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Heat and Hold: A Critical Step in Beverage Batch Pasteurizers

PRO Engineering / Manufacturing Inc.

Introduction

  • Explanation of the importance of understanding the pasteurization process for beer and non-dairy beverages.
  • Brief introduction to the concept of heat and hold in pasteurization.

Pasteurization Process Overview

  • Simple explanation of the pasteurization process.
  • Importance of heating to a specific temperature to destroy harmful microorganisms and enzymes.
  • Explanation of the cooling process following the heat and hold method.

Importance of Heat and Hold

  • Role of heating in ensuring product safety by destroying pathogens.
  • The necessity of holding the temperature to maintain beverage quality.

Components of Batch Pasteurizers

  • Heating system: Raises the product to pasteurization temperatures.
  • Holding tube: Ensures product remains at the temperature for the required time.
  • Pump: Circulates the product through the pasteurization unit.
  • Cooling system: Cools the product post-pasteurization.
  • Explanation of each component’s role in ensuring product safety and quality.

Temperature Control Mechanisms

  • Description of the sophisticated temperature control systems in batch pasteurizers.
  • Importance of maintaining desired temperature levels throughout the pasteurization cycle.

Advantages of Batch Pasteurization

  • Insight into the benefits of batch pasteurization for beverage production.
  • Discussion on how batch pasteurization promotes shelf life, taste, and nutrient retention.
  • Advantages in monitoring temperature, handling different container sizes, and enhancing product quality.

Most Frequently Asked Questions

  • Can batch pasteurizers handle more than one type of beverage at once?
  • The impact of the size of the batch pasteurizer on the process.
  • Additional safety steps for operating batch pasteurizers.
  • Common issues in pasteurizing non-dairy beverages and how to address them.

Conclusion

  • Recap of the importance of heat and hold in the pasteurization process.
  • Final thoughts on how understanding these processes can lead to successful beverage pasteurization and ensuring product safety and quality.

Tune in to unravel the intricate relationship between temperature and time in batch pasteurizers, a vital duo in perfecting your favorite beverages.

Introduction

The intricate nature of the meticulous processes in beer and non-dairy beverage pasteurizing calls for a thorough understanding of the mechanics of heat and hold. Before you understand this essential stage of the process that will inform you of the perfect conditions for the product’s safety and quality, you should picture the harmonious interplay of heat and the length of pasteurization, two elements that determine whether your favorite drink is safe for consumption or not.

How do such batch pasteurizers work to guarantee the safety and quality of that beer or beverage? Let’s explore below.

Pasteurization Process Overview

This process’s simple explanation will help you understand the fundamental process necessary to retain the beer and other beverages’ safety and quality. Pasteurization is a critical process in which the liquid is heated to a specific temperature to destroy harmful microorganisms and enzymes. However, the liquid is then held at that temperature for a specific period before being cooled quickly. The heat used and retained in the process helps kill pathogens while preserving all the flavor and the drink quality.

Importance of Heat and Hold

The Heating Phase

The first step in pasteurization is the heating of the beverage, a process fundamental to the destruction of pathogens. By elevating the beverage’s temperature to a targeted range, typically between 60°C and 85°C, for a specified duration, harmful microorganisms such as yeasts, molds, and bacteria are effectively eradicated. This selection of temperature and duration is critical, designed to maximize pathogen deactivation without compromising the beverage’s integrity.

The basis for this careful selection lies in the thermal sensitivity of pathogens, with each species having a specific survival threshold temperature. Consequently, the heating phase serves a dual purpose: sterilizing the beverage and preventing potential spoilage by eliminating microbial activity, thereby extending the product’s shelf life.

The Holding Phase

Following the heating step, the holding phase is equally critical to the pasteurization process. Achieving the target temperature necessitates maintaining it to allow the heat to uniformly penetrate the beverage. This uniformity is vital to ensure no part of the beverage remains at a non-lethal temperature, which could otherwise harbor surviving microbes. The holding time is determined by the specifics of the beverage, the type of microorganisms present, and the general time-temperature relationship depicted in thermal death time curves.

This phase not only ensures the death of all harmful microbes but also plays a crucial role in preserving the quality of the beverage. Rapid heating followed by prolonged exposure to high temperatures can degrade the sensory and nutritional characteristics of the product, such as flavor, color, and vitamins. Thus, the holding phase is finely tuned to balance sterilization with the preservation of product quality, with modern pasteurization techniques closely monitoring and adjusting temperatures to prevent heat damage.

Components: Heating, Holding Tube, Pump, Cooling System

Regardless of the specific batch pasteurizer used, most of them have the same components:

  • The Heating System raises the temperature of the product to pasteurization temperatures.
  • The Holding Tube ensures the product stays at temperature for the required time to eliminate effective bacteria.
  • Pump is used to circulate the product through the pasteurization unit.
  • Cooling system cools the product immediately after pasteurization.

Each component has a role to play in ensuring the product is properly pasteurized and the final product is of high quality and safe.

Temperature Control Mechanisms

To ensure precise pasteurization processes, understanding the temperature control mechanisms is imperative when operating batch pasteurizers. These mechanisms play a crucial role in maintaining the desired temperature levels throughout the pasteurization cycle.

Most batch pasteurizers are equipped with advanced temperature control systems that regulate the heating and cooling processes with great accuracy. By monitoring and adjusting the temperature settings, you can ensure that the beverages are pasteurized effectively without compromising their quality.

The temperature control mechanisms also help in preventing overheating or underheating, which could lead to inadequate pasteurization or even spoilage. Therefore, mastering the temperature control features of batch pasteurizers is essential for producing safe and high-quality beverages consistently.

The Advantages of “Batch Pasteurization”

Knowing the benefits of “batch pasteurization” will give you an insight into the efficiency and effectiveness of your beverage production. Batch pasteurization helps promote your product’s shelf life without compromising the final taste and nutrients. It allows you to monitor the temperature effectively, ensuring the desired pasteurization levels are met batch after batch.

Additionally, batch pasteurizers can manage different container sizes and types, making them perfect for varying production scales. By adopting batch pasteurization, you can smoothen and fasten your production process, minimize contamination, and enhance your product’s quality.

Understanding the advantages of batch pasteurization can provide valuable insights into the efficiency and quality of beverage production. By utilizing batch pasteurizers, you can ensure that your beer or non-dairy beverages are safe for consumption by eliminating harmful bacteria and pathogens. Batch pasteurization also helps in extending the shelf life of your products without compromising their taste or nutritional value.

This method allows for precise temperature control, ensuring that the desired pasteurization levels are consistently met batch after batch. Additionally, batch pasteurizers are versatile and can accommodate different container sizes and types, making them suitable for various production scales. Embracing batch pasteurization can streamline your production process, reduce risks of contamination, and ultimately enhance the overall quality of your beverages.

Most Frequently Asked Questions

Can Batch Pasteurizers Pasteurize More Than One Type of Beverage at Once?

Yes, batch pasteurizers can efficiently pasteurize multiple types of beverages simultaneously. They provide consistent heating and holding temperatures for various drinks, ensuring uniform pasteurization across different batches, saving time and resources.

Batch pasteurizers are designed to handle different beverage types effectively, making them a versatile solution for businesses looking to streamline their pasteurization process. By accommodating multiple products at once, these machines can improve efficiency and productivity in beverage production.

How Does the Size of the Batch Pasteurizer Affect the Process?
When choosing a batch pasteurizer, consider how the size impacts pasteurization. Smaller units may heat up faster but have limited capacity. Larger ones can handle more volume but might require longer processing times.

Are there any additional safety steps that need to be taken regularly while operating a batch pasteurizer?

When operating a batch pasteurizer, always follow safety measures:
Wear protective gear, ensure proper ventilation, and never bypass safety features. Regular maintenance checks and staff training are vital. Prioritize safety to prevent accidents.

