CONRAD® Freeze Dryer

Benefits of processing freeze-dried coffee on the GEA CONRAD®: 

• Maximized uptime enabled by continuous, 24/7 processing - 8000 hours per year 
• Preservation of key aromas 
• Even heat transfer to the product 
• Uniform final product quality 
• Minimal product loss – less than 0.1% - during drying 
• Low comparative energy consumption  
• Compact design thanks to internal condenser system 
• High efficiency 
• GEA CONRAD® ECO models offer even greater energy efficiency  

So how does freeze drying of coffee work? 

Freeze drying typically creates higher quality instant coffee than spray drying, because freeze drying is carried out at very low temperatures (-50°C in a vacuum), which preserves much more – up to 90% - of the volatile coffee aromas. In contrast, spray drying uses high heat, which can degrade aromatic compounds and sensitive coffee oils.  

The freeze drying process is carried out in stages. Precisely weighed, preprepared frozen coffee extract granules are loaded onto trays, which are introduced into the freeze drying chamber via an airlock. The pressure in the chamber is constantly kept low and heat applied to the trays via heating plates, which causes the ice to turn directly into vapour, a process called sublimation. This water vapor is collected in a condenser and removed. In a secondary drying phase the temperature is further increased to remove remaining water in the frozen coffee extract. The drying conditions, including temperature, pressure, and residence time, are precisely adjusted in each zone of the CONRAD® to create a final premium quality product with exactly the right residual moisture content. 

Technology of choice for high capacity coffee freeze drying 

The CONRAD® technology enables continuous processing at high capacity.  
Continuously, trays filled with frozen coffee granulates are stacked and pushed through sequential drying zones for primary and secondary drying. Trays arriving at the dryer exit are then unloaded through an airlock, and the product is emptied from the trays, which are returned to the start.  GEA CONRAD® freeze dryers are equipped with an internal vapor condenser system that features our unique, continuous de-icing technology, enabling automated condenser de-icing without loss of operating vacuum. It’s this technology that lets the CONRAD® carry out continuous, rather than batch-process freeze drying. Compared with external condenser systems our space-saving technology is also more reliable, minimizes product loss to 0.1%, and uses less energy, for more efficient, productive manufacturing.  

At our test center, working with your product we can measure extraction yield, identify optimal drying conditions, and simulate the full evaporation and freeze drying process as part of a complete line evaluation, from roasted beans to final product.