Stronghold launches compact S2 roaster for precise micro-batch coffee roasting

Stronghold pushed its compact S2 roaster into global sales with a clear pitch: give sample roasters, home enthusiasts and tiny cafes the control of a production machine without the footprint of one. The 300-gram roaster is aimed at micro-batch work, but it is built to do more than casual home experimentation. Stronghold says the S2 is a high-precision electric machine for professional roasting, micro-lot production and advanced profile development, and the company has already shown there is demand. Coverage of the launch said Stronghold sold more than 500 S2 units in Korea and China in the machine’s first year of availability.

That kind of traction matters because the S2 sits in a useful middle ground. Stronghold says the roaster can handle batches from 80 grams to 300 grams, which makes it small enough for dialing in samples and far more serious than the toy-sized machines that often frustrate users with limited repeatability. Daily Coffee News described it as roughly two feet tall and about 60 pounds, with a vertical-drum design that blends convection, radiant heat and conduction to echo the behavior of Stronghold’s larger systems. For anyone trying to bridge lab work, home roasting and small café production, that is the point: one machine that can handle testing, repetition and modest daily output without jumping straight to a full commercial setup.

The biggest technical upgrade is control. Stronghold’s launch materials say Pro Mode gives 0.1-increment hot-air adjustment, instead of the 0.5-step jumps used on earlier machines. That finer resolution should make it easier to repeat a roast from batch to batch, especially when chasing small changes in development or airflow. The S2 also includes a manual trier, a glass viewing window, smoke-mitigation compatibility and touchscreen or web-connected control, so the machine is clearly aimed at users who want to watch, taste and adjust in real time rather than set it and walk away.

Stronghold’s rollout also leans on credibility. The company says it renamed itself Stronghold Robotics Co., Ltd. and moved to a new factory in Incheon, after first launching the S2 in Korea and China. It has also served as an official equipment sponsor for multiple World Coffee Roasting Championship and national roasting competitions, which helps explain why the machine keeps showing up in serious roasting conversations. Stronghold planned to show the S2 at World of Coffee San Diego, World of Coffee Bangkok in May and World of Coffee Brussels in June, and the machine was entered in the Specialty Coffee Association’s Best New Product Awards. With Ben Put, a seven-time Canada Barista Champion and 2025 World Barista Championship finalist, among the early testers, the S2 looks built to widen access to hands-on roasting without watering down the craft.