Ask The Brewmasters

Hello Fellow Brewers,

I have watched this tread with interest and agree with the caution expressed by Alex and Jeff.

We are in a dangerous time as brewers experiment with none traditional beverages. Mike Barney, retired expert microbiologist from Miller, has long warned us about the dangers of non alcoholic beers. Now the presence of beverages with high loads of fermentable extract are truly "bombs". We need to be thinking about "cells of beer spoilers per liter" not "per milliliter".

We all wish for a simple answer to the question, "How many PU's do I need?" but an easy answer doesn't exist as is evidenced by the frustrating "it depends".

I'm sorry to report that you need to do your own research. Define the quality of your beverages and offending microbes. Then work with an expert or a qualified supplier to design a system that you are comfortable with.

As I've said before, Dr. Werner Back at Weihenstephan has written some nice papers on this subject. Worth seeking out as a first step.

What types of microbes are your after? For example, spore formers are notoriously difficult to kill and might even be encouraged by heat treatment. Luckily, spore formers are not normally problematic in standard beers but may be important in none typical beverages. In some cases, with spore formers, a second pasteurization might be required or one pass with extremely high dose of PU's.

It also depends on the "inner stability" of your beer - % ABV, BU's, pH, Residual Extract, DO etc etc

Then one needs to consider turbidity. The presence of particles/pulp (as might be found in a fruit beer) can protect offending microbes from destruction.

If discussing Flash Pasteurization, one must take care to insure carbonation remains saturated. Gas breakout will offer protection against destruction from heat. The critical point for this is "Temperature versus Pressure" at the SUCTION side of the Booster Pump between Regeneration Sections.

Even the simple question, "How much back pressure do I need?" elicits a "it depends" response. The turbulence due to heat exchanger plate design is different between suppliers so that the required back pressure varies. And then you have to decide on a reasonable "safety factor". Then you have to consider fluctuations in system pressure as you go on stream or switch back and forth between recycle and forward flow.

It is estimated that 50% of contaminations occur in the Filling Hall. So Flash pasteurization will not protect you against re-condemnation from a dirty filler or crowner.

It is critical to remember that Pasteurization is NOT equivalent to sterilization. It is a "game of numbers". That is, pasteurization results only in a "log reduction" of micro load. Therefore it is best to not rely on pasteurization to destroy ALL offending microbes but rather to start pasteurization with a low microbiological load to improve the odds. I recommend to not rely on it to correct a beer with a high microbiological load.

I have heard stories of brewers that plate beer fresh off pasteurization and find "None Detected". But, follow up plating after a few weeks, shows regrowth from microbes that were "damaged" but not destroyed by this heat treatment.

Then, once you have a system in place, you need to take care to maintain it.

I know of many "horror stories" around failed pasteurization. Tunnel Pasteurizers with plugged spray nozzles. Flash Pasteurizers that were not properly designed or CIP'ed so that they become a source of contamination!

Like all aspects of brewing, one could spend a lifetime properly defining best practices. Sorry for the bad news.

Good Luck,

Daniel Carey

New Glarus Brewing Company

Hello Fellow Brewers,

I have watched this tread with interest and agree with the caution expressed by Alex and Jeff.

We are in a dangerous time as brewers experiment with none traditional beverages. Mike Barney, retired expert microbiologist from Miller, has long warned us about the dangers of non alcoholic beers. Now the presence of beverages with high loads of fermentable extract are truly "bombs". We need to be thinking about "cells of beer spoilers per liter" not "per milliliter".

We all wish for a simple answer to the question, "How many PU's do I need?" but an easy answer doesn't exist as is evidenced by the frustrating "it depends".

I'm sorry to report that you need to do your own research. Define the quality of your beverages and offending microbes. Then work with an expert or a qualified supplier to design a system that you are comfortable with.

As I've said before, Dr. Werner Back at Weihenstephan has written some nice papers on this subject. Worth seeking out as a first step.

What types of microbes are your after? For example, spore formers are notoriously difficult to kill and might even be encouraged by heat treatment. Luckily, spore formers are not normally problematic in standard beers but may be important in none typical beverages. In some cases, with spore formers, a second pasteurization might be required or one pass with extremely high dose of PU's.

