Mill City Digital vs Manually Controlled Roasters?

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All Mill City Roasters have double walled drums, monolithic welded chassis, variable fan and drum speed, dedicated cooling fans, and integrated data logging.

Drum pressure is a feedback loop for fan speed. Drum speed control allows an operator to tune the machine for better performance across a broad range of batch sizes.

Our manually controlled roasters provide a modbus USB connection to RoastPATH that displays and records drum temp, bean temp, environmental temp, fan speed hz and drum pressure. Adjustments are made on the control panel with knobs for drum speed and fan speed. Gas adjustments are made by manually setting the gas valve and logged manually in the RoastPATH notebook.

The digital machines include the features of the manual machines, but also have “fly by wire” push button control over drum speed, fan speed, gas pressure. They include a fourth incoming air thermocouple, a digital gas readout, and state sensors for charge, discharge, and cooling tray discharge.

The digital machines offer sophisticated operator assist functions including automated cooling arm and cooling fan operation, and automated between batch recovery protocol.

The digital machines are also capable of a supporting RoastPATH “roast replay”. This function prompts the operator to charge the drum and follows any saved RoastPATH profile by precisely executing changes in fan, fuel, and drum speed recorded in a previous roast. At the end of the roast the system prompts the operator to discharge into the cooling tray.

There is a lot to know about our roasters that isn’t automatically obvious from the website. Maybe give me a call and I’ll walk you through why we build the way we do and how it will help you sell more and better coffee.


Steve Green | Mill City Roasters
Ph: 612.886.2089

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