Ask The Brewmasters

We recently had plates sampled from one of our brite tanks show substantial growth on UBA and LMDA plates (showing substantial acid production by the CFUs).  We immediately scrapped plans to package this beer. Subsequently our Lab Manager re-plated and again saw rampant growth on LMDA both aerobically and anaerobically.  Isolated CFUs were stained and diastase test performed.  Under the microscope the bacteria appeared to be rod-shaped and gram-positive leading us to believe that it was Lactobacillus.  Additionally, we inoculated HLP media with samples from this brite tank and they returned with substantial colonies of comet-like CFUs…also indicating Lactobacillus.  We then sent samples to our yeast supplier to run PCR and they confirmed the presence of hop tolerant Lactobacillus.  We have plans to destroy this beer (despite evidence now showing that the infection is isolated to the sample valve…but more on that later).  So, I'd like to run through my plans to safely remediate this infection and get your feedback.  ALL other tanks in the cellar have come back clean and free of contamination, with repeated platings on LMDA and HLP. 

My plan is to use 1/2" tubing run to our drain to slowly drain the tank so as not to tax our wastewater.  Once drained we will acid wash, then fully de-gas, fully evacuate the tank of CO2, then run a caustic cycle.  All gaskets will be replaced.  Post CIP we will confirm cleaning with an ATP swab.  Once passed, the tank will then get filled with water which will be pushed out of the tank to fully purge the vessel and rid it of most of the oxygen.  The tank will then be sanitized under pressure using PAA to the appropriate strength.   

Does this course of action seem sufficient?  Overkill?  Just right?  Suggestions on a better course of action?  We have been fortunate to have never encountered this issue before and hopefully won't ever again.  

Getting back to the sample valve…it is a Perlick-style valve with rubber cup seal, rather than the old school swivel style zwickel.  A subsequent plating on LMDA and HLP of a sample taken from the bottom of the tank showed zero growth.  Absolutely clean.  Obviously this points to bacterial build up in the sample valve gasket AND/Or introduction of hop tolerant lactobacillus THROUGH the sample valve, most likely from an over-pressurized and contaminated Zahm.  So, the follow up question here is… is there anyone out there sanitizing their Zahm prior to use?  How are you doing so?  Other than a few gaskets on the interior of the Zahm, would their be any reason we couldn't or shouldn't pack the Zahm in iodine-based sanitizer or PAA?  Is there a "best practices" article regarding Zahm cleaning, maintenance, use, and sanitation?

We recently had plates sampled from one of our brite tanks show substantial growth on UBA and LMDA plates (showing substantial acid production by the CFUs).  We immediately scrapped plans to package this beer. Subsequently our Lab Manager re-plated and again saw rampant growth on LMDA both aerobically and anaerobically.  Isolated CFUs were stained and diastase test performed.  Under the microscope the bacteria appeared to be rod-shaped and gram-positive leading us to believe that it was Lactobacillus.  Additionally, we inoculated HLP media with samples from this brite tank and they returned with substantial colonies of comet-like CFUs…also indicating Lactobacillus.  We then sent samples to our yeast supplier to run PCR and they confirmed the presence of hop tolerant Lactobacillus.  We have plans to destroy this beer (despite evidence now showing that the infection is isolated to the sample valve…but more on that later).  So, I'd like to run through my plans to safely remediate this infection and get your feedback.  ALL other tanks in the cellar have come back clean and free of contamination, with repeated platings on LMDA and HLP. 

My plan is to use 1/2" tubing run to our drain to slowly drain the tank so as not to tax our wastewater.  Once drained we will acid wash, then fully de-gas, fully evacuate the tank of CO2, then run a caustic cycle.  All gaskets will be replaced.  Post CIP we will confirm cleaning with an ATP swab.  Once passed, the tank will then get filled with water which will be pushed out of the tank to fully purge the vessel and rid it of most of the oxygen.  The tank will then be sanitized under pressure using PAA to the appropriate strength.   

Does this course of action seem sufficient?  Overkill?  Just right?  Suggestions on a better course of action?  We have been fortunate to have never encountered this issue before and hopefully won't ever again.  