It also depends on the "inner stability" of your beer - % ABV, BU's, pH, Residual Extract, DO etc etc

Then one needs to consider turbidity. The presence of particles/pulp (as might be found in a fruit beer) can protect offending microbes from destruction.

If discussing Flash Pasteurization, one must take care to insure carbonation remains saturated. Gas breakout will offer protection against destruction from heat. The critical point for this is "Temperature versus Pressure" at the SUCTION side of the Booster Pump between Regeneration Sections.

Even the simple question, "How much back pressure do I need?" elicits a "it depends" response. The turbulence due to heat exchanger plate design is different between suppliers so that the required back pressure varies. And then you have to decide on a reasonable "safety factor". Then you have to consider fluctuations in system pressure as you go on stream or switch back and forth between recycle and forward flow.

It is estimated that 50% of contaminations occur in the Filling Hall. So Flash pasteurization will not protect you against re-condemnation from a dirty filler or crowner.

It is critical to remember that Pasteurization is NOT equivalent to sterilization. It is a "game of numbers". That is, pasteurization results only in a "log reduction" of micro load. Therefore it is best to not rely on pasteurization to destroy ALL offending microbes but rather to start pasteurization with a low microbiological load to improve the odds. I recommend to not rely on it to correct a beer with a high microbiological load.

I have heard stories of brewers that plate beer fresh off pasteurization and find "None Detected". But, follow up plating after a few weeks, shows regrowth from microbes that were "damaged" but not destroyed by this heat treatment.

Then, once you have a system in place, you need to take care to maintain it.

I know of many "horror stories" around failed pasteurization. Tunnel Pasteurizers with plugged spray nozzles. Flash Pasteurizers that were not properly designed or CIP'ed so that they become a source of contamination!

Like all aspects of brewing, one could spend a lifetime properly defining best practices. Sorry for the bad news.

Good Luck,

Daniel Carey

New Glarus Brewing Company

Hello Fellow Brewers,

I have watched this tread with interest and agree with the caution expressed by Alex and Jeff.

We are in a dangerous time as brewers experiment with none traditional beverages. Mike Barney, retired expert microbiologist from Miller, has long warned us about the dangers of non alcoholic beers. Now the presence of beverages with high loads of fermentable extract are truly "bombs". We need to be thinking about "cells of beer spoilers per liter" not "per milliliter".

We all wish for a simple answer to the question, "How many PU's do I need?" but an easy answer doesn't exist as is evidenced by the frustrating "it depends".

I'm sorry to report that you need to do your own research. Define the quality of your beverages and offending microbes. Then work with an expert or a qualified supplier to design a system that you are comfortable with.

As I've said before, Dr. Werner Back at Weihenstephan has written some nice papers on this subject. Worth seeking out as a first step.

What types of microbes are your after? For example, spore formers are notoriously difficult to kill and might even be encouraged by heat treatment. Luckily, spore formers are not normally problematic in standard beers but may be important in none typical beverages. In some cases, with spore formers, a second pasteurization might be required or one pass with extremely high dose of PU's.

It also depends on the "inner stability" of your beer - % ABV, BU's, pH, Residual Extract, DO etc etc

Then one needs to consider turbidity. The presence of particles/pulp (as might be found in a fruit beer) can protect offending microbes from destruction.

If discussing Flash Pasteurization, one must take care to insure carbonation remains saturated. Gas breakout will offer protection against destruction from heat. The critical point for this is "Temperature versus Pressure" at the SUCTION side of the Booster Pump between Regeneration Sections.

Even the simple question, "How much back pressure do I need?" elicits a "it depends" response. The turbulence due to heat exchanger plate design is different between suppliers so that the required back pressure varies. And then you have to decide on a reasonable "safety factor". Then you have to consider fluctuations in system pressure as you go on stream or switch back and forth between recycle and forward flow.

It is estimated that 50% of contaminations occur in the Filling Hall. So Flash pasteurization will not protect you against re-condemnation from a dirty filler or crowner.

