Batch retorts vs. Continuous Sterilizer: which solution is right for you?

Surdry North America CEO Julian Stauffer explains the key differences between Surdry’s batch retorts and its Continuous Sterilizer. Read more to discover the unique advantages of each system and how they can impact production, energy efficiency and profitability.

Surdry’s recently launched Continuous Sterilizer has sparked excitement among food and beverage manufacturers, thanks to its impressive efficiency and energy-saving capabilities. However, it also raises questions about which system—batch retorts or continuous sterilizers—offers the best food processing solution for maximizing profitability, minimizing energy consumption and optimizing production lines.

To address these questions, we sat down with Surdry North America CEO Julian Stauffer, who explains which system is best suited to a company’s operations, considering various business factors.

From a financial standpoint, what key factors should businesses consider when choosing between batch retorts and continuous sterilizers?

Julian Stauffer: When evaluating any financial capital investment in machinery, it’s essential to consider the total cost of ownership (TCO). This includes both the upfront costs — such as equipment, accessories, shipment, installation and commissioning — and the long-term operating costs, including production, labor, maintenance, energy consumption, etc. The Continuous Sterilizer technology requires a higher investment upfront but offers lower operational costs over its lifetime. In contrast, batch retorts have a lower upfront cost but tend to have higher operational costs compared to continuous sterilizers. A key factor to consider is the required production speed. Manufacturers should likely opt for the Continuous Sterilizer technology for high output, dedicated production lines. It can run non-stop to meet production output requirements. However, a batch retort might be a better fit for high output operations with a wide variety of product sterilization recipes requiring more frequent changeovers or scheduled downtime.

For smaller production volumes or lower production speeds, starting with one or two batch retorts and adding incremental retorts overtime makes more sense from a financial standpoint.

How do operating costs differ between batch retorts and Continuous Sterilizers over the long term? How might that impact overall profitability?

Batch retorts have significantly higher operational costs over time compared to continuous sterilizers. This is due to the constant heating and cooling cycles in batch retorts, where the system frequently turns on and off. In contrast, continuous sterilizers maintain steady, uninterrupted operation, heating up once and maintaining desired temperatures continuously until production is complete. This efficiency leads to dramatic cost savings, especially in time and energy — our Continuous Sterilizer, for example, consumes up to 50% less energy than batch retorts. These factors, combined with other minor efficiencies, boost profitability, even if both systems produce the same output.

What technical factors could make batch retorts or continuous sterilizers more financially advantageous?

Batch retorts’ flexibility can make them more financially advantageous. They can handle various package formats, product recipes and processing times, offering a versatile solution. Additionally, the manufacturer is not dependent on a single retort—they can operate multiple retorts simultaneously. If one breaks down, the others can continue running, minimizing downtime. This flexibility can ultimately lead to increased revenue for companies using batch retorts in their production operations.

On the other hand, continuous sterilizers offer advantages in energy efficiency, time savings and production throughput, which can lead to increased revenue. However, the downside is that if a continuous sterilizer goes down, it can halt production entirely, resulting in significant revenue loss.

These factors are key in weighing the benefits and risks of selecting a continuous sterilizer, and they are what ultimately tip the scale one way or the other.