Tunnel Pasteurization

Tunnel Pasteurization with Dynamic PU Control

Molenaar’s Dynamic PU Control Pasteurization Tunnels deliver precise, consistent pasteurization while protecting product quality — ideal for products where flavour, colour, aroma, carbonation or shelf stability can be affected by over-processing. By controlling the pasteurization profile in real time, the system achieves the required Pasteurization Units without unnecessary heat — supporting food safety, consistency and reduced waste while improving efficiency across high-volume lines.

Precision

Precision Pasteurization for Sensitive Products

A Pasteurization Unit (PU) measures the heat applied to a product over time, relative to a reference temperature specific to that product. Different products need different profiles depending on composition, pH and process. The correct PU is critical: too little heat can compromise safety and shelf life, while too much can degrade flavour, colour, aroma or other quality characteristics. Dynamic PU Control is particularly valuable for sensitive products such as:

Beer
Cider

How It Works

How Tunnel Pasteurization Works

Tunnel pasteurization moves filled, sealed containers through a series of controlled heating, holding and cooling zones. Products are gradually heated to the required pasteurization temperature, held for the necessary time, then cooled in a controlled manner.

Molenaar tunnel pasteurizers are engineered to deliver consistent temperature control across the tunnel, ensuring products receive the correct thermal treatment as they move through the line.

The Differentiator

Dynamic PU Control During Line Stoppages

In an ideal line, production runs continuously. In reality, downstream stoppages, changeovers or packaging issues can leave containers stationary inside the tunnel — and without advanced control, stationary products keep receiving heat, risking over-pasteurization and quality loss.

Molenaar’s Dynamic PU Control addresses this by automatically adjusting temperatures in individual tunnel zones during stoppages. Even when containers are stationary, it manages the heating and cooling profile to maintain the correct pasteurization curve and avoid exceeding the target PU. Once production restarts, the tunnel rebalances temperatures in real time to return products to the correct processing profile.

Engineering

Engineering Features That Support Consistent Pasteurization

Molenaar tunnel pasteurizers are designed for performance, reliability and ease of maintenance. A key feature is the use of cascade shower trays instead of conventional spray bars. These maintain a consistent depth of water and deliver a defined flow pattern over the products, supporting uniform heat transfer and reducing the risk of blocked nozzles or misdirected spray patterns.

High-volume water flow for improved heat transfer
Closed-loop water systems to minimise consumption
Easy inspection and maintenance via accessible trays
More predictable thermal performance
Consistent pasteurization outcomes
Reduced risk of unnoticed process issues

Molenaar also manufactures its own shell-and-tube heat exchangers, allowing for long-term reliability and customisation according to client requirements.

Efficiency

Energy Recovery & Efficient Operation

Molenaar integrates energy regeneration into its tunnel designs. Heat recovered from outgoing pasteurized products can be transferred to incoming colder containers, reducing both heating and cooling demand. This closed-loop approach supports:

Lower energy consumption
Reduced water usage
Improved operational efficiency
More sustainable production
Better use of recovered process heat

At a Glance

Benefits of Dynamic PU Control

Increased line efficiency
Improved product quality and consistency
Reduced risk of over-pasteurization
Reduced product waste
More stable performance during stoppages
Better protection of flavour, colour and aroma
Improved energy efficiency

Tailored

Designed Around Your Production Requirements

Every product and line has different pasteurization requirements. Molenaar works with customers to design tunnel systems around specific products, packaging formats, throughput and operational goals. Whether the need is high-volume beverage pasteurization or a specialised thermal process for sensitive packaged products, Dynamic PU Control Pasteurization Tunnels are engineered to deliver precise, reliable and efficient performance.

Explore

Precise Pasteurization, Protected Quality

Talk to Molenaar about a Dynamic PU Control pasteurization tunnel designed around your products, packaging and throughput.