What are the common issues that may arise when pasteurizing non-dairy beverages in a batch pasteurizer?

When using batch pasteurizers for non-dairy beverages, you may face challenges like:

  • Maintaining precise temperatures
    • Ensuring uniform heating
    • Preventing product scorching
    • Stay vigilant with monitoring and adjustments to overcome these obstacles effectively.
    • Make sure to keep a close eye on these factors to ensure the quality and safety of your non-dairy beverages.

How Does the Pasteurization Process Impact the Flavor and Texture of the Final Product?

  • When pasteurizing, the process impacts the flavor and texture of your final product. Heat can alter taste and mouthfeel, but it also ensures safety.
  • Holding at specific temperatures balances these changes for a product that’s both safe and delicious.

Conclusion

The “heat and hold” phase is indispensable in the pasteurization process, ensuring the safety and quality of beverages. Through the meticulous application of heating and holding, harmful microbes are eradicated while preserving the beverage’s sensory and nutritional qualities. This paper highlights the importance of understanding these phases to appreciate their role in producing safe, high-quality beverages.

RESOURCES:

1. Brewers Association – The Brewers Association is a non-profit organization that promotes and protects small and independent American brewers. Their website offers resources, articles, and guides related to craft brewing techniques, including pasteurization. Website: Brewers Association

2. Craft Brewing Business – Craft Brewing Business is a trade publication dedicated to the craft brewing industry. They cover various topics related to craft brewing, including techniques, equipment, and industry news. Website: Craft Brewing Business

3. American Society of Brewing Chemists (ASBC) – ASBC is a professional organization that provides resources and standards for brewing science and technology. Their website includes research articles, publications, and technical resources related to brewing techniques. Website: American Society of Brewing Chemists

4. Brewing Science Institute – The Brewing Science Institute offers educational resources and training programs for brewers. Their website includes articles, webinars, and courses covering various aspects of brewing science and technology. Website: Brewing Science Institute

5. Master Brewers Association of the Americas (MBAA) – MBAA is a professional association for brewers, brewing engineers, and industry professionals. Their website provides technical resources, publications, and educational materials related to brewing techniques. Website: Master Brewers Association of the Americas

6. Brewing Industry Guide – The Brewing Industry Guide is an online resource for brewers, providing articles, guides, and industry insights on brewing practices and technologies. Website: Brewing Industry Guide

ABOUT PRO ENGINEERING / MANUFACTURING INC.

Trusted | Knowledge | Quality

We have been involved in pasteurizers since 1977.

PRO Engineering / Manufacturing Inc. has developed a range of small, medium, and large-sized tunnel & batch pasteurizers to fit the needs of BrewMasters and Beverage Makers. When our customers asked for more compact as well as full-size tunnel pasteurizers, PRO developed models to fit our customers’ needs. Then our customers needed a batch pasteurizer. We now provide batch pasteurizers; PRO is a business that continually innovates to meet customer needs.

For more than 40 years, we have been delivering solutions for beverage product shelf stability and consumption safety.

Edward A. Michalski CEO

Ed Michalski started his career in the beverage industry by designing stainless steel, higher flow, spray headers for Pabst Brewing. Along with the header design he also developed a process to produce the new headers.

Ed, along with his brother David, formed PRO Engineering / Manufacturing Inc. Based on what they learned by re-designing and refurbishing other manufacturers’ pasteurizers, Ed and PRO started to offer the pasteurizer marketplace superior new pasteurizers. PRO Engineering / Manufacturing Inc. has been designing and manufacturing great pasteurizers for over four decades.

For more information on tunnel and batch pasteurization contact PRO Engineering / Manufacturing, Inc. at [email protected] or call (414) 362-1500 and ask for Ed Michalski, CEO.

Partner with a PRO!… PRO Engineering / Manufacturing Inc.

Internal Resources:

Safety First: Understanding the Importance of Pasteurization in Beer Production

Introduction

  • Brief overview of the beer production process
  • Importance of safety measures in the brewing industry

What is Pasteurization?

  • Definition and origins of pasteurization
  • How pasteurization works

Pasteurization in Beer Production

  • Reasons for pasteurizing beer
  • Key benefits of pasteurization
    • Microbiological stability
    • Extended shelf life
    • Consistency in flavor and quality
  • Common misconceptions about pasteurization in beer

Ensuring Safety and Quality

  • Contaminants and risks in beer production
  • Impact of contaminated beer on consumer health
  • Regulatory requirements and guidelines for pasteurization

Difference Between Tunnel and Batch Pasteurizers

  • Operation
  • Throughput and Capacity
  • Flexibility
  • Quality

Challenges and Considerations

  • Balancing safety with flavor profiles
  • Alternative methods to pasteurization

Industry Perspectives and Best Practices

  • Insights from breweries employing pasteurization
  • Case studies: Success stories and lessons learned
  • Emerging trends and innovations in beer pasteurization

Conclusion

  • Recap of the importance of pasteurization in beer production
  • Call to prioritize safety in the brewing industry
  • Future prospects and the role of technology in enhancing safety measures

Introduction

Beer, one of the world’s oldest and most beloved beverages, undergoes a complex production process before reaching our glasses. Beyond the craftsmanship and artistry involved, ensuring the safety and quality of beer is paramount. One crucial aspect of this process is pasteurization, a method that plays a pivotal role in preserving beer and protecting consumers from potential health risks.

What is Pasteurization?

Pasteurization, named after the renowned French scientist Louis Pasteur, is a heat treatment process used to eliminate or reduce microorganisms in food and beverages. Initially developed in the 19th century to prevent spoilage in wine, pasteurization has become a vital technique employed in various industries, including beer production.

Pasteurization in Beer Production

Reasons for Pasteurizing Beer

The primary objective of pasteurization in beer production is to ensure microbiological stability. By subjecting the beer to heat, harmful microorganisms such as bacteria, yeast, and mold are eliminated or rendered inactive, preventing spoilage and maintaining product quality.

Key Benefits of Pasteurization

Microbiological Stability: Pasteurization safeguards beer from contamination, preserving its freshness and taste throughout its shelf life.

Extended Shelf Life: Pasteurized beer can have a longer shelf life, reducing waste and enhancing distribution possibilities.

Consistency in Flavor and Quality: Pasteurization helps maintain a consistent flavor profile, ensuring that consumers can enjoy the same high-quality beer with every purchase.

Common Misconceptions about Pasteurization in Beer

Some beer enthusiasts argue that pasteurization negatively affects the taste and aroma of beer, believing that it destroys delicate flavors and aromatics. However, advancements in technology and meticulous temperature control have mitigated these concerns, allowing breweries to strike a balance between safety and flavor preservation.

Ensuring Safety and Quality

Contaminants and Risks in Beer Production

Beer production can be susceptible to various contaminants, including microorganisms, spoilage bacteria, and yeast and mold. These contaminants pose significant health risks if present in the final product.

Impact of Contaminated Beer on Consumer Health

Consuming contaminated beer can lead to foodborne illnesses and adverse health effects. It is essential for breweries to prioritize safety measures to protect their consumers and maintain their reputation.

Regulatory Requirements and Guidelines for Pasteurization

To ensure consumer safety, regulatory bodies impose stringent guidelines and standards on breweries. Pasteurization is often a mandatory step in the beer production process, and breweries must adhere to these regulations to bring safe and high-quality products to market.

Difference Between Tunnel and Batch Pasteurizers

Tunnel pasteurizers and batch pasteurizers are two common methods used for the pasteurization of food and beverages. While both processes aim to eliminate harmful microorganisms, there are significant differences in their operation and applications.

Operation:

Tunnel Pasteurizers: These are continuous pasteurization systems designed to process products in a continuous flow. The products move through a temperature-controlled tunnel on a conveyor belt or carrier system. Hot water, steam, or a combination of both is used to heat the product to the desired pasteurization temperature, followed by a cooling stage to bring it back to ambient temperature.

