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The Art of Balancing Flavor and Safety: Tunnel and Batch Pasteurization Techniques in Craft Brewing

PRO Engineering / Manufacturing Inc.

Introduction

  • The delicate balance between flavor perfection and safety assurance in craft brewing
  • Importance of mastering tunnel and batch pasteurization techniques
  • Overview of how tunnel and batch pasteurization methods ensure both safety and flavor in craft brewing

Understanding Tunnel Pasteurization Process

  • Description of tunnel pasteurization process
  • Utilization of tunnel pasteurization in craft brewing
  • Importance of precise temperature control and gradual heating and cooling
  • Preservation of flavor while ensuring safety through tunnel pasteurization

Benefits of Tunnel Pasteurization in Brewing

  • Extending shelf life and ensuring safety of craft beers
  • Maintaining flavor and quality of beverages
  • Uniformity in the pasteurization process
  • Preservation of carbonation levels and traditional characteristics of beer

Tunnel Pasteurization vs. Batch-based Pasteurization

  • Differences between tunnel and batch pasteurization techniques
  • Suitability of tunnel pasteurization for high-volume production
  • Customization options and control in batch pasteurization
  • Balancing safety and flexibility in pasteurization methods

How Tunnel Pasteurization is Implemented in Craft Breweries

  • Process of implementing tunnel pasteurization in craft breweries
  • Use of hot water showers and precise temperature control
  • Preservation of flavor and quality characteristics during pasteurization
  • Benefits of tunnel pasteurization for craft brewers

Safety Measures in Tunnel Pasteurization for Craft Brewing

  • Importance of safety considerations in tunnel pasteurization
  • Key safety indicators and temperature control measures
  • Comprehensive measures for ensuring safety of craft beer products
  • Consumer confidence and industry standards in craft brewing safety

Flavor Profile Enhancement via Pasteurization

  • Role of pasteurization in enhancing flavor and stability of craft beers
  • Balancing safety standards and flavor preservation
  • Elimination of beer-souring pathogens while maintaining flavor
  • Premium product creation through flavor profile enhancement

Quality Control and Best Practices

  • Importance of quality control protocols in tunnel pasteurization
  • Temperature monitoring and flow adjustment for consistent results
  • Regular equipment calibration and testing post-pasteurization
  • Ensuring safety and quality of craft beer products through rigorous quality control

Best Practices for Craft Beer Pasteurization

  • Utilization of best pathogenic practices in craft beer pasteurization
  • Overview of flash pasteurization and tunnel pasteurization techniques
  • Emphasis on careful temperature control and preservation of taste
  • Advantages of tunnel pasteurization for maintaining safety and quality

Conclusion

  • Recap of the benefits of tunnel and batch pasteurization techniques
  • Encouragement for craft brewers to implement pasteurization for extended shelf life and quality maintenance
  • Importance of balancing safety and flavor in craft brewing
  • Invitation to take brewing to the next level with tunnel and batch pasteurization techniques

Introduction

If you have ever found yourself walking a tightrope between flavor perfection and safety assurance in the production process of craft brewing, mastering tunnel and batch pasteurization techniques is just the northern star for your compass. In the complex and intricate world of beer production, the ability to safely guarantee the product for a prolonged shelf life without compromising its sensory profile is the dependent and independent variables that the tunnel and batch pasteurization methods draw their experimental design from.

Untying the knot behind the secrets of tunnel and batch pasteurization is the key to unlocking the potential to create brews that not only satiate taste buds but outlive human generations.

Understanding Tunnel Pasteurization Process

Tunnel pasteurization involves the careful tandem processes that ensure products are subjected to heating and cooling progressive processes to eliminate harmful bacteria and still ensure quality. The craft brewery method utilizes tunnel pasteurization to protect their integrity and still meet the standards.

Constant showers of hot water over sealed cans or bottles perfectly reach 140 degrees Fahrenheit and precisely eliminate the bacteria. As the beverages move over the multiple zones within the tunnel, they are appropriately pasteurized to maintain microorganism safety. The peak temperatures are held on for some time to ensure that microbes are entirely inactivated.

The high temperatures conditions within the chamber are critical to eliminating the microbes. Additionally, the warm conditions under which the beverages are conducted under the control of the heat levels ensures that craft breweries use the tunnel pasteurization process to ensure that they provide safe products to consumers.

Afterward, the temperatures are reduced to that of the room and gradual cooling is also important to ensure that the quality of the beverages is maintained. In maintaining the cooling conditions, tastes are retained in ensuring that the quality of the beverages is observed. In summary, tunnel pasteurization is crucial as it ensures a balance of safety and flavor.

Benefits of Tunnel Pasteurization in Brewing

Having a clear overview of the process is essential to further provide information regarding the benefits of tunnel pasteurization in brewing. Craft brewers utilize tunnel pasteurization in extending the shelf life of their beers through eliminating the microorganisms that may render the beverages harmful hence safe to sip.

