. Make sure you "crop" your yeast with re-pitches.

                    The yeast will consume oxygen while it is in the beer, so removing the yeast early would not necessarily benefit your concerns about O2. If your levels are above the 15 ppb mark in the fermenter, you may benefit from leaving the yeast in suspension a little longer. Allowing your yeast to sit for a few days after crashing but before harvesting will also allow the yeast to build up glycogen reserves (store energy) which will help it store longer and ferment stronger in subsequent batches.

                    As far as the equipment being over your head, it won't be for long. Use it as much as possible on every part of the process. It's really not complicated and you just need to know what the data means. If you give us the type of DO meter you purchased, that would help with some pointers. You should be very thankful for this equipment as it has a lot to do with the stability of your beer. Learn it before you move on somewhere else, that way when you don't have it, you can understand the principles.

                    To your other point, don't expect things to get better from a business partner perspective. Define your roles early and hold firm. "I make the beer, you do the books!" Don't allow the other person to have authority in the brew house without your approval. "You need to ask my approval before dumping yeast, crashing, ect". I have quit one a while back because the owner crashed my tank before it was ready. "But we need the beer Monday!" Well beer needed another 2 days and would have been fine. Instead we had tons of diacetyl in cans that didn't show up for a week. Luckily by then I had already moved on. It was the second time they had taken liberty without approval. Also decided to carb a tank for me and saturated it to 22psi. Roughly 3.8 Volumes. I told him we cant can it like that, and insisted we at least try because again we needed the beer. Wasted a good 3 BBL before he admitted it would need to wait another day. Very infuriating. You do your job and I'll do mine is very important. You need to work with people who respect you and your position. You can't force good production, you have to enable it.
                    Great stuff! Thank you. I will get the type of DO meter we have. Unfortunately, I live 85 miles from this Brewpub and feel like it is a lost cause but I want to learn everything I can for future use.

                    Thanks again


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                    • #11
                      I think in the future I will try and push our beer with CO2. We have March pumps but I really question how well the seals are.
                      I’m hoping to start a Nano brewery in my home town but not sure if it is worth it. I live in downstate Illinois in a economically depressed town of 30,000 people. I’m not wanting to do it for the money but more for the art of it. Our brewpub is in a economically depressed town in Southeastern Iowa, with a population of 10,000. I would love to do more with the brewpub but not willing to move to the shitty little town it is in and 85 miles is a hell of a commute. We don’t package any of our beer, just keg and sell growlers. I’m somewhat stuck in Illinois and need a business partner that shares my vision. I’m not asking for much. A decent logo and open communication. This guy I work with now is stuck in 1985 and it is his way or no way. He’s a previous Pizza Hut franchise owner and we have a family owned restaurant that we pay a dollar a month for rent. It was a Sirloin Stockade “hog trough” as I like to call them in a previous life. The municipal water in this town is great and has been voted best tasting water in Iowa for seven years in a row. So I have that going for me! Our beers have been good but I think my biggest issue is chilling our wort after boil. We recently bought another chill plate but it is difficult to get the wort under 78 degrees in the summer when ground water temps are warm. I would suspect this might be another major oxidation place in my process. I haven’t been doing much yeast cropping because I don’t trust my assistant brewer. I think he’s great but maybe not the most detail oriented guy and he has a hearing problem on top of it.
                      My business partner always told me I could get out whenever I want and I have a weird feeling he wants me out sometimes. I was willing to spend more time at the brewpub until he started being a total control freak about everything and not telling me anything. Like I said it has been a big disappointment. I had a friend who’s a graphic designer create a logo for us that I thought looked awesome. A week before we opened he came up with this shitty logo that looks like a bad print job. I was also developing beer names and he would never give any approval or feedback and then says he wants to call them “V’s beach party brews”. I just gave up after that.
                      Anyway, thanks for all the great information and brewer therapy. I’ll get back with you all on the DO meter. I want to say it is a Hanna, but not 100% sure.


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                      • #12
                        I think you have more than one problem.

                        Based on what you've commented, the biggest issue you have is fermentation. Second biggest issue is probably tank management.

                        My guess is that you are not pitching sufficient yeast, probably fermenting at the wrong temperature (or your temperature variations are too great during the ferment).

                        If you're using dried yeast use it according to the package directions, and add more yeast if your OG is higher than the spec. Also, you should always hydrate dried yeast with sterile water prior to pitching. Your active primary fermentation should be complete in 5-6 days for a 13°P beer to ferment down to 2.5°P.

                        There is usually no need to dump yeast out mid-ferment, although sometimes there is a lot of junk in the bottom of the fermenter that doesn't do any good - things like sluggish yeast and cold-break material.

                        Also, you should be pushing your beer through with CO2. Your brite tank should be pre-purged with CO2 prior to filling, and it's also a good practice to "scrub" during carbonation. That is, carbonate to about 3-4 psi head space pressure and then let it out to zero slowly, then resume your carb cycle until completion.
                        Oxidation is the bane of most small brewers. The only way to combat that is with proper CO2 purging and learning where in your processes you introduce oxygen into finished beer. Usually that's during transfer.

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                        • #13
                          Thanks for the great information.


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