Mill City Roasters Unveils M-Series Machines, Brings Manufacturing Home

Mill City Roasters has unveiled its new M-Series roasting machines—built entirely at a new 40,000-square-foot Minneapolis facility that marks a major shift toward domestic manufacturing.

The Minneapolis-based company, founded in 2013 by Steve Green with a mission to make specialty roasting more accessible, spent five years developing the M-Series. Every one of the 400-plus components in each machine now gets fabricated in-house using laser cutting, CNC machining, and precision welding.

“Having our own production facility 40 steps away from our designers makes everything seem possible,” says Vice President Angie Davis.

Engineering for Craft Roasters

The M-Series launches with 6kg, 10kg, and 20kg capacities, priced at $34,800, $42,800, and $64,800 respectively. Two more sizes—3kg and 30kg—are expected by summer.

The design centers on what Mill City calls a “monolithic chassis”—laser-welded plate steel construction that acts as a thermal battery. The idea is that the machine stores and releases heat predictably, letting roasters rely more on stored energy and less on constant burner adjustments. It’s an approach that rewards patience and precision.

Shaftless double-walled drums address another common pain point: uneven heat. The outer drum wall diffuses burner heat before it reaches the inner drum, reducing the hot spots that can scorch beans and create inconsistent roasts.

Smart Features Without Complexity

The M-Series control system uses a haptic jog wheel and RoastPath software integration, giving operators access to over 610,000 roast profiles through the Path Intelligence system. For roasters who want automation, optional packages handle fan speed, fuel, and drum rotation.

But Mill City hasn’t forgotten analog-minded roasters. The machines work perfectly fine without the smart features, and the solar-powered Minneapolis facility includes custom acoustic engineering to keep noise levels low—a practical consideration for roasteries that share space with retail or office environments.

Made in Minneapolis

The in-house fabrication represents a strategic bet. While many equipment makers outsource manufacturing to Asia, Mill City has invested in 6000-watt fiber lasers, 2000-watt laser welding systems, and high-precision CNC machines. The result is complete control over quality and lead times.

“If your coffee is a labor of love, your roaster should reflect an equivalent commitment to excellence,” says CEO Steve Green.

Why This Matters

For small-batch roasters, equipment choices define what’s possible. The M-Series sits in a price range accessible to serious home roasters scaling up and small commercial operations—the audience Mill City has served since its founding.

The machines debut at World of Coffee San Diego in April, where roasters can see the thermal battery concept in action. Mill City reports roughly two dozen pre-orders already logged, suggesting the industry is paying attention to this Minneapolis comeback story.