It is critical to remember that Pasteurization is NOT equivalent to sterilization. It is a "game of numbers". That is, pasteurization results only in a "log reduction" of micro load. Therefore it is best to not rely on pasteurization to destroy ALL offending microbes but rather to start pasteurization with a low microbiological load to improve the odds. I recommend to not rely on it to correct a beer with a high microbiological load.

I have heard stories of brewers that plate beer fresh off pasteurization and find "None Detected". But, follow up plating after a few weeks, shows regrowth from microbes that were "damaged" but not destroyed by this heat treatment.

Then, once you have a system in place, you need to take care to maintain it.

I know of many "horror stories" around failed pasteurization. Tunnel Pasteurizers with plugged spray nozzles. Flash Pasteurizers that were not properly designed or CIP'ed so that they become a source of contamination!

Like all aspects of brewing, one could spend a lifetime properly defining best practices. Sorry for the bad news.

Good Luck,

Daniel Carey

New Glarus Brewing Company

Hello Fellow Brewers,

I have watched this tread with interest and agree with the caution expressed by Alex and Jeff.

We are in a dangerous time as brewers experiment with none traditional beverages. Mike Barney, retired expert microbiologist from Miller, has long warned us about the dangers of non alcoholic beers. Now the presence of beverages with high loads of fermentable extract are truly "bombs". We need to be thinking about "cells of beer spoilers per liter" not "per milliliter".

We all wish for a simple answer to the question, "How many PU's do I need?" but an easy answer doesn't exist as is evidenced by the frustrating "it depends".

I'm sorry to report that you need to do your own research. Define the quality of your beverages and offending microbes. Then work with an expert or a qualified supplier to design a system that you are comfortable with.

As I've said before, Dr. Werner Back at Weihenstephan has written some nice papers on this subject. Worth seeking out as a first step.

What types of microbes are your after? For example, spore formers are notoriously difficult to kill and might even be encouraged by heat treatment. Luckily, spore formers are not normally problematic in standard beers but may be important in none typical beverages. In some cases, with spore formers, a second pasteurization might be required or one pass with extremely high dose of PU's.

It also depends on the "inner stability" of your beer - % ABV, BU's, pH, Residual Extract, DO etc etc

Then one needs to consider turbidity. The presence of particles/pulp (as might be found in a fruit beer) can protect offending microbes from destruction.

If discussing Flash Pasteurization, one must take care to insure carbonation remains saturated. Gas breakout will offer protection against destruction from heat. The critical point for this is "Temperature versus Pressure" at the SUCTION side of the Booster Pump between Regeneration Sections.

Even the simple question, "How much back pressure do I need?" elicits a "it depends" response. The turbulence due to heat exchanger plate design is different between suppliers so that the required back pressure varies. And then you have to decide on a reasonable "safety factor". Then you have to consider fluctuations in system pressure as you go on stream or switch back and forth between recycle and forward flow.

It is estimated that 50% of contaminations occur in the Filling Hall. So Flash pasteurization will not protect you against re-condemnation from a dirty filler or crowner.

It is critical to remember that Pasteurization is NOT equivalent to sterilization. It is a "game of numbers". That is, pasteurization results only in a "log reduction" of micro load. Therefore it is best to not rely on pasteurization to destroy ALL offending microbes but rather to start pasteurization with a low microbiological load to improve the odds. I recommend to not rely on it to correct a beer with a high microbiological load.

I have heard stories of brewers that plate beer fresh off pasteurization and find "None Detected". But, follow up plating after a few weeks, shows regrowth from microbes that were "damaged" but not destroyed by this heat treatment.

Then, once you have a system in place, you need to take care to maintain it.

I know of many "horror stories" around failed pasteurization. Tunnel Pasteurizers with plugged spray nozzles. Flash Pasteurizers that were not properly designed or CIP'ed so that they become a source of contamination!

Like all aspects of brewing, one could spend a lifetime properly defining best practices. Sorry for the bad news.