A critical part of tunnel pasteurization for the craft beer industry, it maintains the tastes of the beverages while keeping quality. One particular significance in tunnel pasteurization is the uniformity of one process to the other.

Craft brewers can use different types of containers ranging from cans and bottles among others and in this way, tunnel pasteurization maintains the beverages’ carbonation levels. Tunnel pasteurization allows craft breweries to remain in the industry while meeting the regulations from the authoritative consumers in the industry.

Tunnel Pasteurization vs. Batch-based Pasteurization

The choice to utilize tunnel or batch pasteurization techniques in craft brewing is determined by the brewer’s scale and customization preferences. Tunnel pasteurization refers to the use of tunnel pasteurizers to gradually heat and cool treated beverage packages. This method is recommended for craft brewers engaged in high-volume production because it ensures that the beverage is heated to the proper temperature while cooling at the same rate.

It enables the craft brewer to pasteurize beer in varying quantities and achieve consistent results over more substantial quantities. Conversely, batch pasteurization refers to treating a beverage in a given quantity, batch, or lot.

This method may be more beneficial for craft brewers who seek complete control over the pasteurization process. It also allows the craft brewer to customize the production process and produce beer in limited quantity at a time.

Both procedures are beneficial in ensuring that hazardous microorganisms are eliminated from the beer, while tunnel pasteurization also increases product shelf life and preserves the beer’s flavor. Batch pasteurization, on the contrary, allows the producer to make minor adjustments to the product.

However, both pasteurization methods are effective and reliable because of the hostile conditions which inhibit the survival and growth of hazardous microorganisms. Craft brewers need to realize the benefits of both tunnel and batch pasteurization methods, which include product flavor preservation and maintaining safety standards.

How Tunnel Pasteurization is Implemented in Craft Breweries

Craft brewers implement tunnel pasteurization by passing packaged beverages through a tunnel-like enclosure for heat treatment. Craft brewers use tunnel pasteurization to increase product shelf life and ensure safety. The process may involve hot water showers above the sealed cans or bottles to eliminate hazardous microorganisms.

Due to the fact that tunnel pasteurization is not restricted to a single type of container, it is perfectly suitable for craft brewing. In addition, due to the slow cooking and cooling of the products in the tunnel, the quality and flavor characteristics of the beer are preserved.

One of the key advantages of tunnel pasteurization for craft brewing is the possibility to ensure an acceptable shelf life for the products while preserving their traditional characteristics. The implementation of tunnel pasteurization requires strict controls over the temperature regime in order to be effective.

For craft brewing, tunnel pasteurization allows for ensuring safety, acceptable shelf life, and consumer confidence in the products offered. Overall, tunnel pasteurization is a very effective tool for craft brewing since it offers a reliable method to ensure reasonable safety and quality simultaneously.

Safety Measures in Tunnel Pasteurization for Craft Brewing

Transition to implementing tunnel pasteurization in the technological processes of craft brewing, the issue of safety becomes particularly relevant since it provides a field for maintaining quality and consumer confidence in products. The main safety indicator of the tunnel pasteurizer in craft brewing is the temperature of 140 F.

This temperature ensures that the microflora present in craft brewing is practically completely destroyed in tunnel pasteurization. Due to the gradual stages of heating up and cooling in zones through which the product passes, tunnel pasteurization ensures comprehensive measures to ensure the safety of the craft beer.

A key factor of tunnel pasteurization is the control of the temperature regime since due to precise heating and cooling, it is possible to maintain the quality and uniformity of the production batches during the process of renewal. Proper calibration and setup of pasteurization equipment are critical for post-packaging sanitation.

This process not only ensures that the product is safe for consumption, but it also extends the shelf life of craft beers. Craft breweries should follow safety measures to the letter, and using advanced temperature control techniques produces products that are not only safe but also acceptable in the industry and to the consumer.

Flavor Profile Enhancement via Pasteurization

Pasteurization is an important process in craft brewing that ensures the beer is offered in the market safe for consumption and promotes its flavor. Therefore, with proper pasteurization techniques, the quality and stability of the beer are easily achieved, with the flavor maintained. Balancing safety standards and flavor is much emphasized, allowing preservations that extend its shelf life without tasting like their flavor.

The brewing and restoration process eliminates any beer-souring pathogens while ensuring the flavor is retained. Consistent experience of flavor is enhanced when the flavor is maintained through pasteurization, hence enabling a premium product in the industry. With mastery of pasteurization, the craft brewery product becomes sellable and meets the industry’s health regulatory requirements. As such, through tunnel and batch pasteurization, craft brewers flavor profile their beer and produce safety products in the required standards.

Quality Control and Best Practices

In tunnel pasteurization, quality control protocols involve temperature monitoring, which is paramount to securing the safety and quality of craft beer products. Strict adherence to precise temperatures enables brewers to eliminate harmful bacteria pathogens, while the beer’s quality and taste remain uncompromised. Flow monitoring and adjustment also assist in maintaining even heat distribution throughout the beer and ensuring all parts reach optimal pasteurization.

