Processing Shelf-Stable Beverages: Best Practices for Safety and Quality
Introduction
The demand for shelf-stable beverages continues to grow across categories, from juices and ready-to-drink teas to dairy-based and plant-based protein drinks. However, ensuring both safety and product integrity requires a clear understanding of processing methods, particularly as they relate to high-acid vs. low-acid beverages.
The difference in pH classification determines the thermal processing requirements, microbial risks, and stability challenges of the product. While high-acid beverages (pH ≤ 4.6) are less prone to harmful bacterial growth, low-acid beverages (pH > 4.6) require more stringent sterilization processes to prevent dangerous contamination, including pathogens like Clostridium botulinum.
This white paper outlines best practices for processing high-acid and low-acid beverages, common formulation challenges, and key factors for ensuring a safe, high-quality final product.
High-Acid Beverages: Processing Considerations
Definition & Common Products
High-acid beverages have a pH of 4.6 or lower, making them naturally more resistant to microbial growth. Common examples include:
- Fruit juices and nectars
- Carbonated soft drinks
- Certain flavored waters and functional beverages
- Fermented beverages (e.g., kombucha)
While these beverages do not support the growth of harmful bacteria, spoilage from yeasts and molds remains a concern, making pasteurization an essential step.
Processing Methods for High-Acid Beverages
Several heat processing methods are commonly used for high-acid beverages:
- Hot Fill Hold (HFH)
Hot Fill Hold (HFH) is a method used to ensure both pasteurization and packaging sterilization by heating the beverage to a high temperature, filling it hot into containers, sealing them, and maintaining a specific temperature for a set duration. This process is highly effective for glass and plastic bottles but is not suitable for packaging materials that are sensitive to heat.
- Tunnel Pasteurization
Tunnel pasteurization is a process in which beverages are filled cold and then heat-treated post-filling within a tunnel where hot water or steam circulates. This method is highly effective for glass bottles and cans, though it necessitates precise thermal profiling to ensure consistent and safe results.
- High-Temperature Short Time (HTST) Pasteurization
High-Temperature Short Time (HTST) pasteurization involves rapidly heating a beverage to a temperature of 85°C–100°C, holding it for just a few seconds, and then cooling it quickly. This method effectively inactivates spoilage microorganisms while preserving flavor and nutrients, making it a popular choice for juices, teas, and non-carbonated functional beverages.
Challenges in High-Acid Beverage Processing
- Ingredient Interactions with Heat
Ingredient interactions with heat can present challenges in beverage processing. Ingredients such as cocoa and plant-based powders often prove difficult to disperse uniformly, potentially creating hot spots that result in uneven pasteurization. Natural and minimally processed powders may carry higher microbial loads, necessitating more aggressive thermal treatments to ensure product safety.
- Packaging Considerations
Packaging considerations play a critical role in beverage processing, as some plastics and eco-friendly materials may not withstand specific heat treatments. It is essential for beverage developers to ensure that the chosen packaging is compatible with the pasteurization methods being used to maintain product safety and integrity.
- GMP & Process Validation
Even in high-acid beverages, spoilage organisms like yeasts and molds can thrive if GMPs (Good Manufacturing Practices) and sanitation protocols are not rigorously followed.
Low-Acid Beverages: Processing Considerations
Definition & Common Products
Low-acid beverages have a pH above 4.6, creating an environment where dangerous bacteria, including Clostridium botulinum, can grow if not properly processed. Common examples include:
- Dairy-based and plant-based milk beverages
- Protein shakes and meal replacements
- Coffee and tea lattes
- Energy drinks with added proteins or dairy
Processing Methods for Low-Acid Beverages
Due to the high pathogenic risk, low-acid beverages require sterilization-level heat processing:
- Retort Processing
Retort processing is a technique in which beverages are filled into sealed containers and subjected to high heat under pressure, typically at temperatures of 121°C or higher. This method effectively eliminates all bacteria, including spores, ensuring product safety and extended shelf life. It is commonly used for canned and bottled beverages.
- Aseptic Processing & Packaging
Aseptic processing and packaging involve sterilizing the beverage and packaging independently, followed by filling the product in a sterile environment. This method ensures an extended shelf life without the need for refrigeration, making it ideal for products like ultra-high temperature (UHT) dairy and plant-based milks. Common packaging options for aseptic processing include cartons, pouches, and PET bottles.
Challenges in Low-Acid Beverage Processing
Ingredients, formulation, and regulatory compliance are critical considerations in beverage processing.
- Heat Sensitivity of Ingredients
Heat-sensitive ingredients such as dairy proteins and vitamins can degrade under prolonged high temperatures, making specialized thermal profiling essential to preserve their integrity
- pH and Formula Adjustments
Small pH shifts caused by added flavors or stabilizers can alter microbial risks, necessitating adjustments in the required heat treatment to maintain safety.
- Regulatory Compliance & Process Validation
Compliance with FDA and USDA regulations mandates process validation for low-acid beverages to ensure they meet safety standards and protect consumers.
Common Mistakes in Shelf-Stable Beverage Processing
Underestimating Food Safety Risks
While some brands prioritize taste and formula in their products, they often neglect the critical aspect of microbial safety. To prevent costly and potentially dangerous miscalculations in thermal processing, partnering with experienced process authorities is essential.
Neglecting Ingredient-Specific Processing Needs
Ingredients react in unique ways when exposed to heat during processing. It is critical to understand how the ingredients in your beverages will perform at varying temperatures. For example:
- Plant-based proteins can coagulate.
- Cocoa and other powders may require additional dispersion techniques.
- Natural colors can fade under high heat.
Inconsistent GMPs & Poor Copacker Oversight
Inconsistent Good Manufacturing Practices (GMPs) and inadequate oversight of copackers can lead to serious issues in beverage production. Even the most well-processed beverages risk post-filling contamination if sanitation and packaging protocols are insufficient. To ensure product quality and safety, process validation at copackers is essential.
Regulatory & Industry Trends Driving Reformulation
Stricter food safety regulations from the FDA and USDA are tightening thermal processing requirements for low-acid beverages, compelling brands to meet these expectations to avoid costly recalls. Meanwhile, growing consumer demand for clean label products pushes companies to create preservative-free, natural beverages with extended shelf lives, presenting a complex challenge that requires expert formulation. Additionally, advances in processing technology, such as new aseptic and retort methods, enable improved flavor retention and stability without compromising safety, further shaping the evolution of beverage production.
Partnering with The National Food Lab (The NFL)
Shelf-stable beverage processing is complex—working with experts ensures both safety and quality. Our team has extensive experience in beverage formulation, thermal processing, and regulatory compliance, helping brands:
- Navigate the challenges of high-acid vs. low-acid processing.
- Develop stable, safe products with optimized shelf life.
- Validate copacker processes to ensure compliance and quality.
- Troubleshoot ingredient-specific heat treatment challenges.
If you need support developing or optimizing your shelf-stable beverage, our experts are here to help. Contact us today to discuss your formulation and processing needs.
Meet the Author
Terry Berman
Terry Berman brings over three decades of experience in food product and process development to his role at The National Food Lab (NFL). Having worked with companies of all sizes, Terry’s expertise and knowledge make him an asset to The NFL team.
Terry earned his B.S. in Microbiology from Ohio State University and his MBA in Marketing from the University of New Haven. He joined The NFL in 2009 and has since then worked in various capacities, including overseeing pilot plants, sample production, Process Authority services, business development, and account management.
Terry’s commitment to innovation and delivering the highest quality solutions has earned him recognition as an industry leader.
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