Good Luck,

Daniel Carey

New Glarus Brewing Company

Hello Fellow Brewers,

I have watched this tread with interest and agree with the caution expressed by Alex and Jeff.

We are in a dangerous time as brewers experiment with none traditional beverages. Mike Barney, retired expert microbiologist from Miller, has long warned us about the dangers of non alcoholic beers. Now the presence of beverages with high loads of fermentable extract are truly "bombs". We need to be thinking about "cells of beer spoilers per liter" not "per milliliter".

We all wish for a simple answer to the question, "How many PU's do I need?" but an easy answer doesn't exist as is evidenced by the frustrating "it depends".

I'm sorry to report that you need to do your own research. Define the quality of your beverages and offending microbes. Then work with an expert or a qualified supplier to design a system that you are comfortable with.

As I've said before, Dr. Werner Back at Weihenstephan has written some nice papers on this subject. Worth seeking out as a first step.

What types of microbes are your after? For example, spore formers are notoriously difficult to kill and might even be encouraged by heat treatment. Luckily, spore formers are not normally problematic in standard beers but may be important in none typical beverages. In some cases, with spore formers, a second pasteurization might be required or one pass with extremely high dose of PU's.

It also depends on the "inner stability" of your beer - % ABV, BU's, pH, Residual Extract, DO etc etc

Then one needs to consider turbidity. The presence of particles/pulp (as might be found in a fruit beer) can protect offending microbes from destruction.

If discussing Flash Pasteurization, one must take care to insure carbonation remains saturated. Gas breakout will offer protection against destruction from heat. The critical point for this is "Temperature versus Pressure" at the SUCTION side of the Booster Pump between Regeneration Sections.

Even the simple question, "How much back pressure do I need?" elicits a "it depends" response. The turbulence due to heat exchanger plate design is different between suppliers so that the required back pressure varies. And then you have to decide on a reasonable "safety factor". Then you have to consider fluctuations in system pressure as you go on stream or switch back and forth between recycle and forward flow.

It is estimated that 50% of contaminations occur in the Filling Hall. So Flash pasteurization will not protect you against re-condemnation from a dirty filler or crowner.

It is critical to remember that Pasteurization is NOT equivalent to sterilization. It is a "game of numbers". That is, pasteurization results only in a "log reduction" of micro load. Therefore it is best to not rely on pasteurization to destroy ALL offending microbes but rather to start pasteurization with a low microbiological load to improve the odds. I recommend to not rely on it to correct a beer with a high microbiological load.

I have heard stories of brewers that plate beer fresh off pasteurization and find "None Detected". But, follow up plating after a few weeks, shows regrowth from microbes that were "damaged" but not destroyed by this heat treatment.

Then, once you have a system in place, you need to take care to maintain it.

I know of many "horror stories" around failed pasteurization. Tunnel Pasteurizers with plugged spray nozzles. Flash Pasteurizers that were not properly designed or CIP'ed so that they become a source of contamination!

Like all aspects of brewing, one could spend a lifetime properly defining best practices. Sorry for the bad news.

Good Luck,

Daniel Carey

New Glarus Brewing Company

Hello Fellow Brewers,

I have watched this tread with interest and agree with the caution expressed by Alex and Jeff.

We are in a dangerous time as brewers experiment with none traditional beverages. Mike Barney, retired expert microbiologist from Miller, has long warned us about the dangers of non alcoholic beers. Now the presence of beverages with high loads of fermentable extract are truly "bombs". We need to be thinking about "cells of beer spoilers per liter" not "per milliliter".

We all wish for a simple answer to the question, "How many PU's do I need?" but an easy answer doesn't exist as is evidenced by the frustrating "it depends".

I'm sorry to report that you need to do your own research. Define the quality of your beverages and offending microbes. Then work with an expert or a qualified supplier to design a system that you are comfortable with.

As I've said before, Dr. Werner Back at Weihenstephan has written some nice papers on this subject. Worth seeking out as a first step.

What types of microbes are your after? For example, spore formers are notoriously difficult to kill and might even be encouraged by heat treatment. Luckily, spore formers are not normally problematic in standard beers but may be important in none typical beverages. In some cases, with spore formers, a second pasteurization might be required or one pass with extremely high dose of PU's.

