Design and manufacturing of portable coffee roaster Available to Purchase

One of the most important steps in coffee post-harvesting process is roasting green coffee beans after the coffee fruits being hulled. In order to obtain the best quality of premium-grade roasted coffee, certain parameters should be considered carefully. The quality and taste of roasted coffee is affected by bean temperature, airflow and stirring speed in the roasting process. In this design of portable coffee roaster, it is equipped by constant airflow and PID-based temperature control with solid-state relay and programmable Arduino microcontroller. The roast temperature was set by before roasting process which the difference between the pre-set temperature and bean temperature is read by a K-type thermocouple, then the difference value is calculated by the PID controller in Arduino which the PID output determine the electrical power that transferred to the heating elements. This article addressed the design and manufactured portable coffee roasting of 300 gram. The machine was powered by electrical equipment using heating element of 800 w. The machine has vertical drum as main container where heating process occurred. The minimum temperature is 145°C and maximum temperature of 215°C. The grade of the roasted product varies within a single batch of coffee due to the hand-operated stirring process. The next possible improvement is the automation of the stirring process.