Batch Pasteurizers: As the name suggests, batch pasteurizers operate in batches or discrete cycles. The product is loaded into a container or vessel, which is then heated to the pasteurization temperature. Once the desired temperature is reached, the product is held at that temperature for a specified duration to achieve the required level of pasteurization. Afterward, the product is cooled before unloading and the next batch begins.

Throughput and Capacity:

Tunnel Pasteurizers: Due to their continuous operation, tunnel pasteurizers are capable of high throughput and are often used for large-scale production. They are suitable for processing large volumes of packaged products, such as bottles, cans, or jars.

Batch Pasteurizers: Batch pasteurizers have a limited capacity as they process a fixed volume of product per cycle. They are typically used for smaller production volumes or for products that cannot be effectively processed in a continuous flow, such as certain dairy products or specialty beverages.

Flexibility:

Tunnel Pasteurizers: Tunnel pasteurizers offer less flexibility in terms of process customization. They are designed to provide consistent and standardized pasteurization conditions for a wide range of products. Adjusting the parameters for different products may require significant changes to the equipment setup.

Batch Pasteurizers: Batch pasteurizers offer more flexibility as they can be adjusted to accommodate different products and process requirements. The temperature, holding time, and other parameters can be customized for each batch, making them suitable for smaller-scale or niche production.

Product Quality:

Tunnel Pasteurizers: Continuous tunnel pasteurization provides a uniform heat treatment to the entire product batch, ensuring consistent pasteurization and product quality. The continuous flow also minimizes the potential for temperature variations.

Batch Pasteurizers: Batch pasteurization may have slightly more variation in temperature and pasteurization levels within the same batch, which could potentially affect product quality. However, careful monitoring and control can minimize these variations, especially in modern batch pasteurization systems.

In summary, tunnel pasteurizers are continuous systems suitable for high-volume production, offering standardized pasteurization conditions. Batch pasteurizers, on the other hand, operate in discrete cycles, providing flexibility for smaller-scale production and customizable pasteurization parameters. The choice between the two depends on factors such as production volume, product characteristics, and desired process control.

Challenges and Considerations

Balancing Safety with Flavor Profiles

Achieving a balance between safety and flavor is a critical consideration for breweries. It requires careful optimization of pasteurization processes to minimize flavor and aroma alterations while effectively eliminating harmful microorganisms.

Alternative Methods to Pasteurization

While pasteurization is the conventional method for ensuring beer safety, alternative techniques such as cold filtration and UV treatment have gained traction. These methods offer potential advantages, but they also come with their own set of challenges and limitations.

Pros and Cons of Different Approaches

Understanding the pros and cons of various pasteurization methods allows breweries to make informed decisions based on their specific requirements, product characteristics, and consumer preferences.

Industry Perspectives and Best Practices

Insights from Breweries Employing Pasteurization

Breweries that have successfully implemented pasteurization share their experiences and best practices, shedding light on the benefits, challenges, and potential improvements in the process.

Case Studies: Success Stories and Lessons Learned

Examining specific case studies of breweries that have effectively utilized pasteurization can provide valuable insights into the practical application of pasteurization and its impact on product quality, shelf life, and consumer satisfaction.

Emerging Trends and Innovations in Beer Pasteurization

The brewing industry is continuously evolving, and advancements in technology are driving innovation in pasteurization methods. From novel heat exchange systems to automated control systems, breweries are exploring new ways to enhance the efficiency, precision, and effectiveness of pasteurization while minimizing flavor impact.

Conclusion

In the brewing industry, prioritizing safety through pasteurization is a crucial responsibility. By understanding the importance of pasteurization in beer production, breweries can ensure microbiological stability, extend the shelf life of their products, and maintain consistent quality and flavor profiles. While there may be concerns about flavor alterations, advancements in pasteurization technology have addressed these issues, allowing breweries to strike a harmonious balance between safety and taste.

By placing safety first and understanding the vital role of pasteurization, the brewing industry can continue to thrive, delighting consumers with flavorful, safe, and high-quality beers for generations to come.

RESOURCES:

Brink, D. L., & Seman, D. L. (2007). Pasteurization. In Encyclopedia of Agricultural, Food, and Biological Engineering (pp. 1-4). Taylor & Francis.

Brewbound. (2021). Cold Filtration: The Alternative to Pasteurization. Retrieved from https://www.brewbound.com/

European Brewery Convention. (2021). Pasteurization. In EBC Analysis Method. Retrieved from https://brewup.eu

Molina-Ramirez, C., Hernandez-Iturriaga, M., Cerna-Cortes, J., Castillo-Castaneda, P., Perez-Urquiaga, M. A., & Alarcon-Rojo, A. D. (2019). Sensory quality and volatile compounds in beer pasteurized by tunnel or flash processes. Journal of the Institute of Brewing, 125(3), 249-257.

Pinto, F. R., Geraldes, V., Almeida, C., Ferreira, I. M., Bernardo, F., & Nunes, J. C. (2018). Effect of UV treatment on beer quality parameters. Journal of the Institute of Brewing, 124(4), 474-479.

Silva, T. M., Bernardes, L. P., & Teixeira, J. A. (2021). A review on cold pasteurization of beer: current and future trends. Frontiers in Nutrition, 8, 633776.

Thrall, K. (2018). Pasteurization: An Essential Safety Measure for the Brewing Industry. Craft Beer and Brewing Magazine. Retrieved from https://beerandbrewing.com/

Learn More About Tunnel and Batch Pasteurizing to Maximize Profits!

ABOUT PRO ENGINEERING / MANUFACTURING INC.

Trusted | Knowledge | Quality

We have been involved in pasteurizers since 1977.

PRO Engineering / Manufacturing Inc. has developed a range of small, medium, and large-sized tunnel & batch pasteurizers to fit the needs of BrewMasters and Beverage Makers. When our customers asked for more compact as well as full-size tunnel pasteurizers, PRO developed models to fit our customers’ needs. Then our customers needed a batch pasteurizer. We now provide batch pasteurizers; PRO is a business that continually innovates to meet customer needs.

For more than 40 years, we have been delivering solutions for beverage product shelf stability and consumption safety.

Edward A. Michalski CEO

Ed Michalski started his career in the beverage industry by designing stainless steel, higher flow, spray headers for Pabst Brewing. Along with the header design he also developed a process to produce the new headers.

Ed, along with his brother David, formed PRO Engineering / Manufacturing Inc. Based on what they learned by re-designing and refurbishing other manufacturers’ pasteurizers, Ed and PRO started to offer the pasteurizer marketplace superior new pasteurizers. PRO Engineering / Manufacturing Inc. has been designing and manufacturing great pasteurizers for over four decades.

For more information on tunnel and batch pasteurization contact PRO Engineering / Manufacturing, Inc. at [email protected] or call (414) 362-1500 and ask for Ed Michalski, CEO.

Partner with a PRO!… PRO Engineering / Manufacturing Inc.

