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  • Infection

    Hello, Looking for some advice because I must be missing something. We have had to dump our last few batches due to infection. Seems to be acetobacter based on my research. First bad batch was a Siason, didn't notice until kegged.

    Since, we've eliminated o2 stone and sightglass from cold side plumbing. HX was broken down, cleaned plate by plate, reassembled loosely, soaked in caustic, then boiled in the BK along with TC fittings and new hoses for an hour. HX was reassembled and boiling wort is recirculated through cold side plumbing for 15 minutes prior to chill. Our last batch, we took 3 wort stability samples, one off the hot side, one post HX and one post FV.

    Hot side sample shows no activity after 4 days, post HX and post FV were clean til day 3 when two dots of white mold showed up on the sides at top of wort.

    I took whirlpool valve and sight glass off BK last night and found some crud, have everything soaking now in PBW. Maybe toward end of chill when temps go down, this could be a culprit? Another thought I had is that we have been bagging hops and tying to handle of BK so they dont float down and get scorched, when level goes down, bags are hanging there and draining......... Looking to see if anyone else has experienced this and if anyone has any ideas of what I could be missing, or if activity after 3 days in wort stability test is acceptable. I tasted the beer in FV last night and no off flavors....yet

  • #2
    Cold side infection. Break down your fermenters thoroughly (every part, fitting, PRV, sprayball arm) and inspect or replace your KO hose.

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    • #3
      Originally posted by theomuller View Post
      Cold side infection. Break down your fermenters thoroughly (every part, fitting, PRV, sprayball arm) and inspect or replace your KO hose.
      +1

      And review your yeast handling SOPs.

      Comment


      • #4
        Thanks for the replies, FV's are plastic, but all fittings have been removed and boiled. The wort stability sample that was taken before the fv showed activity as well after 3 days. KO hoses are new and were boiled.

        We are not re-pitching yeast. This last batch, we pitched safeale 05 dry yeast

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        • #5
          Welp if it is acetobacter, that's a pretty easy microbe to track down. Its a strict aerobe. We know it is producing acetic acid only where there is oxygen.

          The question is now, how committed are you to tracking this down and how quickly would you like to do so? You are going to have to learn or find someone with some (very) basic lab skills.

          Do you have a pH meter? This could assist you in finding the source, as you could look for an unexpected pH drop.

          Basic lab work:

          Look at the BSI lab handbook. We're going to be spread plating.

          Order pre-made LMDA plates from White Labs or BSI or some other yeast/lab company.

          Order some sterile pipettes (1ml). Cynmar is a good place for small quantities. Maybe some sterile transfer tubes(50mL is fine) as well.

          Take a sample as aseptically as possible. Pipet ~0.1mL from the transfer tube on the plate, then spread with a sterile spreader(in a pinch a alcohol dipped paper clip works).

          Place plates upside down in a warm room and wait a few days. Look at the BSI key for LMDA and identify.

          Where you take your samples is the most important part. You want to find the point in the process where the previous sample was clean and the next is not, that tells you where the contamination is being introduced.
          Last edited by AT-JeffT; 08-02-2017, 02:09 PM.

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          • #6
            Thanks Jeff, We need to track this down asap. I do have a ph meter, I have only really used for mash ph up to now.

            This is very helpful, I will order these supplies and take as many samples as I can to try to isolate.

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            • #7
              Originally posted by jrtredo View Post
              Thanks Jeff, We need to track this down asap. I do have a ph meter, I have only really used for mash ph up to now.

              This is very helpful, I will order these supplies and take as many samples as I can to try to isolate.
              Sure thing. Using the pH meter will be tough without a baseline.

              If the contamination is severe, which it sounds like it. It should be easy to find via plating.

              Also, work near a flame. This creates a sterile field to work in. Yeast, by White and Zainasheff is great for outlining basic aseptic lab techniques.

              Lastly, Teri Fahrendorf's Lab manual is a great resource.

              Good luck. I'll try and answer any other questions you have as they pop up.