Regular equipment calibration is vital to verifying equipment performance and product safety. It maintains the equipment and ensures temperature control accuracy, which is essential for the pasteurization’s success and product overall safety. Testing samples post-pasteurization, part of quality assurance protocols, is fundamental in assuring a successful pasteurization process and product.

Quality control in tunnel pasteurization is crucial to ensuring the safety and quality of craft beer products. To guarantee these objectives, producers must follow the guidelines outlined in this paper and observe unperturbed monitoring throughout the pasteurization process. Quality control favors craft beer production by maintaining the beer’s quality and safety to industry levels. Craft brewers have the responsibility to ensure the quality control of their products so that their beers remain delicious as they produce safe beers.

Best Practices for Craft Beer Pasteurization

Craft brewers may employ the best pathogenic practices to strike a balance between safety and brewing processes while producing delicious beer to meet the industry’s safety industrial standards. In conclusion, in the context of beer pasteurization, commercial craft brewers have several options. Flash pasteurization is one of the most common, the essence of which is that the beer is heated in a short time up to a high temperature and then quickly cooled down. It is possible to quickly eliminate harmful pathogens, and the impact on the beer’s taste will be minimal. Whether you are pasteurizing beer in bottles or cans, craft brewers need to monitor temperature carefully.

Pasteurization must be done promptly to ensure microbial death and without destroying the beer’s unique, nuanced taste profiles. Proper calibration of tunnel pasteurization equipment is ideal to ensure that every package gets consistent treatment. Tunnel pasteurization equipment also helps increase shelf life, increase the overall safety of the beer after wrapping, and maintain the proper taste of the beers. Therefore, tunnel pasteurization equipment is advantageous because it covers both packaging and beer, which reduces the risk.

Frequently Asked Questions

What is the tunnel pasteurization process? Tunnel pasteurization is the process where the beverage runs through the chamber like a tunnel and is heated or cooled down at a gradual rate. It contains hot-water showers used in sealed cans or bottles. The beer is kept at 140 degrees Fahrenheit in the tunnel to ensure the safety of the beer. There are different zones that keep the beverage at peak temperatures to kill the beer effectively. The temperatures must be kept low to bring the beer to a room temperature gradually. The process must have a precise temperature control because tunnel pasteurization enables the beverage to have the same taste while protecting the beverage.

What is the difference between flash – pasteurization and tunnel-pasteurization? Craft brewing uses two kinds of pasteurization – flash and tunnel. Flash pasteurization is a rapid heat method that heats beer to 160-161.6°F. It is primarily for beer that is inside kegs; it is fast because microbes are sometimes exposed after it. However, tunnel pasteurization aims to treat the package itself with the product by passing them through a 140°F tunnel with steam or hot water at a temperature of 165°F. It is highly suitable for mass production as it keeps the product at the highest levels of quality and safety. Tunnel pasteurization is favored by craft brewers for maintaining high-quality standards. Flash pasteurization, on the other hand, is less safe as it is faster and may compromise beer safety.

What Is Pasteurization Process in Beer Making? In craft brewing, the process is highly specific and aims at removing unfavorable microorganisms to improve beer’s longevity. Pasteurization allows the product to be stored for more prolonged periods without losing or compromising quality or safety standards. It is crucial for breweries to remove the pathogenic elements in their beers. Flash and tunnel pasteurization are two efficient methods to ensure beer safety and longevity.

What Are the Techniques of Brewing Beer? In brewing beer, crucial techniques are tunnel and batch pasteurization. The former enables to gradually heat and cool the product within a tunnel-like tunnel, while the latter is canon-by-canon sealed cans or bottles in hot water showers. Both techniques help remove pathogens and last longer while preserving taste. Craft brewers have full control over the process to prolong beer shedding and ensure its safety and quality.

Conclusion

Now that you’ve unlocked the secrets of flavor and safety in your craft brewing through tunnel and batch pasteurization, you can suspend your beer for an extended period with minimal flavor loss. Introducing tunnel or batch pasteurization in your brewery will keep your products longer and maintain quality standards, exceeding consumer expectations. Take your brewing game to the next level with tunnel and batch pasteurization!

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.

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What Is the Best Pasteurization Method for Beer and Beverages

If you thought that pasteurization was only for milk, it’s time to think again. Pasteurization is important for beer and other beverages, too!

The reason why this is so important is that pasteurization heats the beverage up to temperatures of at least 145ºF. At those temperatures, bacteria and microbes die, leaving a clean and safe beverage. 

The question is, what is the best pasteurization method for beer & beverages? In this guide, we’ll take a look at a few different methods for the pasteurization of beer & beverages and their benefits. 

Why Pasteurize Your Beer

Before we start examining different beer pasteurization methods for microbreweries or large breweries, let’s talk about why you should pasteurize your beer in the first place. After all, this isn’t a legal requirement. 