Internal Resources:

From Brew to Bottle: The Journey of Pasteurized Beer… Batch VS Tunnel Pasteurization

Introduction

  • Definition of pasteurization in the context of beer production
  • Significance of pasteurization in preserving beer quality and extending shelf life

The Brewing Process

  • Overview of the beer brewing process
  • Importance of sanitation and microbial control in brewing

Pasteurization Methods

  • Explanation of batch pasteurization
    • Description of batch pasteurizers and their operation
    • Advantages and limitations of batch pasteurization
  • Discussion of tunnel pasteurization
    • Description of tunnel pasteurizers and their components
    • Step-by-step process of tunnel pasteurization
    • Benefits and challenges associated with tunnel pasteurization

The Journey of Pasteurized Beers

  • Pre-pasteurization handling and preparation
    • Filtering and clarification
    • Carbonation and packaging considerations
  • Batch pasteurization process
    • Loading and heating the pasteurizer
    • Holding and cooling stages
  • Tunnel pasteurization process
    • Conveyor belt and temperature control
    • Heat treatment zones and dwell times
  • Post-pasteurization procedures
    • Quality control measures
    • Packaging and distribution

Benefits and Challenges of Pasteurization

  • Advantages of pasteurized beers
    • Increased shelf life and stability
    • Reduction of microbial contamination risks
  • Potential drawbacks and considerations
    • Flavor and aroma impact
    • Additional equipment and operational costs

Industry Trends and Innovations

  • Advancements in pasteurization technology
  • Emergence of alternative preservation methods
    • Cold filtration techniques
    • Non-thermal pasteurization methods

Conclusion

  • Recap of the journey of pasteurized beers from brew to bottle
  • Significance of pasteurization in ensuring beer quality and safety
  • Future prospects and potential developments in the field

Introduction

Beer, a beloved beverage enjoyed by many, undergoes a meticulous process from the brewery to the bottle. One crucial step in this journey is pasteurization. Pasteurization plays a significant role in preserving beer quality, extending its shelf life, and ensuring that it reaches consumers in optimal condition. In this article, we will explore the journey of pasteurized beers, focusing on the two primary methods of pasteurization: batch pasteurizers and tunnel pasteurizers.

The Brewing Process

Before delving into the intricacies of pasteurization, it’s essential to understand the beer brewing process as a whole. Brewing involves several steps, including malting, mashing, boiling, fermentation, and conditioning. Throughout this process, maintaining proper sanitation and microbial control is crucial to prevent any undesirable flavors or contamination.

Pasteurization Methods

Batch Pasteurization:

Batch pasteurization is a traditional method that involves heating packaged beer to a specific temperature for a predetermined duration. Batch pasteurizers typically consist of heating chambers and conveyors. The beer is loaded into the pasteurizer and heated, after which it is cooled and then released for packaging. While batch pasteurization is a well-established method, it has some limitations, such as longer processing times and higher labor requirements.

Tunnel Pasteurization:

Tunnel pasteurization, on the other hand, is a continuous process conducted in a tunnel-like machine. The beer bottles or cans move through the tunnel on a conveyor belt, passing through various temperature zones. Each zone is carefully controlled to ensure proper heat treatment. Tunnel pasteurizers offer faster processing times and higher efficiency compared to batch pasteurizers. However, they require significant initial investment and meticulous control to maintain consistent quality.

The Journey of Pasteurized Beers

Pre-pasteurization Handling and Preparation:

Before pasteurization, the beer goes through several essential steps. These include filtering and clarification to remove any sediment or impurities. Carbonation and packaging considerations are also addressed to ensure the beer’s quality and desired characteristics are maintained.

Batch Pasteurization Process:

In batch pasteurization, the beer is loaded into the pasteurizer, where it is heated to a specific temperature. This temperature effectively kills any potential harmful microorganisms. The beer is then held at that temperature for a predetermined time before being rapidly cooled. This process helps ensure the beer’s stability and extends its shelf life.

Tunnel Pasteurization Process:

Tunnel pasteurization involves a conveyor belt system that transports the beer through the tunnel pasteurizer. The temperature in each heat treatment zone is carefully controlled to eliminate any spoilage microorganisms while minimizing the impact on beer flavor. The dwell time in each zone is precisely calculated to achieve the desired level of pasteurization.

Post-pasteurization Procedures:

After pasteurization, quality control measures are taken to verify the beer’s microbiological stability and overall quality. Packaging, labeling, and distribution follow, ensuring that the pasteurized beer reaches consumers in a safe and consistent state.

Benefits and Challenges of Pasteurization

Pasteurization provides several advantages for beers:

Increased Shelf Life and Stability: Pasteurization extends the beer’s shelf life, allowing it to maintain its quality and freshness over an extended period.

Reduction of Microbial Contamination Risks: Pasteurization helps eliminate harmful microorganisms, reducing the risk of spoilage and potential health hazards.

However, there are considerations to keep in mind:

Flavor and Aroma Impact: Pasteurization can have a subtle impact on the beer’s flavor and aroma, which must be carefully managed to maintain the desired sensory profile of the beer.

Additional Equipment and Operational Costs: Implementing pasteurization requires specific equipment, such as pasteurizers and temperature control systems. These additional investments and operational costs need to be taken into account by breweries considering pasteurization.

As the beer industry evolves, advancements in pasteurization technology continue to emerge. Manufacturers are developing more efficient and precise pasteurizers, optimizing temperature control and reducing processing times. These advancements aim to enhance the pasteurization process while minimizing any potential negative effects on the beer’s quality.

Furthermore, alternative preservation methods are gaining attention. Cold filtration techniques, such as membrane filtration, provide an alternative to pasteurization by removing microorganisms without the need for heat treatment. Additionally, non-thermal pasteurization methods, such as high-pressure processing or ultraviolet light treatment, offer innovative approaches to ensure beer safety and stability while minimizing flavor impact.

Conclusion

The journey of pasteurized beers from brew to bottle involves crucial steps to preserve quality, extend shelf life, and ensure consumer safety. Batch and tunnel pasteurizers play a vital role in this process, each with its advantages and challenges. While pasteurization offers significant benefits, breweries must carefully manage factors such as flavor impact and additional costs.

With the continuous advancements in pasteurization technology and the emergence of alternative preservation methods, the beer industry is poised to explore innovative approaches to maintaining beer quality and safety. As consumers’ expectations evolve, breweries must adapt to these trends while staying true to the craftsmanship and flavor that make beer a beloved beverage.

By embracing the journey of pasteurized beers and staying at the forefront of technological advancements, breweries can ensure that their products consistently deliver a delightful drinking experience from the first sip to the last. Cheers to the science and artistry of pasteurization in the world of beer!

RESOURCES:

Brewer’s Association www.brewersassociation.org

The official website of the Brewers Association provides industry insights, technical resources, and publications related to brewing processes, including pasteurization.

The American Society of Brewing Chemists (ASBC) www.asbcnet.org

ASBC is a professional organization dedicated to brewing science and provides resources and publications related to various aspects of brewing, including pasteurization.

Master Brewers Association of the Americas (MBAA) www.mbaa.com

MBAA is another reputable organization focused on brewing science and provides technical resources and publications that cover various topics in brewing, including pasteurization.

The Institute of Brewing and Distilling (IBD) www.ibd.org.uk

IBD offers technical resources, publications, and articles related to brewing and distilling, including information on pasteurization.

The Brewing Science Institute (BSI) www.brewingscience.com

BSI provides technical support and consulting services to the brewing industry. Their website includes informative articles and resources related to brewing processes, including pasteurization.

“Brewing: Science and Practice” by Dennis E. Briggs, Chris A. Boulton, Peter A. Brookes, and Roger Stevens.

“Principles of Brewing Science: A Study of Serious Brewing Issues” by George J. Fix.

“Technology Brewing and Malting” by Wolfgang Kunze.

“Handbook of Brewing: Processes, Technology, Markets” edited by Hans Michael Eßlinger.

“The Oxford Companion to Beer” edited by Garrett Oliver.

Learn More About Tunnel and Batch Pasteurizing to Maximize Profits!

ABOUT PRO ENGINEERING / MANUFACTURING INC.

Trusted | Knowledge | Quality

We have been involved in pasteurizers since 1977.

PRO Engineering / Manufacturing Inc. has developed a range of small, medium, and large-sized tunnel & batch pasteurizers to fit the needs of BrewMasters and Beverage Makers. When our customers asked for more compact as well as full-size tunnel pasteurizers, PRO developed models to fit our customers’ needs. Then our customers needed a batch pasteurizer. We now provide batch pasteurizers; PRO is a business that continually innovates to meet customer needs.

For more than 40 years, we have been delivering solutions for beverage product shelf stability and consumption safety.

