The roasting process

 

Our roasters Tropic Coffee use a late 1950s 76kg Whitmee ‘Open flame’ roaster is a legacy of Great British Engineering. The cast iron bodied roaster features a perforated drum with the gas flame apertures in the Centre of the drum rather than underneath it, therefore a truly direct flame.

 

 

Roasting Coffee with the 1950s Whitmee Open Flame Roaster is both an art and a science, and using a vintage machine like the 76 kg Whitmee Open Flame Roaster brings a unique, nostalgic charm to the process. This cast iron roaster, a legacy of Great British Engineering, features a perforated drum with gas flame apertures in the centre, offering a truly direct flame experience. Let's walk through the roasting process step-by-step.

Preparation

Before we start roasting, we ensure the roaster is clean and ready to go. Clear out any leftover coffee beans or debris from previous roasts. Double-check that the gas supply is securely connected and functioning properly. Proper preparation sets the foundation for a smooth roasting session.

Preheating the Roaster

Light the gas flame and set it to a medium setting. Allow the roaster to preheat for about 15-20 minutes. This step is crucial as it ensures the cast iron body reaches an even temperature, which is essential for an even roast.

Loading the Beans

Measure out our small quantity of green coffee beans, the maximum capacity we usually roast at is 3-4kgs per batch. We then Carefully load the beans into the perforated drum, making sure it is securely closed before we begin the roasting process. Safety first!

The Initial Roasting Phase

We start the roaster and maintain the flame at a medium-high setting. Keeping a close eye on the beans, stirring occasionally to ensure they heat evenly. During this phase, the beans will slowly start to yellow and emit a grassy aroma. It's the beginning of their transformation.

Listening for the First Crack

As the beans heat up, we listen for the first crack, which sounds like popcorn popping. This typically occurs around 195°C. Once we hear the first crack, we reduce the flame slightly to avoid scorching the beans. The first crack signals that the beans are entering the development phase.

The Development Phase

After the first crack, we continue roasting for 2-5 minutes, depending on our desired roast level. During this phase, the beans will darken and develop more complex flavours. We keep a close watch to prevent over-roasting. The beans should reach their optimal roast level just before the second crack.

Considering the Second Crack

If we are doing a darker roast, we listen for the second crack, a quieter sound that occurs around 225°C. If we are roasting medium, we stop the roast before the second crack begins. Timing is key in achieving the perfect roast.

Cooling the Beans

Once we have reached the desired roast level, we quickly turn off the flame and open the drum.  Then we transfer the roasted beans into a cooling tray or mechanism immediately to halt the roasting process. Stirring the beans in the cooling tray helps them cool evenly, locking in their freshly roasted flavour.

Storing Your Roasted Coffee

After the beans have cooled, we store them in airtight containers. This lets the beans rest for 24 hours before grinding and brewing. This resting period allows the beans to degas and develop their full flavour profile, ensuring a rich and satisfying cup of coffee.

Clean Up

Finally, we clean the roaster thoroughly, removing any chaff or debris. Proper maintenance ensures that our Whitmee roaster is ready for the next roasting session and extends its lifespan.

Embrace the Charm of Vintage Roasting

Roasting coffee with the 1950s Whitmee Open Flame Roaster is more than just a process—it's an experience that connects us to the rich history of Great British Engineering. The unique design of this roaster, with its direct flame and cast iron body, offers a distinct roasting experience that modern machines simply can't replicate. We thoroughly enjoy the journey of transforming green coffee beans into aromatic, flavourful coffee with this remarkable piece of machinery.

 

Why do we use Tropic Coffee for our roasts?

 

Tropic Coffee Ltd has been blending and roasting fine coffee for nearly 40 Years.

Founded in 1983 by the Managing Director Martin Sanctuary the Company remains family owned and operates from its factory in the historic town of Kings Lynn in Norfolk.