When making craft beer, a beverage maker has to decide whether he or she wants to pasteurize their beer or not. Unpasteurized beer is actually safe for human consumption, making this step an added bonus for anyone who does it. 

The reality is, however, many breweries don’t sell their products immediately after production. That means the beer sits in bottles on shelves for a considerable amount of time.

When a brewmaster chooses to pasteurize beer, he ensures that the beer lasts for a longer amount of time. That makes for a higher quality product and helps reduce costs on expired products that can’t be sold. 

Benefits of Pasteurizing Beer

Aside from increasing the shelf life of beer, pasteurizing beer has several other benefits. Let’s take a look at them in a bit more depth. 

Kills Germs

One of the most important reasons for pasteurizing beer is that the process destroys pathogens and bacteria that can grow in beer. That ensures that a company’s packaged beer is safe for drinkers and won’t go bad quickly.

Prevents Yeast Growth

Sometimes, the brewing process leaves yeast residue in the beer. If left unchecked, that yeast can begin to grow wild, altering the flavor and freshness of the beer. 

Pasteurizing stops the growth of that yeast. The result is a beer that tastes better and lasts longer. 

Reduces Refrigeration Needs

Pasteurized beer kegs can last for six to nine months at room temperature. On the other hand, unpasteurized beer will only last for about 45 to 60 days. 

In addition, pasteurized beer can go back in the refrigerator after it’s been opened. You cannot place unpasteurized beer back in the refrigerator after you open it and will have to use it all or throw it away. 

Allows for Greater Expansion

As you might imagine, since pasteurized beer lasts longer, brewers can ship their beer greater distances. They can cut back on the cost of producing more beer and can help eliminate waste in their processes. 

Tunnel Pasteurization vs Batch Pasteurization

Now, there are a few different pasteurization methods out there. Two popular methods are batch pasteurization and tunnel pasteurization. Let’s take a look at each of these methods in a bit more detail.

Batch Pasteurization

Batch pasteurization has long been a popular pasteurization method for beer and milk products alike. With this pasteurization method, the brewer places the beer into a temperature-controlled vat. 

Then, the beer inside the vat gets slowly warmed up to a temperature of at least 145ºF. From there, the beer will sustain its temperature for about half an hour. 

When the time is up, the brewer cools the beer back down and pumps it out of the vat. From there, the beer can be bottled and prepared for sale and shipment. 

Benefits of Batch Pasteurization

Batch pasteurization offers brewers a couple of different benefits:

  • Effective at killing bacteria and pathogens
  • Can be used for kegs of beer rather than bottles and cans
  • Offers consistent pasteurization quality

Thanks to these benefits, this type of pasteurization makes sense for brewers who want to process kegs of beer. The process takes place before the beer is bottled and is relatively fast, making it a convenient pasteurization method.  

Tunnel Pasteurization

Tunnel pasteurization is a process where brewers run cans full of beer through a stainless-steel tunnel. In the tunnel, the machine sprays hot water onto the finished product. 

The tunnel method heats the beer to temperatures of 140ºF and holds it at a set amount of time. Then, the machine moves the beer down the tunnel to a different section where it is cooled down again. 

This method usually works best for cans and bottles rather than for kegs. That’s because the size of the kegs makes it tough for the machine to effectively heat and cool the beer quickly. 

Benefits of Tunnel Pasteurization

Tunnel pasteurization has a few key benefits:

  • Extremely effective at killing harmful bacteria
  • Extremely effective at preventing yeast growth
  • Ideal for brewers with a national/international presence
  • Not work-intensive

Thanks to these perks, it’s becoming a popular pasteurization method for larger-scale craft breweries. 

What Is the Best Pasteurization Method for Beer & Beverages? It Depends

So, what is the best pasteurization method for beer & beverages? The truth is that the answer depends. Both tunnel pasteurization and batch pasteurization have their benefits for breweries. 

What does matter is that you use a pasteurization method at all. By pasteurizing their beer, craft breweries and largescale operations alike can keep their customers safe from harmful diseases.

If you’re in need of a batch pasteurizer or tunnel pasteurizer, we’ve got you covered. Get in touch with PRO Engineering / Manufacturing Inc to place an order today.

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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A Basic Guide to Purchasing and Using Tunnel Pasteurizers

By Edward A. Michalski 

CEO 

PRO Engineering/Manufacturing, Inc. 

Tunnel pasteurizers are efficient and effective machines that are available in numerous sizes. The food and beverage industries use them to kill microbes, stop fermentation and in general, provide shelf stability. 

These machines are subject to significant heat variations, caustic cleaning chemicals, steam, water, huge mechanical stresses and in many applications, broken bottles. 

PRO Engineering/Manufacturing, Inc. has been maintaining, repairing and re-engineering tunnel pasteurizers for over four decades. PRO designs and builds our own tunnel pasteurizers and refurbishes competitor’s machines. 

There are different types of tunnel pasteurizers classified by the mechanism that moves the pasteurized product through the tunnel.  

