Engineering Innovation for Cherry Coffee Wet Processing Using Circulation System and Agitator Grading Machine

Abstract

Coffee cherry grading technology is currently advanced, but some adjustments to the method need to be made. So far, the wet treatment process uses much water. Therefore, an innovation is needed by adding a water circulation system equipped with a filter and agitator. The filters are useful for slowing down the degradation of water quality, and the agitator functions to moisten the cherry coffee evenly. This study applies an innovation of coffee cherry grading machines with semi-wash (soaking for 12-24 hours) and full-wash (soaking for 32-36 hours) methods. The focus is on the quality of the washing water, the water used, and the quality of the coffee beans produced. The results showed that in the semi-wash process, there was a decrease in turbidity of 5.1 NTU in the main tube, from 10.42 NTU to 5.32 NTU. Meanwhile, in the full-wash process, there was a decrease of 7.95 NTU, from 15.65 NTU to 7.70 NTU. The amount of water needed to process 7 kg of cherry coffee is 306.79 liters. The quality of the coffee beans produced was 7.58 mm on average, 6.80 mm on average, while 5.68 mm was small. This is in accordance with the SNI 01-2907-2008 standard, and the visualization of coffee bean results is in accordance with the standard of semi-washed green beans, namely bluish-green and full-wash results, which appear yellowish-green.