The idea for a small, home roaster came to James in Milan. He was in a park and thinking about how much money he'd been spending on roasted beans. His solution was build a roaster of his own. He made a few sketches and resolved to build the machine when he returned home.
To start with, an oven type needed to be selected. This convection oven uses a halogen bulb to heat the machine. An internal fan disperses the hot air inside the machine which allows the hot gas to circulate and roast the beans.
Microsoft Excel is used to log the data coming from the machine. A micro-controller monitors the roast. The program installed in the micro-controller very specifically matches a roasting curve giving the user unparalleled control over the roasting process.
The green beans are mixed using a small motor and a stainless steel T piece. This allows the beans to roast evenly.
PID control is widely used in engineering applications for process control so James used it here. The program senses the temperature of the beans and decides to turn the element on or off. By doing this the amount of heat required to roast is precisely incremented throughout the roast.
What started out as a small sketch lead James to find out what he was really passionate about. He'd like to share that same passion with everyone else through Williamstown Roasters in the hope you get as much enjoyment out of excellent coffee as he does.