Walking Beam 

This is an older configuration that employs alternating strips, picking and stepping product forward. Most of these machines are being re-engineered into belt pasteurizers. 

Belt 

This is a newer design that uses stainless steel or plastic mats/belts. The Mid 90’S transition away from walking beam saw the advent of perforated plastic belts, wire mesh belts and hybrid versions. (plastic and metal combinations) 

Carrier 

These are formed carrier channels that are mounted to roller chains on each side. The channels support the product and transfers it through the tunnel. 

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SlimLine Tunnel Pasteurizer 
(Small Tunnel Pasteurizer) 

Next, let’s look at the areas/sections of a tunnel pasteurizer. 

Infeed 

This is the area at the entrance to the machine. It can be problematic if the infeed conveyor does not hand off the bottles/cans to the mat/belt effectively. 

Sump 

The area under the belt that catches the water after it has flowed over the cans/bottles/packages that contain the product being pasteurized. The quality of the bottles can be a factor in the amount of bottle breakage. If breakage occurs, the material can be captured in the sump or continue to move out and drop off from the discharge conveyor. 

Watertight Access Ports 

These openings are watertight ports positioned on the side of the tunnel to give maintenance workers access to the belt and/or the sump for cleaning or service.  

Zones 

The tunnel is divided into multiple zones from the front to the back of the machine. The zones have spray nozzles or drip pans inside them, at the top of each zone. The various zones spray water at different temperatures to warm and cool the product being pasteurized. 

Pasteurization Units 

 Although not a part of the pasteurizer, pasteurization units, are an integral part of operating a pasteurizer correctly. Abbreviated as PUs, pasteurization units are a measure of the amount of time and temperature a food or beverage has been subjected to, in order to kill off microbes and deactivate yeast cells. The pasteurization units are equal to 1 PU when the product is exposed to 60°C (140°F) for one minute Depending on the type of food or beverage, the PUs required for appropriate pasteurization varies.   

Pasteurization Unit Monitor 

A pasteurization unit monitor performs the function of monitoring the PUs (pasteurization units) that the beverage or food has been subjected to during its ride through the pasteurizer. The monitor is a system that consists of hardware and software. The hardware travels on the belt with the product being pasteurized. After the trip is finished, the hardware downloads the measurements of time and temperature to a laptop computer and the PUs are calculated. 

Controls 

PLC-based controls that use an HMI (Human Machine Interface) are standard. The PLC will have numerous programs available to be loaded in it that control the water sprays inside the tunnel. Time and temperature are varied depending on the product being pasteurized. 

Discharge Area 

The discharge is at the back of the tunnel pasteurizer. At this point, the bottles/cans are  transferred from the internal mat/belt to the external conveyor. A good hand-off is required. 

Tunnel_Series_5_PRO Engineering Manufacturing Inc

PRO/Line Series 5 Tunnel Pasteurizer 
(Medium Sized Tunnel Pasteurizer) 

Heat Recovery System 

The main component of the heat recovery system is the heat exchanger. The heat recovery system takes heat from containers (bottles and cans are most common) at the discharge end of the tunnel by circulating water used to heat the containers and sending the hot water to the infeed end of the machine to start to heat the containers at the beginning of the pasteurizing process. 

There are various types and configurations of heat  exchangers: 

Plate Configuration Heat Exchangers  

  • Advantages:
    • Single, larger plate version can supply all the  needed energy 
  • Disadvantages: 
    • Requires shielding from possible steam leakage 
    • More expensive to clean and maintain 

Tube and Bundle Heat Exchangers  

  • Advantages:  
    • Very efficient heat transfer 
    • Easy cleaning by CIP 
  • Disadvantages:  
    • Multiple units are required 

Heat Sources 

Boilers 

Low-Pressure Steam 

    • Advantages:
      • This option doesn’t a need licensed  boiler operator/Less cost 
    • Disadvantages:
      • Much slower heat transfer occurs 

High-Pressure Steam 

    • Advantages: 
      • Faster heat transfer  
    • Disadvantages: 
      • Need licensed boiler operator   
      • Regulated by local authorities 

Super-heated Hot Water 

    • Advantages: 
      • More efficient heat delivery than low steam 
      • Doesn’t need as many components as steam to return condensate to boiler. 
    • Disadvantages: 
      • Regulated by local authorities  

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PRO/Line Series 14 
(Large Tunnel Pasteurizer) 

Spray Nozzles 

Nozzle sizes 

  • Large orifice (reduced clogging) (more expensive) 
    • Large Orifice Nozzle Versions 
      • Low flow, large droplets 
      • High flow, large droplets 
  • Small orifice (less expensive) (prone to clogging) 
    • Small Orifice Nozzle Versions 
      • Low flow, high velocity 

Spray Pans  

  • Easy to clean  
  • Prone to clogging 
  • Version 
    • High flow, low velocity 