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              • #8
                Thanks, ordered supplies, but will take a bit to get here. Going to run a small test batch with malt extract tonight. Will take samples all along the cold side during the chill and put in sanitized ball jars and observe for the next few days and note activity. Will be a bit tricky to get the samples (unclamping tri clamps, hoses etc, ) but will do the best we can, and report results

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                • #9
                  We did a test batch and I collected the wort stability samples and place in sanitzed jars. Samples from BK valve and pre HX were both clean and stable up until over a week later. The sample from the out valve of HX stayed had slight pressure in it within 24 hours, post thermorwell sample has pressure in it as well after 24 hours, pre FV sample has noticeable activity in it within 24 hours, post FV sample had noticeable activity within 48. All samples on the cold side eventually showed noticeable activity within 5 days.

                  I ordered a new HX and expect it to be delivered this Thursday. I have borrowed an ozonator on the off chance the bacteria is airborne. I received the LMDA plates from BSI and will conduct a test batch with malt extract when the HX arrives and take sample again.

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                  • #10
                    Damn - you don't expect that further cleaning/sanitizing/boiling could clean the HX to prevent future infections? Brutal.
                    Ryan
                    Viridian Brewing Company
                    [Brewery-In-Planning]

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                    • #11
                      Originally posted by jrtredo View Post
                      We did a test batch and I collected the wort stability samples and place in sanitzed jars. Samples from BK valve and pre HX were both clean and stable up until over a week later. The sample from the out valve of HX stayed had slight pressure in it within 24 hours, post thermorwell sample has pressure in it as well after 24 hours, pre FV sample has noticeable activity in it within 24 hours, post FV sample had noticeable activity within 48. All samples on the cold side eventually showed noticeable activity within 5 days.

                      I ordered a new HX and expect it to be delivered this Thursday. I have borrowed an ozonator on the off chance the bacteria is airborne. I received the LMDA plates from BSI and will conduct a test batch with malt extract when the HX arrives and take sample again.
                      A new HX seems extreme. Is your old one brazed? We have 3 HX's in use from the 90's all giving us no micro issues. I'd look into your hose cleaning and sanitation procedures. We're finding that +180F water is far superior to chemical sanitizing when it comes to hoses.

                      I would discontinue the process of boiling stuff, and start boiling water in your kettle and CIP/SIP equipment like the HX and hoses in place. Be safe about it though.

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                      • #12
                        I second using 180F water to pasteurize transfer lines, HX and anything else. Flash pasteurization... nothing survives that. My standard process for my pump/HX loop is: PBW, sanitizer and then pasteurize for 5minutes with 185F water.
                        Ryan
                        Viridian Brewing Company
                        [Brewery-In-Planning]

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                        • #13
                          I know...we are running out of ideas though and have had to dump 7 batches now. Our current chiller is from Sabco, Plate-Pro, it is actually a rebadged thermaline t-2. We have put it through the paces and figure that since there was activity in the sample we took right off the cold side valve, it must still be causing the problem.

                          We have been using hot water (175) for 20 minutes through spray ball to sanitize our plastic fermentors. We always recirculate the boiling wort through the HX and all cold side hoses, fittings for at least 15 minutes prior to chill.

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                          • #14
                            Originally posted by jrtredo View Post
                            I know...we are running out of ideas though and have had to dump 7 batches now. Our current chiller is from Sabco, Plate-Pro, it is actually a rebadged thermaline t-2. We have put it through the paces and figure that since there was activity in the sample we took right off the cold side valve, it must still be causing the problem.

                            We have been using hot water (175) for 20 minutes through spray ball to sanitize our plastic fermentors. We always recirculate the boiling wort through the HX and all cold side hoses, fittings for at least 15 minutes prior to chill.
                            I've not heard of using a spray ball to pasteurize a tank. Typically you would only use chemical sanitizers through a spray ball. You would fill a tank to the brim when using water to pasteurize it. Have you taken a temperature of at the outlet of the fv at the end of the cycle? I'm guessing that water is cooling down too much to be an effective sanitizer.

                            Hmm, recirculating the wort is non-traditional but I can't see why it wouldn't work. I would be more comfortable with a water recirc beforehand and skipping the wort recirc though.

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                            • #15
                              Hello,

                              You may want to try an ATP tester to verify your sanitation procedures. Charm, 3M, Hygiena all make them. It wont identify the infection or if it is viable, but will let you know if your equipment is clean. Just a thought.

                              http://www.hygiena.com/beer-and-wine-processors.html

                              What makes you believe it is acetobacter?

                              How well separated is grain handling/crushing from fermentation and production areas?

                              Spoilage organisms can hide well in the scratches on plastic equipment.

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