The Envelope


One of the Roaster Project design goals is to push the envelope of what a coffee roaster can do. In commercial design, a firm comes up with an operating envelope (max temp, max/min airflow, drum speed, etc.) deemed appropriate for the efficient roasting of most coffees. Safety, economic operation, practicality and stability are all considered.  Companies that operate commercial roasters appreciate these limitations.

The artisan, however, would like to be able to experiment and go outside of the “prudent” envelope. Therefore, the design envelope of the Roaster Project will be quite large, allowing for the artisan to test various theories. It is often through unconventional approaches that better ways are found. In all likelihood, the roaster will be operated within the normal envelope for most roasting, but having a tool that can go beyond is exciting and challenging.

Design Principles

1. Maximize the operating envelop

2. Design for manual control by an artisan including appropriate monitoring of operating variables

3. Adaptable to modern control systems for automated roasting

4. Separate variables as much as possible and be able to control each independently

5. Rated capacity of 10-15 kilos for personal scale in a shop setting

6. Broad operating range: consistent roast quality from 10% to 90% of rated capacity

7. Fine craftsmanship, designed for long service life

8. Style to conform with function fused with a Steampunk/Jules Verne aesthetic

9. Utilize local firms, craftsmen, talent

10. Energy efficient within the shop setting