Belts/Mats 

  • Plastic  
    • (easy to install) (light weight) (lower initial cost, higher  operating cost) (prone to chemical attack) (lower  maximum temperature) (easier to break) (require  frequent maintenance) (shorter life cycle) (susceptible  to UV attack) 
  • Stainless Steel 
    • (Higher initial cost) (longer life cycle) (greater chemical  resistance) (broader temperature range) (reduced  maintenance) (lower operational cost) 

Guides 

  • Commercially Available Product Guides 
    • (Readily obtainable) (market priced)  
    • (easier installation) (good for bottles and cans) 
  • Stainless Steel Guide Plates 
    • (Good for bottle lines) (poor for cans)  
    • (low maintenance) (long life) 

Fabricated Plastic Side Guides 

  • Various plastics are available 
    • Various levels of chemical resistance are offered  
    • More chemical resistance equals less physical flexibility 
    • Susceptible to UV attack 
    • Flexible plastics-good for can lines, fair for bottle lines 
    • Higher temperature rigid plastics available 

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Pasteurization Unit (PU) Monitor Hardware and Software 

Results displayed on Separate Laptop 

SUMMARY 

This is a basic guide that you can use when considering the purchase or the operation of a tunnel pasteurizer. PRO Engineering/Manufacturing has been refurbishing, designing and building tunnel pasteurizers for over 40 years. We offer the widest variety of small, medium and large sized tunnel pasteurizers along with batch pasteurizers. Contact us to learn more! 

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 great 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]

 

Previous Article: BATCH AND TUNNEL PASTEURIZATION FOR CIDER/HARD CIDER PRODUCTION

 

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]

Why Tunnel Pasteurize new and emerging beverages?

Food Safety in beer was once focused on undesired foreign materials and debris found in individual beverages cans and bottles. While still important, Food Safety in beverages today is mostly microbiological because breweries have moved far beyond producing only traditional beers.

We all know of examples of production and beverage sales environments where products are made, sold very quickly and in a tight geography…premises such as brewpubs and local neighborhood breweries which can offer a promise of freshness and competent storage of product between production and sale/consumption. But for any volume, sales must extend further, and quality must be assured for longer timeframes and across varying real-world conditions.

Approximately 70% of beer spoilage cases result from contamination by lactic-acid bacteria, which produce flavors considered to be undesirable in most beer styles. The remaining spoilage cases are caused by a range of wild yeasts, as well as aerobic and anaerobic bacteria, that are present in the brewery environment and can carry-over to the beer if rigorous hygiene is not maintained.

Microbial inactivation

Harmful pathogens are not able to grow in beer due to several microbiological ‘hurdles’ such as alcohol, low pH, low nutrient content and the presence of growth inhibitors such as isomerized hop acids.

In continued evolution within breweries and beverage plants of all sizes, beverages are coming from breweries these days that would not have been twenty years ago. We see the emergence and growth in popularity of novel alcoholic beverages that may contain added sugar, flavorings and colorings. We see alcoholic beverages based on extremely low malt- inclusion rates, the product being fermented ‘sugar brews’. Breweries today produce beers mixed with fruit juices, and natural sodas, and low alcohol, sweetened beverages appealing to non-traditional beer drinkers. We’re also seeing novel cannabis-isolate containing hybrid beverages, These new drinks offer fewer naturally-inherent microbiological hurdles for spoilage organisms.

Due to novel ingredients previously not involved in production, beverages need to address concerns over germination of spores, and the growth of pathogens and other spoilers not routinely encountered in the brewing industry. The pasteurization parameters to destroy the vegetative cells and spores of Bacillus spp. are higher than what is normally accepted as adequate for milk pasteurizing…. 170 deg F at ten minutes hold.

The most common spoilage organism of tomato juice, B. coagulens produces lactic acid in package if not destroyed. In pineapple nectar, Byssochlamys nivea is a thermal resistant filamentous fungi (mould) with mycotoxin-producing potential that needs high sterilizing temperatures equivalent to tomato juice. Not every alternative product requires as aggressive a pasteurizing regime, of course. There are some new products, such as cold-brew coffees, that actually should go through much higher retort temperatures because the individual coffee beans, when dropped on the ground can make contact with botulism. Basic beer pasteurization does help cold-brew coffees and other novel beverages in an essential way:

Coffee with residual sugar is prone to refermentation or spoilage and can easily become a problem. Canned and fermenting coffee creates alcohol and carbon dioxide. That CO2 will continue to build and the can will explode or, in the case of a bottle, the cap/crown might pop off.

As a matter of fact, any beverage that is sweet or semi-sweet, has residual sugar…which is prone to refermentation in the closed package. The challenge for a retort temperature approach is readily seen in low acid products like banana and kiwi puree. Often, to inactivate spores and natural enzymes, a temperature much be reached that changes the color of the product being pasteurized. For example, a standard retort thermal treatment of these purees is at 130-135°C (266-275 F); due to this temperature the puree color changes to pink for banana and to brown for kiwi at 90-95°C (194-203 F). 