Getting back to the sample valve…it is a Perlick-style valve with rubber cup seal, rather than the old school swivel style zwickel.  A subsequent plating on LMDA and HLP of a sample taken from the bottom of the tank showed zero growth.  Absolutely clean.  Obviously this points to bacterial build up in the sample valve gasket AND/Or introduction of hop tolerant lactobacillus THROUGH the sample valve, most likely from an over-pressurized and contaminated Zahm.  So, the follow up question here is… is there anyone out there sanitizing their Zahm prior to use?  How are you doing so?  Other than a few gaskets on the interior of the Zahm, would their be any reason we couldn't or shouldn't pack the Zahm in iodine-based sanitizer or PAA?  Is there a "best practices" article regarding Zahm cleaning, maintenance, use, and sanitation?

We recently had plates sampled from one of our brite tanks show substantial growth on UBA and LMDA plates (showing substantial acid production by the CFUs).  We immediately scrapped plans to package this beer. Subsequently our Lab Manager re-plated and again saw rampant growth on LMDA both aerobically and anaerobically.  Isolated CFUs were stained and diastase test performed.  Under the microscope the bacteria appeared to be rod-shaped and gram-positive leading us to believe that it was Lactobacillus.  Additionally, we inoculated HLP media with samples from this brite tank and they returned with substantial colonies of comet-like CFUs…also indicating Lactobacillus.  We then sent samples to our yeast supplier to run PCR and they confirmed the presence of hop tolerant Lactobacillus.  We have plans to destroy this beer (despite evidence now showing that the infection is isolated to the sample valve…but more on that later).  So, I'd like to run through my plans to safely remediate this infection and get your feedback.  ALL other tanks in the cellar have come back clean and free of contamination, with repeated platings on LMDA and HLP. 

My plan is to use 1/2" tubing run to our drain to slowly drain the tank so as not to tax our wastewater.  Once drained we will acid wash, then fully de-gas, fully evacuate the tank of CO2, then run a caustic cycle.  All gaskets will be replaced.  Post CIP we will confirm cleaning with an ATP swab.  Once passed, the tank will then get filled with water which will be pushed out of the tank to fully purge the vessel and rid it of most of the oxygen.  The tank will then be sanitized under pressure using PAA to the appropriate strength.   

Does this course of action seem sufficient?  Overkill?  Just right?  Suggestions on a better course of action?  We have been fortunate to have never encountered this issue before and hopefully won't ever again.  

Getting back to the sample valve…it is a Perlick-style valve with rubber cup seal, rather than the old school swivel style zwickel.  A subsequent plating on LMDA and HLP of a sample taken from the bottom of the tank showed zero growth.  Absolutely clean.  Obviously this points to bacterial build up in the sample valve gasket AND/Or introduction of hop tolerant lactobacillus THROUGH the sample valve, most likely from an over-pressurized and contaminated Zahm.  So, the follow up question here is… is there anyone out there sanitizing their Zahm prior to use?  How are you doing so?  Other than a few gaskets on the interior of the Zahm, would their be any reason we couldn't or shouldn't pack the Zahm in iodine-based sanitizer or PAA?  Is there a "best practices" article regarding Zahm cleaning, maintenance, use, and sanitation?

We recently had plates sampled from one of our brite tanks show substantial growth on UBA and LMDA plates (showing substantial acid production by the CFUs).  We immediately scrapped plans to package this beer. Subsequently our Lab Manager re-plated and again saw rampant growth on LMDA both aerobically and anaerobically.  Isolated CFUs were stained and diastase test performed.  Under the microscope the bacteria appeared to be rod-shaped and gram-positive leading us to believe that it was Lactobacillus.  Additionally, we inoculated HLP media with samples from this brite tank and they returned with substantial colonies of comet-like CFUs…also indicating Lactobacillus.  We then sent samples to our yeast supplier to run PCR and they confirmed the presence of hop tolerant Lactobacillus.  We have plans to destroy this beer (despite evidence now showing that the infection is isolated to the sample valve…but more on that later).  So, I'd like to run through my plans to safely remediate this infection and get your feedback.  ALL other tanks in the cellar have come back clean and free of contamination, with repeated platings on LMDA and HLP. 

