New Five-Kilo Coffee Roaster: Build Notes from Worker Coffee

If you've ever roasted more than a couple of kilos at a time and felt your machine lag behind your roast plan, you're not alone. Many specialty roasters hit a wall when scaling up—either their roaster can't maintain heat stability, or the airflow isn’t responsive enough to develop the Maillard reaction evenly. That’s where a purpose-built five-kilo machine makes all the difference.

The newest five-kilo roaster from Worker Coffee is built entirely by hand, with a high-output flame system, concealed dust collection, rear exhaust routing, and smooth, lag-free controls for both flame intensity and air intake—delivering the kind of responsiveness that matters when you're fine-tuning a Yirgacheffe or pushing a Sidra into second crack.

What’s Different About This Five-Kilo Roaster?

This isn’t a scaled-up version of a smaller machine. Worker Coffee has produced several four- and five-kilo models recently, but this unit uses an updated configuration with reinforced components throughout. Every part was fabricated manually—not outsourced or adapted from industrial parts—to ensure thermal consistency and precision control.

Key features include a powerful and responsive burner system, an integrated but hidden dust collection bin, and a rear-positioned exhaust design. These aren’t just cosmetic upgrades—they influence how heat and chaff are managed during the roast, directly affecting bean development.

Build Process: Handmade with Precision

The entire roaster was assembled by hand, with careful attention to heat flow and mechanical response. The goal wasn’t just to handle five kilos, but to roast it predictably and repeatably. Every weld, joint, and control linkage was custom-fitted to reduce lag between adjustments and actual roast behaviour.

That includes the flame and air door systems, which respond instantly to roast phase changes—something that’s critical when transitioning from drying to Maillard to development, especially in denser single origins.

Why These Features Matter for Roast Quality

A five-kilo batch needs more than just capacity—it needs airflow that can clear chaff without cooling the drum, and heat delivery that doesn’t spike or stall. The Worker roaster’s rear exhaust system helps route hot air and particulate away efficiently. The hidden dust collector keeps the workspace cleaner and reduces fire risk. Most importantly, the flame and air controls operate smoothly without delay, letting the roaster adjust in real time during exothermic phases like first and second crack.

All of this adds up to a machine that doesn’t just roast bigger batches—it roasts them with the finesse needed for specialty profiles.

Frequently Asked Questions

What size batches does this roaster handle?

This is a five-kilo capacity roaster, designed to roast up to five kilograms of green coffee per batch. It’s aimed at specialty roasters looking to scale production while maintaining precise control over roast profiles.

Is this roaster commercially available?

The article does not specify whether the roaster is available for purchase or distribution. It appears to be a custom-built unit from Worker Coffee, possibly for in-house or limited use.

What are the key features of the roaster?

Key features include a high-power flame system, concealed dust collection bin, rear exhaust system, and responsive manual controls for flame and air intake. These allow for stable heat application and better chaff management during roasting.

Was this roaster mass-produced?

No, the article states that this is a handmade unit, part of a series of four- and five-kilo machines. Each unit is built individually, not mass-produced, with an emphasis on custom fabrication and mechanical precision.

How does the exhaust system improve roasting?

The rear-mounted exhaust system helps manage heat and chaff more effectively, reducing temperature spikes and keeping the roasting chamber stable. This contributes to more even development and better control over the roast profile.

What makes the controls 'lag-free'?

The roaster’s flame and air door adjustments respond immediately to operator input, without delay. This is crucial during dynamic roast phases such as Maillard reaction and first or second crack, allowing precise tuning of roast development.

Recommended FrontStreet Coffee for Five-Kilo Roasting

For roasters working with a five-kilo drum like Worker Coffee’s new build, FrontStreet Coffee’s Ethiopia Humbera offers vibrant floral and citrus notes ideal for testing heat retention and airflow control. Their Yirgacheffe brings lemon, jasmine, and stone fruit—perfect for dialling in gentle Maillard transitions. For darker profiles, try their PWN Golden Mandheling with its deep caramel and woody tones, great for experimenting with development time. All are excellent for refining your roast curve on a mid-sized machine. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.