The only potential alternative to applying a retort regime is heavy pasteurization, storage and shipping of finished goods at refrigerated temperatures, and possible use of the common preservatives used by soft drinks manufacturers: potassium sorbate and sodium benzoate, in the event that the beverage is alcohol-free and non-acidic in nature. However, using preservatives is contrary to the “Clean-label” movement that seeks to eliminate preservatives, artificial flavors and coloring in food and beverage products.

New beverages

At one point in American brewing history, many breweries were making malt-based coolers, sometimes referred to as alcopops and later as FMBs. Some of the beverages used a natural dairy-based clouding agent (“Cloud”) or non-dairy based to make milky Pina Colada flavored drinks. The palette of available natural clouding agents today is much broader.

Non-alcoholic plant-based beverages might be made up of about 90% water, sugar, flavoring …but plants parts have constituted the main raw materials in these beverages…and source of microbiological concern. Soybeans are used for the production of soymilk, rhizome of ginger plants for ginger beer, sorghum or other grains, sweet potato extracts, water extracts of flowers (such as roses or hibiscus) and leaves (especially tea leaves). Soymilk contains 26.25% protein, 22.24% oil, 21.55% total solids, 4.55% Ash, 24.4% carbohydrate .

Ginger powder has 5.21% ether extract, 61.21% carbohydrate, 8.89% protein. 8.47% ash and 1.70% crude fiber. Common microbial challenges for soymilk would be Pseudomonas spp., and for ginger beer, Lactobacillius, Leuconostoc, Bacillus, Staphylococcus, Candida and Saccharomyces. These species can be addressed in a tunnel pasteurizer.

So what other kinds of beverages benefit from tunnel pasteurization? Novel beverages including natural and botanical soft drinks, flavored malt beverages, novel alcoholic beverages which may or may not be carbonated, fruit-inclusive drinks, alcoholic spritzers based on neutral alcoholic bases brewed in breweries, canned cocktails, innovative hybrid beverages.

The process of pasteurization guarantees stability of the packaged product without refrigeration. In a PRO Engineering design, it is carried out in extensively proven-design pasteurization tunnels with various heating, retention, and cooling zones, in which heat transfer occurs through a water film formed by aspersion on the package. The process is dimensioned in “Pasteurization Units” (PU), in which 1 PU is equivalent to 1 minute at 60 ºC,

Raising the pasteurization temperature to 68 ºC will yield 14 PU if held for 1 minute, and a temperature of 77 ºC and holding 1 minute realizes 268 PU. By changing the hot water spray setpoints and dwell time within the pasteurizer zones, a PRO Engineering pasteurizer can be designed, built and tuned to deliver 5 to 2500 PUs, depending on what the product in the individual package would require. PRO offers a batch-pasteurizer small footprint system for startups and exploratory projects, and all scales of continuous flow-through tunnel pasteurizers that can accommodate different packaged product volumes and packages (bottles or cans). Instrumentation such as a traveling tunnel PU monitor can be run through the pasteurizer to document adherence to target pasteurization parameters.

In the brave new world of alternative adult beverages, with alcohol or without, a batch- or tunnel- pasteurizer engineered for purpose by PRO and sized so as to meet line speed requirements for throughput represents how quality is robustly assured once the products leave the production facility.

Authored by Jaime Jurado

Past President-MBAA

(Master Brewers Association of the Americas)

https://www.linkedin.com/in/jaimejurado/

https://independent.academia.edu/JaimeJurado

Sponsored by Ed Michalski, CEO PRO Engineering and Manufacturing, Inc

PRO and Manufacturing, Inc has been providing equipment and engineering services to the beverage industry for 42 years. Contact Ed Michalski, CEO at: (414) 362-1500, [email protected]

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]

The Role of The Tunnel Pasteurizer: How Safe is Safe?

Creating and producing beverages are important to our lives and our livelihoods. As professionals, we are vigilant about food safety risks and taking very possible step to reduce as much as possible, conditions which create opportunity for problems.

The microbiological status of a packaged beer, especially one destined for a distant market, is of prime concern  and a brief Google browse shares, “the only satisfactory microbiological test is to pass at least 100 ml of beer through a 0.45 micrometer membrane, then plate the membrane on media (such as MRS or other media to be detailed) under conditions (for instance anaerobic at about 25° C) capable of detecting the target organisms in low number”.

Microbiological Media

As much as we would wish, a study of a beer samples under a microscope doesn’t work. Release of beer to the trade should await evaluation of its microbiological status, and it is possible, after sufficient time, to release products prior to having microbiological results, after ample opportunity to determine how ‘clean’ the tunnel pasteurized beer/beverage is. Some situations dictate that the packaged product is always held until complete micro release. The essential requirement of evaluation of efficacy is to carefully study a package of beer before it is pasteurized and after a package of the same beer batch has been pasteurized. Organisms are exposed to heat and the numbers surviving before and after treatment are determined. Viability is judged from the ability to multiply (to produce microcolonies).

