Design of Portable Coffee Roaster for Home Industry

At present, the availability of an appropriate roaster for home coffee processing industry is very limited. This study aims to design a portable coffee roaster with a maximum capacity of 2 kg per batch. The roasting machine is designed with six main parts, namely as a roasting cylinder, an outer cylinder equipped with an inlet-outlet funnel, a main frame, a heat source with the LPG fuel, a cooling unit, and a temperature control system. The roasting machine has been tested to roast an amount of green bean at a constant temperature of 225 °C with three targets of roasted degree, namely as light, medium and dark. The test result shows that the roasting machine can work properly. The temperature control system is able to regulate the roasting temperature as same as the temperature target during the process. With the stable temperature, the machine can roast the green coffee sample to reach the target roasted degree with good result. The test shows that the roaster can roast the sample of 1 kg of green bean at light roast degree with an average time of 13.2 minutes and an energy consumption of 4708.92 kJ. For the same amount of sample, the coffee roaster can work properly for the roast degree target of medium with an average time of 16.9 minutes and an energy consumption of 4708.92 kJ. Meanwhile, for dark roasted target, the roaster requires an average time of 28.59 minutes and consume an energy of 9417.85 kJ.