Performance of Disk Mill Type Mechanical Grinder for Size Reducing Process of Robusta Roasted Beans

Main Article Content

Sri Mulato
Sukrisno widyotomo
Hadi Karia Purwadaria


One of improtant steps in secondary coffee processing that influence on final product quality such as consistency and uniformity is milling process. Usually, Indonesian smallholder used "lumpang" for milling coffee roasted beans to coffee powder product which caused the final product not uniformed and consistent, and low productivity. Milling process of coffee roasted beans can be done by disk mill type mechanical grinder which is used by smallholder for milling several cereals. Indonesian Coffee and Cocoa Research Institute have developed disk mill type grinding machine for milling coffee roasted beans. Objective of this research is to find performance of disk mill type grinding machine for size reducing process of Robusta roasted beans from several size dried beans and roasting level treatments. Robusta dried beans which are taken from dry processing method have 13—14% moisture content (wet basis), 680—685 kg/m3 density, and classified in 3 sizes level. The result showed that the disk mill type of grinding machine could be used for milling Robusta roasted beans. Machine hascapacity 31—54 kg/h on 5,310—5,610 rpm axle rotation and depend on roasting level. Other technical parameters were 91—98% process efficientcy, 19—31 ml/ kg fuel consumption, 0.3—1% slips, 50—55% particles had diameter less than 230 mesh and 38—44% particles had diameter bigger than 100 mesh, 32—38% lightness was increased, 0.6—12.6% density was decreased, and solubility of coffee powder between 28—30%. Cost milling process per kilogram of Robusta roasted beans which light roast on capacity 30 kg/hour was Rp362.9. Key words : Coffee roasted, Robusta, disk mill, mechanical grinder, size reduction.

Article Details

How to Cite
Mulato, S., widyotomo, S., & Karia Purwadaria, H. (2006). Performance of Disk Mill Type Mechanical Grinder for Size Reducing Process of Robusta Roasted Beans. Pelita Perkebunan (a Coffee and Cocoa Research Journal), 23(3).
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Authors who publish with this journal agree to the following terms:

    1. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
    1. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
    1. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).