Bühler’s new Lucent cocoa roaster

Swiss technology group Bühler has developed Lucent, a new industrial cocoa nib roaster that uses at least 20% less energy per ton of cocoa than its predecessor, the Tornado, and delivers up to 20% higher throughput in the same footprint. 

Developed by Bühler’s engineers and manufactured in Appenzell, Switzerland, Lucent combines heat recovery, predictive roasting controls, and a fully sealed product chamber. Together, these features address key demands in industrial cocoa processing: productivity, energy efficiency, and food safety. Lucent is now available to industrial cocoa manufacturers worldwide.

Cocoa processors face sustained pressure from volatile cocoa prices, rising energy costs, and tightening margins. Energy is one of the few input costs they can directly control. It accounts for 10 to 20% of total operating expenses in cocoa processing, with roasting as the single most energy-intensive step. For decades, that step has changed little in fundamental design. Bühler’s Tornado roaster, a widely used industry benchmark, operates as a batch process in which hot air roasts the cocoa in a rotating drum and exhaust air is vented after each cycle, taking a significant share of thermal energy with it.  

Lucent, Bühler’s new cocoa nib roaster, recovers that energy. A heat exchange system uses return air, reducing the load on the gas burner. A redesigned drum geometry and optimized fill levels reduce gas consumption by at least 20%, compared to Tornado, while increasing throughput by up to 20% without adding to the machine’s physical footprint. 

A hybrid roasting option, combining convective and conductive heat transfer, is also available and can achieve up to 40% energy savings in specific applications. “Roasting is where flavor is created. It is one of the steps our customers care about most, and it has historically been the step where the most energy is wasted. Lucent enhances flavor control while reducing energy use,” says Isabelle Kirckof, product manager market segment, cocoa & malt at Bühler. 

Food safety by design

Lucent features a fully enclosed roasting chamber and a new sealing system that physically separates the product from combustion air throughout the entire roasting cycle. The machine is constructed in stainless steel with an easy-clean finish and includes service openings that provide direct access to key components, reducing maintenance time and facilitating inspection. The design also reduces yield loss, a known limitation in the previous generation of roasters where the product could be drawn into the airstream. 

“Food safety standards in the cocoa and chocolate industry are tightening, and our customers need equipment that meets those standards structurally, not through process workarounds,” says Joachim Essig, head of sales cocoa & malt at Bühler. 

Predictive controls and ease of operation 

Lucent uses a self-learning control system that continuously monitors key roasting parameters and automatically adjusts gas burner temperature, airflow, and process speed. An operator sets a roasting profile; the algorithm manages execution. Depending on the raw material, roasting cycles run between 40 and 60 minutes. The system adapts to variation in incoming cocoa to maintain consistent results from batch to batch.  

The controls are designed to reduce the dependency on specialist machine knowledge. An operator sets a roasting profile; the system manages execution, adjusting temperature, airflow, and process speed in real time. Consistent output no longer depends on reading the roast by experience alone. “Roasting has always been as much about expertise as technology. Lucent combines both by embedding process knowledge into the machine, making repeatable flavor profiles and consistent roast levels easier to achieve,” says Isabelle Kirckof. 

Developed from customer feedback, made in Switzerland 

Lucent’s development drew directly on feedback from Bühler’s industrial cocoa processing customers. Priorities identified in this process – energy efficiency, hygiene, throughput, and operational simplicity – led to design choices such as fully enclosed chambers, an integrated heat recovery system, and service openings that provide direct access to key components. A prototype is currently in development and will be installed at a customer site in Asia in the first quarter of 2027. Further applications in roasting other commodities are planned over the next two years. 

Lucent is manufactured entirely at Bühler’s facility in Appenzell, Switzerland, the company’s center of excellence for cocoa processing equipment. Since 2022, all key components for Bühler’s cocoa processing lines have been produced there, from infrared pre-treatment machines to roasters and coolers. Bühler has continuously invested in the site’s engineering capabilities, training, and manufacturing technology, making Appenzell the origin of cocoa processing equipment operating in plants around the world.