Batch-type Coffee Roaster For Small-scale Coffee Business
Our love for coffee was basically brought about by the colonization of the country by the Spaniards more than two centuries ago when they turned our highlands into coffee plantations. They loved the perfect temperature and humidity plus the wet and dry tropical climate that made the cultivation of coffee well suited in the Philippines.
Growing coffee became such a profitable venture that for a while, the Philippines was one of the leading coffee-producing nations during the 19th century. But due to the coffee rust disease, such reputation was cut short. It was during this time that the Latin American countries battled it out and dominated the global coffee market.
In the Philippines, the coffee plantations are mostly in the mountains of Batangas, Bukidnon, Bunguet, Cavite, Kalinga, Apayao, Davao, and Claveria, Misamis Oriental. Approximately 60,000 to 80,000 families with roughly 120,000 hectares of productive land grow coffee, and these lands are both home and production unit for our local coffee growers.
BEAN ROASTING: THE KEY TO GOOD COFFEE
In a recent market study conducted by Ronald Mark G. Omafla of the Center for Food and Agribusiness at the University of Asia and the Pacific, he cited “coffee bean roasting as the critical factor” among major specialty coffee shop owners in the Philippines as “it is at this stage where the coffee bean releases its fullest flavor potential [and that] poorly roasted beans would yield poor-tasting coffee drink.”
For coffee connoisseurs and self-confessed aficionados, the difference always lies in how the coffee was prepared. Before, we were used to drinking instant coffees, simply because they are ubiquitous and are easy to prepare. But with the emergence of specialty coffee shops both foreign and local brands, even the tongue that was once used to drinking instant coffees are now craving for the “real coffee” the one which has a distinct rich taste and aroma, for it is made from coffee beans grown under ideal climates and prepared according to standards.
Before your rich coffee ends in your favorite cup and be enjoyed, it must first undergo several processes, one of which is roasting. It is the process of applying heat to transform the chemical and physical properties of green coffee beans into roasted coffee products. By applying heat, impurities in the beans are dried off for oxidizing products. This process is integral in producing a savory cup of coffee. Right amount of heat, right timing, in a uniform manner are required to achieve the desired flavor from the beans.
THE HEAT PROBLEM IN COFFEE ROASTING
Coffee shops in the Philippines continue to thrive by the numbers. But most of them are under franchising arrangements with big, foreign companies. These franchising companies can afford expensive roasters and other costly equipment, and an ordinary coffee producer cannot compete with them. There might be a few available coffee roasters for small-scale roasting but they may not turn out as efficient as the expensive ones, resulting in poor quality roasted beans.
Since coffee roasting involves proper heat application, common problems encountered include the uneven distribution of heat inside the roasting chamber and the lack of insulating materials which resulted in excessive heat loss. There is, therefore, a need for locally manufactured coffee roaster specifically for small-scale roasting purposes to boost the small-scale coffee producers in the country.
LOW-COST COFFEE ROASTER FOR SMALL-SCALE BUSINESS
Responding to this problem, Engr. Ruel M. Mojica of the Cavite State University (CaVSU) and Dr. Engelbert K. Peralta of the University of the Philippines Los Banos (UPLB) developed the first ever batch-type coffee roaster that can be used for small-scale roasting.
The coffee roaster was designed and fabricated at the College of Engineering and Agro-Industrial Technology in UPLB wherein the machine’s performance was also evaluated. The prototype coffee roaster is made up of six major parts: roasting chamber, outside drum, auger, heating plate, and burner. Parameters used during the evaluation included: auger speed, roasting time, valve opening, and fuel consumption.
Results of the performance evaluation showed that the machine had varying levels of auger speed. However, the varying speed had no significant effect on all the response variables. They also found an increase in roasting time which decreased the weight and moisture content of the roasted beans.
Varying the levels of valve opening was found to have significant effects on the weight and moisture content of the roasted beans as well as on the fuel consumption of the machine. On the other hand, no significant effect was noted on the roasting capacity of the machine.
In terms of sensory evaluation, coffee obtained using treatment combination of 40-rpm auger speed, 60-minute roasting time, and 3/4 open valve obtained the highest coffee rating of 86.1 percent.
Cost and return analysis showed that using this coffee roaster for small-scale custom work can be a profitable business with a potential net income of P63,451.49 annually.
The prototype model of the batch-type coffee roaster was first completed in 2005 but further innovations are being done to further improve its capability.
These are: evaluation of the machine using other coffee varieties (e.g. Arabica. Liberica); development of a microcontroller-based temperature control unit and software that would control the operation of the machine for a given period of time; evaluation of the machine using other crops (e.g. cacao, peanut); and use of Response Surface Methodology (RSM) to determine the optimum operating conditions of the machine.