Edward A. Michalski CEO

Ed Michalski started his career in the beverage industry by designing stainless steel, higher flow, spray headers for Pabst Brewing. Along with the header design he also developed a process to produce the new headers.

Ed, along with his brother David, formed PRO Engineering / Manufacturing Inc. Based on what they learned by re-designing and refurbishing other manufacturers’ pasteurizers, Ed and PRO started to offer the pasteurizer marketplace superior new pasteurizers. PRO Engineering / Manufacturing Inc. has been designing and manufacturing great pasteurizers for over four decades.

For more information on tunnel and batch pasteurization contact PRO Engineering / Manufacturing, Inc. at [email protected] or call (414) 362-1500 and ask for Ed Michalski, CEO.

Partner with a PRO!… PRO Engineering / Manufacturing Inc.

Internal Resources:

Is Tunnel Pasteurization Best for Craft Beers?

In the food and beverage industry, pasteurization is a crucial part of producing many different goods. That includes craft beer and other fermented drinks. It is important because it destroys pathogens and increases the product’s shelf-life. It makes it safer and cheaper for the consumer. Pasteurization of craft beers is essential for its production.

There are different ways to pasteurize a beverage. It usually depends on the size of the batch and the method that the brewer feels more comfortable with.

These methods can vary in cost, efficiency, and practicality. One of the most common and practical methods is tunnel pasteurization.

Microbreweries and any other types of production can find tunnel pasteurization extremely useful. This article will provide more information about this type of pasteurization. There will be an explanation of its benefits, how it works, and where to find the best batch pasteurizers.

Over the years, more microbreweries and craft beer producers have adopted tunnel pasteurization. This pasteurization process is ideal for mass production and consumption of beer. It is also good for other fermented drinks as well.

Tunnel pasteurization increases the product’s shelf life. It allows producers to ship it to other cities and states instead of limiting it to one specific region. 

Benefits of Tunnel Pasteurization

Tunnel Pasteurization destroys pathogens and microorganisms. These are usually found in the liquid and the package of the product. 

Also, by pasteurizing the liquid inside its package, the brewer can stimulate yeast growth. When combined with sugar and water, yeast causes fermentation. Fermentation then results in alcohol and that sizzling characteristic of fermented beverages. 

By inducing yeast growth inside the package, there will be a second fermentation. This provides more complex flavors to the liquid inside. 

For the pasteurization of craft beers, this method can be helpful to increase shelf life. As mentioned before, this is beneficial for shipping products to other regions and states, expanding sales. 

Another benefit of tunnel pasteurization is that it does not need a lot of work. Flash pasteurization, in comparison, is much more demanding. It has a larger number of processes involved in the pasteurization of the product. With tunnel pasteurization, the procedures are much shorter and much more efficient. 

Tunnel Pasteurization of Craft Beers

Tunnel Pasteurization can seem costly at first for a microbrewery. But its benefits, practicality, and sale results make it worth the money spent. 

When purchasing a tunnel pasteurizer, one should consider different aspects of its production. The size, shape, and material of the bottles affect the conditions for pasteurization.

They affect how the heat interacts with the liquid. Larger containers, holding more liquid, heat up slowly. 

If the liquid temperature inside the bottle gets too high during pasteurization, the flavors can change. So can the foam of the beer. If it does not get hot enough, pathogen extermination may not be 100% effective. 

Tunnel pasteurization is also not recommended for pasteurizing kegs. It is the same for other large beer containers. Because of their size, these packages interfere with the heating and cooling of the beer inside. It then slows down the pasteurization process and makes it less effective. 

For keg beers, they recommend using the flash pasteurization method. Here, the liquid gets fermented separately from the package. 

Types of Tunnel Pasteurizers

At PRO Engineering / Manufacturing Inc., there are two types of tunnel pasteurizers, depending on the size of the brewery.

The Large Series of tunnel pasteurizers is one of today’s most cost-effective lines to operate. It has reduced energy, water, and maintenance costs and low downtime. 

The SlimLine family of tunnel pasteurizers is a much smaller series. It can accommodate microbreweries that do not have a lot of production space. It has most of the features present in the Large Series, but with a cheaper price, smaller size, and lower footprint. 

Tunnel Pasteurization for Craft Beers Conclusions

Pasteurization is an essential part of beverage production, and craft beers are no exception. With tunnel pasteurization, breweries can find an effective way of killing pathogens and microorganisms. They do it with the beer and the package in a practical, safe, cheap manner.

The benefits of tunnel pasteurization are many. It is profitable for microbreweries and craft beer producers to invest in tunnel pasteurizers, as it expands sales. 

At PRO Engineering/Manufacturing Inc., brewers can find top-tier tunnel pasteurizers. If you are interested, you can request more information by visiting our contact page. Explore our website for many other products and tips on brewing, fermentation, and pasteurization of beverages.

What Is Tunnel Pasteurization?

Tunnel pasteurization is one of the most used and famous methods of pasteurizing beer and other beverages today.

The other most famous one is flash pasteurization. Flash pasteurization pasteurizes only the product.

Tunnel pasteurization pasteurizes both the package and the product. This makes it more practical when fighting pathogens found in beer bottles and cans. It makes the product safer for consumption.

Tunnel pasteurization works by taking filled bottles and cans of beer and running them through a tunnel. It is a chamber made of stainless steel. Inside it, the product and its package pass through 3 to 12 different temperature zones.

First, they are exposed to progressively higher temperatures, sprayed with hot water. These temperatures then stabilize for a while in the process called pasteurization.

With large tunnel pasteurizers, the liquid inside the can or bottle can reach up to 165 °F. Bigger brewing companies usually use these.

After being held at its greatest heat for a while, cold water is sprayed around the package. The temperature around the cans and bottles starts to drop and become cooler. Then, it reaches the desired temperature for the beer to be stored.

Learn More About Pasteurizing!

If you’d like to learn more about pasteurization in general, pasteurizing unique sodas, or the equipment involved, we’d love to help!

Feel free to contact us with any questions or concerns you might have, and we’ll do our best to help you. We want you to feel confident in your understanding of this vital process and how you can make it work for you!

For more information on tunnel and batch pasteurization contact PRO Engineering/Manufacturing, Inc. at [email protected] or call (414) 362-1500 and ask for Ed Michalski, CEO.   

Edward A. Michalski Bio  
Ed Michalski started his career in the beverage industry by designing stainless steel, higher flow, spray headers for Pabst Brewing. Along with the header design, he also developed a process to produce the new headers.   Ed, along with his brother David, formed PRO Engineering/Manufacturing, Inc. 

Based on what they learned by re-designing and refurbishing other manufacturers’ pasteurizers, Ed and PRO started to offer the pasteurizer marketplace superior new pasteurizers.  

PRO Engineering/Manufacturing has been designing and manufacturing tunnel pasteurizers and batch pasteurizers for over four decades.  

ABOUT US:
PRO Engineering and Manufacturing was established in 1977 by Ed and Dave Michalski as a steel fabrication shop. For more than 40 years, PRO Engineering and Manufacturing, Inc. has been delivering solutions for beverage product shelf stability and consumption safety. As leading innovators in post-fill pasteurization, our skilled team offers the best in high-quality pasteurization equipment.

CONTACT US:
Phone: 414-362-1500 | Email: [email protected]

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Location: 11175 W Heather Ave, Milwaukee, WI 53224, USA

Heating and Cooling Options for Tunnel Pasteurizers

Packaged beverages can be processed to improve preservation and shelf-life; this is called pasteurization (1). We will examine the variation called Thermal Pasteurization. It occurs by heating and cooling the filled product packages according to a thermal cycle. From the thermal point of view, the tunnel is divided into 1) a pre-heating area, 2) a heat treatment area, and 3) a cooling area where the product is brought back to ambient temperature (1,2).