It also depends on the "inner stability" of your beer - % ABV, BU's, pH, Residual Extract, DO etc etc

Then one needs to consider turbidity. The presence of particles/pulp (as might be found in a fruit beer) can protect offending microbes from destruction.

If discussing Flash Pasteurization, one must take care to insure carbonation remains saturated. Gas breakout will offer protection against destruction from heat. The critical point for this is "Temperature versus Pressure" at the SUCTION side of the Booster Pump between Regeneration Sections.

Even the simple question, "How much back pressure do I need?" elicits a "it depends" response. The turbulence due to heat exchanger plate design is different between suppliers so that the required back pressure varies. And then you have to decide on a reasonable "safety factor". Then you have to consider fluctuations in system pressure as you go on stream or switch back and forth between recycle and forward flow.

It is estimated that 50% of contaminations occur in the Filling Hall. So Flash pasteurization will not protect you against re-condemnation from a dirty filler or crowner.

It is critical to remember that Pasteurization is NOT equivalent to sterilization. It is a "game of numbers". That is, pasteurization results only in a "log reduction" of micro load. Therefore it is best to not rely on pasteurization to destroy ALL offending microbes but rather to start pasteurization with a low microbiological load to improve the odds. I recommend to not rely on it to correct a beer with a high microbiological load.

I have heard stories of brewers that plate beer fresh off pasteurization and find "None Detected". But, follow up plating after a few weeks, shows regrowth from microbes that were "damaged" but not destroyed by this heat treatment.

Then, once you have a system in place, you need to take care to maintain it.

I know of many "horror stories" around failed pasteurization. Tunnel Pasteurizers with plugged spray nozzles. Flash Pasteurizers that were not properly designed or CIP'ed so that they become a source of contamination!

Like all aspects of brewing, one could spend a lifetime properly defining best practices. Sorry for the bad news.

Good Luck,

Daniel Carey

New Glarus Brewing Company

Hello Fellow Brewers,

I have watched this tread with interest and agree with the caution expressed by Alex and Jeff.

We are in a dangerous time as brewers experiment with none traditional beverages. Mike Barney, retired expert microbiologist from Miller, has long warned us about the dangers of non alcoholic beers. Now the presence of beverages with high loads of fermentable extract are truly "bombs". We need to be thinking about "cells of beer spoilers per liter" not "per milliliter".

We all wish for a simple answer to the question, "How many PU's do I need?" but an easy answer doesn't exist as is evidenced by the frustrating "it depends".

I'm sorry to report that you need to do your own research. Define the quality of your beverages and offending microbes. Then work with an expert or a qualified supplier to design a system that you are comfortable with.

As I've said before, Dr. Werner Back at Weihenstephan has written some nice papers on this subject. Worth seeking out as a first step.

What types of microbes are your after? For example, spore formers are notoriously difficult to kill and might even be encouraged by heat treatment. Luckily, spore formers are not normally problematic in standard beers but may be important in none typical beverages. In some cases, with spore formers, a second pasteurization might be required or one pass with extremely high dose of PU's.

It also depends on the "inner stability" of your beer - % ABV, BU's, pH, Residual Extract, DO etc etc

Then one needs to consider turbidity. The presence of particles/pulp (as might be found in a fruit beer) can protect offending microbes from destruction.

If discussing Flash Pasteurization, one must take care to insure carbonation remains saturated. Gas breakout will offer protection against destruction from heat. The critical point for this is "Temperature versus Pressure" at the SUCTION side of the Booster Pump between Regeneration Sections.

Even the simple question, "How much back pressure do I need?" elicits a "it depends" response. The turbulence due to heat exchanger plate design is different between suppliers so that the required back pressure varies. And then you have to decide on a reasonable "safety factor". Then you have to consider fluctuations in system pressure as you go on stream or switch back and forth between recycle and forward flow.

It is estimated that 50% of contaminations occur in the Filling Hall. So Flash pasteurization will not protect you against re-condemnation from a dirty filler or crowner.

