Caloris Low-Spore Process
The Spore Problem
Many processors face the challenge of achieving consistent daily production of milk powders with low spore counts. The presence of a nominal level of spores in milk powders is difficult to avoid because of the presence of spores in the incoming raw milk supply, with those counts increased by a factor of 10 after processing the milk solids to a powder.

The Caloris Low-Spore Process won the 2018 ADPI Breakthrough Award for Dairy Ingredient Innovation. Read more here.
A critical challenge is the exponential growth in bacterial and spore counts to unacceptable levels that develop over the course of a daily production cycle due to growth of biofilms. In particular, the feed preheating and initial product concentration sections of the evaporator provide ideal growth conditions for biofilms formed by vegetative bacteria, and after a maturing period of ~10 hours those biofilms begin to contaminate the milk they contact for the remainder of the evaporator production run.

How can we help you?
Contact Caloris today for more information on our patent-pending low-spore process and how we can implement this solution into your operation. Email info@caloris.com to discuss your specific needs.
The Caloris Solution
In the past two years, two dairy processors have worked with Caloris to install new evaporator systems incorporating the patented Caloris Low Spore Process, and are now consistently and routinely producing high quality low-spore milk powders while maintaining continuous and uninterrupted operation of their spray dryer systems.
The key to the Caloris Low Spore Process is well-timed evaporator system CIP cycles, which eliminates operation with the presence of mature biofilms in the evaporator system before they begin to contaminate the milk product with spores. The configuration of the Caloris Low Spore Process allows for these CIP cycles to occur without interrupting the powder production of the spray dryer system.


“The concept struck us as simple, robust, and repeatable. We could clearly eliminate the risk of operating with the presence of mature biofilms that, in a traditional evaporator system, serve as a source for contamination of the milk product with spores.”
Caloris Customer
How It Works
Thorough cleaning just as the biofilms begin to reach maturity, prevents any significant contamination of the product with spores from biofilms. This also provides the added benefits of cleaning evaporator surfaces before they develop any significant solids fouling, allowing the evaporator to consistently operate at highest energy efficiency throughout the day, minimizing the soiling of recovered CIP chemicals and requirements for fresh make-up chemicals, and reducing the daily loading of waste solids discharged to the plant waste treatment systems.
To avoid any disruption to downstream spray dryer systems from frequent evaporator CIP cleanings, the Caloris Low Spore Process separates the initial Pre-Evaporator systems from the subsequent high concentration evaporator and spray drying systems. These Pre-Evaporator systems operate at ~20% above the capacity of the downstream high concentrator and spray dryer systems, producing an inventory of skim condensed sufficient to maintain uninterrupted spray dryer operation for two hours.
After a specific period of operation on product, the Pre-Evaporator systems undergo a complete CIP cycle (product-to-product) within a period of two hours, returning to production of skim condensed before the inventory supplying the spray dryer system is depleted. In the high concentration evaporator and spray dryer feed system components, the higher solids concentration suppresses the rate of biofilm formation and maturation, allowing those systems to operate continuously for longer periods of time without biofilms contaminating product.
Proven Results
The Caloris Low Spore Process has provided our customers with a routine and robust process for consistent production of high quality low-spore milk powders each and every day, utilizing standard operating procedures that are straightforward and repeatable. By implementing a dual feed system for their spray dryer, and utilizing dual high concentrating evaporators to alternately concentrate cold skim condensed for feeding the spray dryer system, these customers have the capability to maintain continuous and uninterrupted production of milk powders while consistently executing the frequent CIP cleanings of the feed preheat, HTST and Pre-Evaporator systems that ensures a consistent low-spore milk product quality.

Caloris Brochure