The cans or bottles travel through these areas progressively where water is sprayed on them to modify their temperature; those thermal changes produce a reduction of microorganisms in the beer minimizing the effect on physical stability and flavor while maximizing biological stability (microorganisms) (3). Also, any leftover yeast is deactivated. Filtered beer typically has a target P.U. range of 12 +/-2 for proper pasteurization (1 P.U. is added to the product when exposed to 60°C (140°F) for one minute) (4).

Water spray systems, including spray patterns, water volumes, and distribution systems, depend on the pasteurizer manufacturer (3). There are several options for elevating the product’s temperature to the adequate pasteurization temperature, usually using low and high-pressure steam or high-temperature water in either direct or indirect heating (5). The principles and effects of thermal preservation treatments such as this one are well established (6), and publications are widely available to delve deeper into the topic, such as the book Handbook of Brewing by Stewart & Priest (ed. 2017)(7).

The temperature at which water reaches its boiling point is a function of pressure; at atmospheric pressure, steam is created initially at 100°C (212° F). Interestingly, steam at 100°C (212° F) has a substantially higher heat capacity than the same amount of water at the same temperature.

This happens because when steam condenses on the surface of a cooler can or bottle, the latent heat of condensation is released on the surface as the steam turns from the higher energy gaseous state to the lower energy liquid state (8); producing a rapid rise in the surface temperature with little sensible heat change in the heating medium. However, high-temperature water can also be applied to beer containers by spraying or by deluging with cascading sheets or by immersion (7).

The heating of the water needed for spraying on the containers can occur by different means. Heat exchangers are often used. These exchangers contain fluids depending on the requirements, such as saturated steam, heated water, and others(9). The heat needed to pasteurize can be obtained by different options such as direct fire, gas-fired boilers, and electrically heated boilers.

In a low-pressure boiler, the pressure does not surpass 15psi while the temperature stays below 121°C (250° F). This type of boiler does not need constant monitoring. On the contrary, high-pressure boilers heat steam more than 15psi, and temperatures exceed 121°C (250° F). High-pressure boilers must have a boiler operator on staff to constantly monitor valves, switches, safety devices, or leaks.

Some manufacturers recently have adopted a centralized heating system (2). This system involves a single heat exchanger for all areas subjected to temperature control, providing heating a quantity of water maintained at a sufficient temperature for mixing with the process water of various areas depending on each area’s needed temperature. In this way, thermal energy is distributed by masses of hot water added in the different areas where a rise of temperature is required (Panella & Pasoli, 2000).

Cooling is required to lower the product temperature in the third area of a tunnel pasteurizer, a temperature that is acceptable for labelling, packing, and storing. The cooling is usually done by direct injection of a cooling medium; this medium could be potable water obtained from a municipal water system or private well. Also, the cooling water could be recycled from the process and cooled mechanically in a cooling tower or water cooler (5).

Glycol is a cooling liquid typically used in refrigeration systems; the addition of glycol changes the freezing point of water from 0°C (32° F) to -15°C (-60° F). Water/glycol mixtures have also been used in high-temperature short-time pasteurizers.

The brewing of beer requires large amounts of thermal and electrical energy; breweries nowadays use 7.5–11.5 kWhel and 16.7–33.3 kWhth per hectoliter of beer (10), while the annual output of medium to large breweries could be up to one million hectoliters. In the brewing industry, 80% of this energy is for process heating(11).

Early pasteurizer manufacturers made little attempts to conserve or reuse the energy used in heating and cooling the product during the tunnel pasteurization process. Later, initial attempts to conserve resources and energy resulted in “regeneration” of water cooling/heating (12).

This means that the spray water is cooled as it raises the cool product’s temperature before being pumped to the “regenerative pair,” the zone where the cooling spray is heated up as it cools the hot product pumped to the cold zone. This results in a heat transfer system called “regeneration” (9). Tunnel pasteurizers can potentially have several regenerative pairs.

Pinguli et al. (2018) conducted research to identify areas of opportunity for breweries’ energy efficiency. They found out that the areas of action that could produce immediate results include condensate return systems, recycling of cooling water, effective control of boiler efficiencies, developments in electrical power consumption and water and heat recovery in pasteurizers (13). This is important since having high quality manufactured tunnel pasteurizers will provide more energy efficiency. Furthermore, there are also attempts to implement solar energy for heating needed in the brewing of beer.

ABOUT US:
PRO Engineering and Manufacturing was established in 1977 by Ed and Dave Michalski as a steel fabrication shop. For more than 40 years, PRO Engineering and Manufacturing, Inc. has been delivering solutions for beverage product shelf stability and consumption safety. As leading innovators in post-fill pasteurization, our skilled team offers the best in high-quality pasteurization equipment.

CONTACT US:
Phone: 414-362-1500 | Email: [email protected]



References:

1. Bhuvaneswari E, Anandharamakrishnan C. Heat transfer analysis of pasteurization of bottled beer in a tunnel pasteurizer using computational fluid dynamics. Innovative Food Science & Emerging Technologies. 2014 Jun 1;23:156–63.

2. Herold JL, Nekola WJ, Wehmiller FW. Process of pasteurizing liquids in containers. US2282187A, 1942. Available from: https://patents.google.com/patent/US2282187A/en

3. Richmond DW, Clyne CW, Holben TM. Pasteurization process [Internet]. US4693902A, 1987. Available from: https://patents.google.com/patent/US4693902A/en

4. Broderick HM. The Practical brewer. A manual for the brewing industry. 1977;

5. Becker KW, Jr LGF, Kropp L, Straka RB. Pasteurization method [Internet]. US4490401A, 1984. Available from: https://patents.google.com/patent/US4490401A/en

6. Stumbo CR. Thermobacteriology in food processing. Elsevier; 2013.

7. Stewart GG, Russell I, Anstruther A. Handbook of Brewing. CRC Press; 2017. 799 p.

8. Purnell G, James C. 8 – Advances in food surface pasteurisation by thermal methods. In: Demirci A, Ngadi MO, editors. Microbial Decontamination in the Food Industry [Internet]. Woodhead Publishing; 2012 [cited 2020 Dec 30]. p. 241–73. (Woodhead Publishing Series in Food Science, Technology and Nutrition).

9. Panella G, Pasoli G. System for controlling the pasteurization heat treatment, in particular of packaged food products, in tunnel-type pasteurizers [Internet]. US6142065A, 2000 [cited 2020 Dec 29].

10. Mauthner F, Hubmann M, Brunner C, Fink C. Manufacture of Malt and Beer with Low Temperature Solar Process Heat. Energy Procedia. 2014 Jan 1;48:1188–93.

11. Lauterbach C, Schmitt B, Vajen K, Jordan U. Solar Process Heat in Breweries-Potential and Barriers of a New Application Area. Renew Energy. 2009;645–7.

12. Adam F. Apparatus for pasteurizing and cooling food products [Internet]. US9943093B2, 2018 Available from: https://patents.google.com/patent/US9943093B2/en

13. Pinguli L, Malollari I, Lici L, Llupa J. Efficient Use of Energy An Important Approach In Minimizing Environment and Operational Costs in Albanian Breweries.

Tunnel Pasteurization Process… History to Today

Pasteurization was developed by Louis Pasteur around 1864 and has been used in the beer industry since the nineteenth century. It refers to the reduction of microorganisms in beer or other foods by heating to a regulated temperature for a specific time in order to minimize the effect on physical stability and flavor while maximizing biological stability (1). Various organisms in beer are not pathological but affect the taste of beer (2). Draft beer is kept refrigerated and usually consumed in a short period of time, however, can and bottle beer is pasteurized for a long shelflife (1,3,4).

