Who doesn’t know coffee? Almost everyone knows coffee, especially at this time around when the coffee industry continues to thrive and is popular among young and old alike. This is evident from large number of coffee shops that are open today, coffee is becoming a trend at home and abroad.

The process of making coffee certainly takes a long time, starting from planting seeds, picking seeds, sorting the beans according to their quality, stripping the skin, soaking, drying, grinding to make coffee powder before brewed and served with hot water. To support coffee processing, the Assessment and Application of Technology Research Organization (OR PPT) has developed a coffee auto roasting machine which has a number of advantages, just to name a few, evenly-matured coffee beans, perfect taste and aroma, free from epidermis, and high level of antioxidant.

The process of grinding coffee beans is one of the main focuses of the Agroindustrial Technology Center (PTA) of BRIN’s Assessment and Application of Technology Organization Research (OR PPT) in raising the topic of Fluidization Model-Coffee Roasting Machine Design at a Webinar on Agroindustrial Technology titled ‘Postharvest Research on Industrial Raw Material Plants’, Wednesday (12/1). OR PPT Associate Engineer Gigih Atmaji, in his presentation explained that the roasting stage has a very important role in the process. He added that the Fluidization Model has a uniform roasting result, both in terms of the yield and its consistency. “It separates coffee skins very well and the machine construction is almost free-maintenance,” he said.

Fluidization is a method used to create density with compressed air. The hot air in contact with the coffee beans makes the coffee beans spin and stir during the process by convective heat transfer. The fluidization method in roasting machines has not been widely used in Indonesia. Most local farmers have been using drum machines for a long time to roast coffee beans.

That is why fluidized roasting machine is not too popular among the wider public. Coffee roasting in the market generally uses the drum model which process is greatly dependent on the role and expertise of the roaster/operator. This innovation features a fluidized roaster which stirs and heats the coffee with hot compressed air, for easy control of the roast temperature, with perfect stirring or fluidized coffee beans. The roasting machine is equipped with an automatic pre-drying and cooling (tempering) process, where hot air (for drying) and cold air (for tempering) can be flowed into the roasting chamber automatically for an adjustable time.

Gigih added that the obstacle why it is not widely used in Indonesia is the difficulty in introducing this machine to the public. “We first set up a business unit under the profit-sharing scheme for coffee farmers in the village, with an initial agreement of 70% for farmers, 30% for coffee activists. It was the time when many farmers started to be interested in this machine,” he explained. “In addition, we also join the coffee community, in WA Groups, Facebook or exhibitions to introduce this fluidized machine further.” he added.

The partner of this research was initially the Regional Technology and Science (Iptekda) Office of West Sulawesi in collaboration with BPPT in 1999. All the funds were funded by the local government and carried out by PTA OR PPT BRIN. When coffee began to become a trend, the Central Java Government filed a request for research collaboration through the Balitbang project. There were four units that have been designed for engines with a capacity of five kilograms.

In 2005 this research joined the Research Incentive of National Innovation System (Insinas) program to design a 300 gr engine with electric power. In the following year, this research received funds from the research and technology program through the DPTM (Dissemination of  Community Technology Products) worth IDR110 million in which the research was only carried out by PTA OR PPT BRIN.

The machine made in this study with a capacity of two kilograms, was commissioned for the first time in Temanggung, and was successful. This was the turning point, as the machine was assigned to the right person who gave a lot of input for future machine improvement. “Eventually, the public knew this machine well and there was a request to make a 3 kg capacity machine which we finally developed for the needs of the coffee farmers there,” he explained.

Aside from Temanggung, this fluidization machine has been applied in Wonosobo, Malang, Banyuwangi, Aceh to West Sulawesi. In the future, this fluidized coffee roasting machine will be tried by adding an automatic gas control module for the burner so that the machine can perform power mapping during the roasting process. It is hoped that this tool can be a sample to be developed further and open up business opportunities for SMEs. (ir, sj/ ed: drs)