Green coffee beans can be roasted to perfection with a pop corn popper. The picture shows a Toastmaster pop corn popper, model TPC2.
Two minutes after insertion, the coffee beans should start popping.
Six minutes from the start the raw beans should be a shiny and greasy brown perfection. The longer the roast, the darker the beans.
Tips:
Roast outdoors. The beans will make lots of smoke and the aroma should be shared with neighbors.
Careful, the beans could burn if left too long.