The shelf-life of beer has become a critical issue since it is one of the most consumed fermented beverages in the world (5). Beer’s shelf-life is determined by several factors including its microbiological, foam, colloidal, color, and flavor stabilities (6). Several months are possible if common contaminants are inactivated (7,8). This requires a pasteurization process at a time temperature of around 60°C (140°F) for about 20 minutes as stated in the book “Brewing: Science and Practice” by Briggs, Boulton, Brookes, & Stevens (9). Heat treatment of beer is currently done by flash pasteurization, batch pasteurization, or by tunnel pasteurization in the form of bottles and cans already sealed (10). Tunnel pasteurizers are an important procedure in the brewery packaging line (11).

Tunnel pasteurization occurs by traveling the cans or bottles through a tunnel that consists of progressively higher temperature zones, holding zones, and progressively cooler zones (12). Tunnel pasteurizers comprise a long, enclosed chamber, typically 15 to 30m, in which water sprayed onto the packages controls the temperature; the packages are moved through by a conveyor in the tunnel and is divided into 3 to 12 spray zones (13). The zones are divided into a heating zone where the temperature is progressively increased; pasteurization zone, where the product reaches the desired temperature; and cooling zone(s), where the packages are cooled to reach the desired beer out temperature (BOT).

The system includes a shell, tube heat exchangers, regeneration, and steam water heating. The water running off the packages falls into reservoirs and is recycled to the sprays. Tunnel pasteurizers use a single or double deck, nevertheless, the single deck conveyor has become more prevalent in the brewing industry in the United States because the lower decks in the double set are more likely to be subject to blockage (1).

Brewers should consider that aspects such as bottle size, material and shape influence the specific pasteurizing conditions, such as residence time within the tunnel, to achieve appropriate results (13). If pasteurization reaches a beer temperature too high from the desired level, flavors called “pasteurization tastes” may develop in the beer, along with alterations in the foam formation (15).

Tunnel pasteurizer manufacturers incorporated the term Pasteurization Unit (P.U.) to monitor the process, in order to measure the “lethal effect” of the heat on the microorganisms in the beer, tea, or other infused beverages (1). It is defined that 1 P.U. is added to the product when exposed to 60°C (140°F) for one minute. Lethality (P.U per minute) is a rate term exponential
with temperature (16). Lethality is significant only when the temperature reaches around 57°C (135°F), even when P.U accumulation starts at 49°C (120°F). The organisms which cause the most trouble in the brewing industry are lactobacillus, pedioococcus, and wild yeast, causing
turbidity and poor taste in beer (13), or, additionally, in the case of yeast, continued production of carbon dioxide leading to bursting bottles or undesired can expansion.

The theory of transfer of heat from the water spray to the beer in the can or bottle is that the film resistance to transfer is greatest at the inside wall of the container. The mixing within the container occurs via thermal conduction and convection currents generated while beer is heated
and circulated (1). The motion of circulation across the heat transfer surfaces reduced the internal surface film resistance and inclines to cause equilibrium in the beer temperature. The “cold spot” in the can or bottle is in the center of the bottom because is the last point to be in equilibrium
temperature. To ensure complete pasteurization of beer, the “cold spot” should reach the 60°C (140°F) which is the lowest possible peak temperature in order to avoid overheating the rest of the package since temperature gets higher going from the “cold spot” to the top of the can or
bottle.

Beverage makers also should be aware that different minimum P.U.s have
been considered as the requirement for pasteurizing different beverages. Fine filtered beer typically has a target PU range of 12 +/-2 for proper pasteurization, whereas hard cider may have a higher minimum magnitude of pasteurization starting at 20 to 25 Pus. Once we start talking about non-alcoholic beverages with natural sugars added we often change how
we talk about pasteurization and we look to hold the product at a temperature for a certain time, maybe 165F for 10 minutes as P.U. levels alone will not be enough for proper pasteurization. International brewing groups refer to the rate of under-pasteurized packages as one per 10,000
packages, being desired non-detectable or “less than 1” CFU/ml of aerobic and anaerobic bacterial testing, yeast, and molds.

Traditionally, tunnel pasteurizers use spray densities as low as 3.4 gals/min./ft. of tunnel surface area and use spray heads aligned in a straight line running the length of the tunnel. However, in poorly designed tunnel pasteurizers, measurements have shown a variance of water applied to the containers across the width of the tunnel, resulting in non-uniform heating or cooling of the beer. Modeling of the pasteurization tunnel has been demonstrated to be useful to predict the operation status of the process to make changes in the design, operation, or optimization (17–20).

There are different references of design, description, features, and capabilities of tunnel pasteurizers in the brewing industry; the publication by the Master Brewers Association of the Americas titled “A comparison of flash and tunnel pasteurization technologies used for brewery packaging applications” written by Duff et al., may be useful for delving deep into the topic. Another reference for more information is the Brewers Association for Small and Independent Craft Brewers where regularly published information on topics related to pasteurization appears.

Figure 1: Temperature of bottled beer during the pasteurization (60 °C) process at different time intervals by Bhuvaneswari & Anandharamakrishnan, 2014.

Figure 2: Example of a Tunnel Pasteurizer by Richmond et al., 1987

References

  1. Richmond DW, Clyne CW, Holben TM. Pasteurization process [Internet]. US4693902A, 1987 [cited 2020 Nov 16]. Available from: https://patents.google.com/patent/US4693902A/en
  2. Reveron IM, Barreiro JA, Sandoval AJ. Thermal Resistance of Saccharomyces cerevisiae in Pilsen Beer. Journal of the Institute of Brewing. 2003;109(2):120–3.
  3. Herold JL, Nekola WJ, Wehmiller FW. Process of pasteurizing liquids in containers [Internet]. US2282187A, 1942 [cited 2020 Nov 17]. Available from: https://patents.google.com/patent/US2282187A/en
  4. Wehmiller FW. Conveying apparatus [Internet]. US2658608A, 1953 [cited 2020 Nov 17]. Available from: https://patents.google.com/patent/US2658608A/en
  5. Takashio M, Shinotsuka K. Preventive Production of Beer against Oxidation—Recent Advances in Brewing Technology. Food Science and Technology International, Tokyo. 1998;4(3):169–77.
  6. Vanderhaegen B, Neven H, Verachtert H, Derdelinckx G. The chemistry of beer aging – a critical review. Food Chemistry. 2006 Apr 1;95(3):357–81.
  7. Priest FG, Stewart GG. Handbook of brewing [Internet]. 2006 [cited 2020 Nov 16]. Available from: https://scholar.google.com/scholar_lookup title=Handbook%20of%20Brewing&author=F.G.%20Priest&publication_year=2006
  8. Jespersen L, Jakobsen M. Specific spoilage organisms in breweries and laboratory media for their detection. International Journal of Food Microbiology. 1996 Nov 1;33(1):139–55.
  9. Briggs DE, Brookes PA, Stevens R, Boulton CA. Brewing: Science and Practice. Elsevier; 900 p.
  10. Buzrul S. A suitable model of microbial survival curves for beer pasteurization. LWT – Food Science and Technology. 2007 Oct 1;40(8):1330–6.
  11. Bhuvaneswari E, Anandharamakrishnan C. Heat transfer analysis of pasteurization of bottled beer in a tunnel pasteurizer using computational fluid dynamics. Innovative Food Science & Emerging Technologies. 2014 Jun 1;23:156–63.
  12. Engelman MS, Sani RL. Finite-Element Simulation of an in-Package Pasteurization Process. Numerical Heat Transfer. 1983 Jan 1;6(1):41–54.
  13. Dilay E, Vargas JVC, Amico SC, Ordonez JC. Modeling, simulation and optimization of a beer pasteurization tunnel. Journal of Food Engineering. 2006 Dec 1;77(3):500–13.
  14. Clyne CW, Woolever GL, Teng J, Naji H. Pasteurization monitoring process. Google Patents; 1989.
  15. Zufall C, Wackerbauer K. The biological impact of flash pasteurization over a wide temperature interval. Journal of the Institute of Brewing. 2000;106(3):163–168.
  16. Broderick HM. The Practical brewer. A manual for the brewing industry. 1977;
  17. Brandon H, Gardner R, Huling J, Staack G. Time-dependent modeling of in-package pasteurization. Technical quarterly-Master Brewers Association of the Americas (USA). 1984;
  18. Horn CS, Franke M, Blakemore FB, Stannek W. Modelling and simulation of pasteurization and staling effects during tunnel pasteurization of bottled beer. Food and Bioproducts Processing. 1997;75(1):23–33.
  19. Kumar A, Bhattacharya M. Transient temperature and velocity profiles in a canned nonNewtonian liquid food during sterilization in a still-cook retort. International Journal of Heat and Mass Transfer. 1991;34(4–5):1083–1096.
  20. Beck JC, Watkins AP. The droplet number moments approach to spray modeling: The development of heat and mass transfer sub-models. International journal of heat and fluid flow. 2003;24(2):242–259.