Hsu’s Lactobacillus and Pediococcus (HLP) media can be employed to screen for common beer spoilers, while selecting against other organisms, such as yeast, gram negative bacteria and aerobic microbes (1). Other media include Lee’s multi-differential agar, Raka-Ray lactic acid bacteria medium, lysine medium, Lin’s wild yeast differential medium, Barney-Miller brewery medium, De Man Rogosa Sharpe medium, MYGP + copper medium, CLEN medium for wild yeast. The respected DIFCO Manual lists brewery-specific microbiological media (and their composition) including: Orange Serum Agar, UBA (Universal Beer Agar), Wort Ager, WL Nutrient Medium (Wallerstein Labs), WL Nutrient Broth, WL Differential Medium, YM Agar (Yeast Malt Extract), YM Broth. There are reported advantages to using various plating media.

For example, UBA supports growth of more varieties of lactic acid bacteria and yields larger quantities of these colonies in a shorter time, and it is a selective medium because within it, there is beer. Growth of microorganisms that have adapted themselves to thrive in breweries are detected.  The presence of hop constituents and alcohol eliminates the growth of many airborne pathogens. UBA supports growth of lactobacilli, pediococci, acetobacter and yeast strains robustly. Actidione at a level of 1 microgram per ml (1 ppm) is incorporated when samples containing yeast are cultured.

Temperatures to denature organisms and spoilage patterns

Industrial microbiologists have characterized the optimal temperatures for many species, i.e. brewing yeast 55 deg C;Moulds 65-80 deg C depending on species; Clostridium species (incl botulininum) 82-100 deg C depending on species.

The spoilage patterns of beer and ale  can be classified into four groups: ropiness, sarcinae, sourness and turbidity. Ropiness can be caused by Acetobater, Lactobacillus,  Pediococcus cerevisiae and Gloconobacter oxydans (formerly Acetomonas). Sourness arises from  Acetobacter spp. (which oxidize ethanol to acetic acid). Turbidity (and off-odors) in beer  may be caused by Zymomonas  anaerobia and several yeasts  such as Saccharomyces spp. In 1978, Coors Golden isolated Pectinatus cerevissphilius, which was then reported in other countries. Sarcinae is caused by P. cerevisiae, which will manifest a honey aroma and diacetyl flavor.

Packaged beer is susceptible to Saccharamoyces diastaticus, which can utilize dextrins in the beer which normal brewer’s yeast could not metabolize.

When this author worked in helping determine global tunnel pasteurization standards for one international brewing group, it was decided that the rate of under-pasteurized packages could not be less than one per 10,000 packages…which was the standard maximum-acceptable leaker rate at the time for the little milk boxes by Tetra-Pak used for school lunches (an interesting and completely unrelated comparator).

Using the Crystal Ball Monte Carlo add-on to MS Excel, it required a pasteurization target of 21 Pasteurization Units (PUs) to assure that the no more than 1 per 10,000 packages could be assured…when the real target was 15 PUs. This is the scrutiny that packages shipping all over the world require.

Yet it’s a different level of assurance required for beverages staying within a country and within a ‘normal’ shelf life. The simple question of “how safe is safe?’ relies on honest evaluation of what are valid criteria and the life of the packaged beverage after it leaves the brewery or beverage plant finished goods warehouse.

PRO Engineering can refer clients to specialized, certified, microbiological testing labs to help determine appropriate pasteurization levels, and a PRO pasteurizer can be configured to offer different pasteurization regimes. A fully-fermented alcoholic spritzer with flavors and no added sugar may require lower pasteurization than a barrel-aged beer. This author was fortunately in a large brewery setting with voluntary microbiological testing of pre- and post-pasteurized samples, when it was determined that 8 PU was a good target for a PRO tunnel pasteurizer. As mentioned, expert labs are available for confidential reporting and validation of acceptable post-pasteurization packaged beer and beverages.

What is desired is ‘non-detectable’ or  “less than 1” CFU/ml for aerobic bacterial testing, anaerobic bacterial testing, and yeasts and molds.

Tunnel pasteurization is a great means to achieve log-reductions of organisms that we don’t want in our beverages, a last defense bestowed on the beverages before they leave the facility. However, GMP and excellent cleaning and sanitation of all processes and unit operations (in bulk, in transport, and in packaging) prior to pasteurization are mission-critical to any ‘belt & braces’ approach to beverage quality assurance. The same goes for establishing an in-house microbiological testing lab. Regular and rigorous validation of microbiological status of packaged product for each batch is an expectation borne from prudence and the commitment to beverage quality assurance.

Authored by Jaime Jurado

Past President-MBAA

(Master Brewers Association of the Americas)

https://www.linkedin.com/in/jaimejurado/

https://independent.academia.edu/JaimeJurado

Sponsored by Ed Michalski, CEO PRO Engineering and Manufacturing, Inc

PRO and Manufacturing, Inc has been providing equipment and engineering services to the beverage industry for 42 years. Contact Ed Michalski, CEO at: (414) 362-1500, [email protected]

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]

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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