It is critical to remember that Pasteurization is NOT equivalent to sterilization. It is a "game of numbers". That is, pasteurization results only in a "log reduction" of micro load. Therefore it is best to not rely on pasteurization to destroy ALL offending microbes but rather to start pasteurization with a low microbiological load to improve the odds. I recommend to not rely on it to correct a beer with a high microbiological load.

I have heard stories of brewers that plate beer fresh off pasteurization and find "None Detected". But, follow up plating after a few weeks, shows regrowth from microbes that were "damaged" but not destroyed by this heat treatment.

Then, once you have a system in place, you need to take care to maintain it.

I know of many "horror stories" around failed pasteurization. Tunnel Pasteurizers with plugged spray nozzles. Flash Pasteurizers that were not properly designed or CIP'ed so that they become a source of contamination!

Like all aspects of brewing, one could spend a lifetime properly defining best practices. Sorry for the bad news.

Good Luck,

Daniel Carey

New Glarus Brewing Company

Hello Fellow Brewers,

I have watched this tread with interest and agree with the caution expressed by Alex and Jeff.

We are in a dangerous time as brewers experiment with none traditional beverages. Mike Barney, retired expert microbiologist from Miller, has long warned us about the dangers of non alcoholic beers. Now the presence of beverages with high loads of fermentable extract are truly "bombs". We need to be thinking about "cells of beer spoilers per liter" not "per milliliter".

We all wish for a simple answer to the question, "How many PU's do I need?" but an easy answer doesn't exist as is evidenced by the frustrating "it depends".

I'm sorry to report that you need to do your own research. Define the quality of your beverages and offending microbes. Then work with an expert or a qualified supplier to design a system that you are comfortable with.

As I've said before, Dr. Werner Back at Weihenstephan has written some nice papers on this subject. Worth seeking out as a first step.

What types of microbes are your after? For example, spore formers are notoriously difficult to kill and might even be encouraged by heat treatment. Luckily, spore formers are not normally problematic in standard beers but may be important in none typical beverages. In some cases, with spore formers, a second pasteurization might be required or one pass with extremely high dose of PU's.

It also depends on the "inner stability" of your beer - % ABV, BU's, pH, Residual Extract, DO etc etc

Then one needs to consider turbidity. The presence of particles/pulp (as might be found in a fruit beer) can protect offending microbes from destruction.

If discussing Flash Pasteurization, one must take care to insure carbonation remains saturated. Gas breakout will offer protection against destruction from heat. The critical point for this is "Temperature versus Pressure" at the SUCTION side of the Booster Pump between Regeneration Sections.

Even the simple question, "How much back pressure do I need?" elicits a "it depends" response. The turbulence due to heat exchanger plate design is different between suppliers so that the required back pressure varies. And then you have to decide on a reasonable "safety factor". Then you have to consider fluctuations in system pressure as you go on stream or switch back and forth between recycle and forward flow.

It is estimated that 50% of contaminations occur in the Filling Hall. So Flash pasteurization will not protect you against re-condemnation from a dirty filler or crowner.

It is critical to remember that Pasteurization is NOT equivalent to sterilization. It is a "game of numbers". That is, pasteurization results only in a "log reduction" of micro load. Therefore it is best to not rely on pasteurization to destroy ALL offending microbes but rather to start pasteurization with a low microbiological load to improve the odds. I recommend to not rely on it to correct a beer with a high microbiological load.

I have heard stories of brewers that plate beer fresh off pasteurization and find "None Detected". But, follow up plating after a few weeks, shows regrowth from microbes that were "damaged" but not destroyed by this heat treatment.

Then, once you have a system in place, you need to take care to maintain it.

I know of many "horror stories" around failed pasteurization. Tunnel Pasteurizers with plugged spray nozzles. Flash Pasteurizers that were not properly designed or CIP'ed so that they become a source of contamination!

Like all aspects of brewing, one could spend a lifetime properly defining best practices. Sorry for the bad news.

Good Luck,

Daniel Carey

New Glarus Brewing Company