ABOUT US:
PRO Engineering and Manufacturing was established in 1977 by Ed and Dave Michalski as a steel fabrication shop. For more than 40 years, PRO Engineering and Manufacturing, Inc. has been delivering solutions for beverage product shelf stability and consumption safety. As leading innovators in post-fill pasteurization, our skilled team offers the best in high-quality pasteurization equipment.

CONTACT US:
Phone: 414-362-1500 | Email: [email protected]

Tunnel Pasteurization Process for BrewMasters & Their Beer

Pasteurization is an important unit operation in beer processing that inactivates the spoilage microorganisms present in beer thereby extending its shelf life. Pasteurization is the reduction of microorganisms by heating to a limited temperature and holding at that temperature such that there will be minimum effect on physical stability and flavor and a maximum extension of biological stability.   

When the effect of pasteurization on the microbiological and sensory quality of white grape juice and wine was investigated by a UC Davis team, heat treatment of less than 3 Pasteurization Units (PUs = minutes at 60°C or equivalent) was sufficient to reduce 106 cells/mL of Saccharomyces cerevisiae and Hansenula anomala added to Chenin blanc juice to an undetectable level (1). 

Most brewers in the world pasteurize beer, including many craft breweries. The organisms which cause the most difficulty in the brewing industry today are lactobacillus, pediococcus and wild yeast. These are not pathogenic organisms but can cause turbidity and poor taste in beer.  

In order to insure complete pasteurization of beer, the temperature of the beer at the so-called “cold spot”, which is 1/4″ from the bottom of the center of the can or bottle, must reach at least 140° F. for a period of time to produce a specified number of pasteurization units (P.U.). It also is desired to pasteurize at the lowest possible peak cold spot temperature (above 140° F.) to avoid overheating the rest of the package contents, because the temperature of the package gets higher as one goes from the cold spot to the top of the package. 

Today’s brewery has several options when making decisions about long–term stability of its beers. 

Sterile filtration can fail, and beer can get infected at packaging.  Flash pasteurization has the same limitation as sterile filtration in that pristine beer can get infected immediately after it exits either the sterile filter or flash pasteurizer, so greater care is required, and more hygienic engineering design integrated. A ‘sterile fill-capable’ filler can cost at least $1.5 million, yet a “normal” beer filler (not aseptically-certified) at the same throughput can cost as little as $225,000.  

Since the USA has no larger-scale packaging machinery fabricators, the European standard testing A-3 is the baseline aseptic-capability certification testing. The growth of canned beer has led to a variety of small, linear canning systems which are clearly microbiological traps for beer being packaged. 

But when a company invests in a tunnel pasteurizer designed and engineered to suit the purpose by PRO Engineering, the process is on the packaged beer inside the can or bottle. 

Many craft beers cannot be sterile filtered, and those that are may experience some degree of flavor scalping and stripping as the beer is pushed through 0.22 micron to 0.45 micron polymeric or ceramic filtration media. 

It is true that pasteurization at least temporarily changes beer flavor, but in work I’ve done, the best flavor panel in the world could not discern Control vs Pasteurized after 3-7 days had passed when controls and tests were stored at ambient temperature (for mainstream-style lager beers). When you briefly heat beer, you increase the rate of oxidation during that period, but after 3-7 days, the level of oxidation effects are the same in unpasteurized beer (2). 

Is it true that many, many small breweries have no sterile filtration nor pasteurization of any kind? Of course that is true. And some of these beers travel quite far before they are consumed, often having long storage times, too. Loads of people are happy to drive without seat belts while also texting on their mobile phones. Despite understanding the risks, loads of people enjoy smoking cigarettes and some people happily let their children enjoy swimming in the pool unsupervised.  

A pasteurizer represents an investment and a commitment to sustained quality and security as much as putting on that seatbelt and choosing to not text while driving. It’s true that a number of beer aficionados look down on the process, express that only mega-breweries use it, that’s it’s wrong for craft beers. And there certainly are brewers who came into professional brewing from backgrounds which had no tunnel pasteurizers in their past, and use their platforms as brewers in craft breweries to reinforce the opinions that pasteurized beer has had some of it specialness removed.  

Every Master Brewer I know who pasteurizes beer sleeps better because it is inevitable that sometimes something will slip through, from a slight tear on a filter pad, for example, or a chance passage through an imperfectly cleaned and sanitized hose or coupling or union. And if not denatured, it could change flavor in the package for worse. 

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We all know how draught beer can sometimes disappoint us, and we know that if lines aren’t cleaned correctly and with the right frequency, then the beer itself changes flavor. That is a concern that extends to flash-pasteurized or sterile-filtered beer, also: how clean is everything touching the beer after it has gone through the particular process? 

In the engineered PRO pasteurizer serving for beer pasteurization, the sequence consists of a heat-up phase producing a uniform rise in temperature, a phase of heating at a temperature level and a cooling down phase, the heating and cooling of the container holding the liquid achieved by a spray of water from non-clogging spray heads whose temperature is a function of the zone in question. The conditions under which the pasteurization must take place are a function of the product to be treated, the geographical distribution point, the pollution of the base product and requirements of the law.  

For a given beer, the operation of pasteurization should require, for example: 

–Exceeding a temperature threshold for a definite time, which can be very short, 

–Standing at a temperature for a minimum time, 

–The acquisition by the product of a certain number of “pasteurization units” or PU’s, 

Remember that a PU is defined as the effect of pasteurization obtained, for example, in beer by holding for one minute at 60° C. (140° F). The pasteurization effect is by definition the biological destruction produced by holding at a predetermined temperature, which is a function of the product, for a certain time. To this end, in various zones of a PRO pasteurization tunnel, various temperatures are adjusted with which the temperature of the products can be slowly increased and possibly subsequently slowly reduced again. 

A beer with low counts of anaerobes and aerobes may exit a pasteurizer with zero counts with 8 PU, but another batch with higher counts may need 12 or 15 PU. Beers shipping internationally are best given higher pasteurization, ie 20 PU. The team at PRO can discuss how to evaluate pasteurization targets, PRO also offers innovative batch pasteurizers models for smaller runs and research operation to validate PU targets, 

Authored by Jaime Jurado

Past President-MBAA(Master Brewers Association of the Americas)
https://www.linkedin.com/in/jaimejurado/
https://independent.academia.edu/JaimeJurado

Article References:
https://doi.org/10.1111/j.1745-4549.1991.tb00151.x
https://doi.org/10.1111/j.1365-2621.1994.tb02061.x 

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PRO Engineering and Manufacturing was established in 1977 by Ed and Dave Michalski as a steel fabrication shop. For more than 40 years, PRO Engineering and Manufacturing, Inc. has been delivering solutions for beverage product shelf stability and consumption safety. As leading innovators in post-fill pasteurization, our skilled team offers the best in high-quality pasteurization equipment.

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ABOUT US

PRO Engineering/Manufacturing, Inc. was established in 1977 by Ed and Dave Michalski as a steel fabrication shop. From this modest beginning, complete machine fabrication capabilities were quickly added followed by the installation of our own in-house engineering and design group.

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