My plan is to use 1/2" tubing run to our drain to slowly drain the tank so as not to tax our wastewater.  Once drained we will acid wash, then fully de-gas, fully evacuate the tank of CO2, then run a caustic cycle.  All gaskets will be replaced.  Post CIP we will confirm cleaning with an ATP swab.  Once passed, the tank will then get filled with water which will be pushed out of the tank to fully purge the vessel and rid it of most of the oxygen.  The tank will then be sanitized under pressure using PAA to the appropriate strength.   

Does this course of action seem sufficient?  Overkill?  Just right?  Suggestions on a better course of action?  We have been fortunate to have never encountered this issue before and hopefully won't ever again.  

Getting back to the sample valve…it is a Perlick-style valve with rubber cup seal, rather than the old school swivel style zwickel.  A subsequent plating on LMDA and HLP of a sample taken from the bottom of the tank showed zero growth.  Absolutely clean.  Obviously this points to bacterial build up in the sample valve gasket AND/Or introduction of hop tolerant lactobacillus THROUGH the sample valve, most likely from an over-pressurized and contaminated Zahm.  So, the follow up question here is… is there anyone out there sanitizing their Zahm prior to use?  How are you doing so?  Other than a few gaskets on the interior of the Zahm, would their be any reason we couldn't or shouldn't pack the Zahm in iodine-based sanitizer or PAA?  Is there a "best practices" article regarding Zahm cleaning, maintenance, use, and sanitation?

We recently had plates sampled from one of our brite tanks show substantial growth on UBA and LMDA plates (showing substantial acid production by the CFUs).  We immediately scrapped plans to package this beer. Subsequently our Lab Manager re-plated and again saw rampant growth on LMDA both aerobically and anaerobically.  Isolated CFUs were stained and diastase test performed.  Under the microscope the bacteria appeared to be rod-shaped and gram-positive leading us to believe that it was Lactobacillus.  Additionally, we inoculated HLP media with samples from this brite tank and they returned with substantial colonies of comet-like CFUs…also indicating Lactobacillus.  We then sent samples to our yeast supplier to run PCR and they confirmed the presence of hop tolerant Lactobacillus.  We have plans to destroy this beer (despite evidence now showing that the infection is isolated to the sample valve…but more on that later).  So, I'd like to run through my plans to safely remediate this infection and get your feedback.  ALL other tanks in the cellar have come back clean and free of contamination, with repeated platings on LMDA and HLP. 

My plan is to use 1/2" tubing run to our drain to slowly drain the tank so as not to tax our wastewater.  Once drained we will acid wash, then fully de-gas, fully evacuate the tank of CO2, then run a caustic cycle.  All gaskets will be replaced.  Post CIP we will confirm cleaning with an ATP swab.  Once passed, the tank will then get filled with water which will be pushed out of the tank to fully purge the vessel and rid it of most of the oxygen.  The tank will then be sanitized under pressure using PAA to the appropriate strength.   

Does this course of action seem sufficient?  Overkill?  Just right?  Suggestions on a better course of action?  We have been fortunate to have never encountered this issue before and hopefully won't ever again.  

Getting back to the sample valve…it is a Perlick-style valve with rubber cup seal, rather than the old school swivel style zwickel.  A subsequent plating on LMDA and HLP of a sample taken from the bottom of the tank showed zero growth.  Absolutely clean.  Obviously this points to bacterial build up in the sample valve gasket AND/Or introduction of hop tolerant lactobacillus THROUGH the sample valve, most likely from an over-pressurized and contaminated Zahm.  So, the follow up question here is… is there anyone out there sanitizing their Zahm prior to use?  How are you doing so?  Other than a few gaskets on the interior of the Zahm, would their be any reason we couldn't or shouldn't pack the Zahm in iodine-based sanitizer or PAA?  Is there a "best practices" article regarding Zahm cleaning, maintenance, use, and sanitation?