Efficient Sorting Solution: Testing a Small-Scale Coffee Bean Sorter for Coffee Farmers in Tabanan, Bali

This project is implemented by Yayasan Kopernik on behalf of our partner who provided grant funding for this project.

We are testing a small-scale coffee bean sorter to reduce time needed for sorting and improving size accuracy with smallholder coffee farmers in Tabanan, Bali.

Project Type

  • Experimentation
  • Product Development and Testing


Coffee farmers in Pupuan, Tabanan, Bali are currently sorting their green coffee beans inefficiently. They manually separate individual beans, which is time-consuming, by distinguishing only whole beans from defective* ones and not by size.

Not only is this process time-consuming, but coffee farmers are also missing out on the opportunity to increase their income due to this inefficient sorting process. Buyers often request specific bean sizes, as size can impact the taste and flavor of the coffee. For instance, artisan buyers, who are willing to pay premium prices, prefer coffee sorted by size because uniform beans result in a more consistent roast.

Although the farmers have a size-sorting machine provided by the local government (with a capacity of 20 kg/min), they no longer use the machine because it is too big and does not accurately sort beans by size.

*Defective beans include black beans, broken beans, and beans with holes. The small debris includes coffee husks, small sticks, and stones.


We will design, develop, and test small-scale coffee bean size sorter prototypes. The project will start with an in-house experiment to evaluate the accuracy of the size sorter prototypes in determining bean size. The prototype that demonstrates superior size sorting accuracy will be selected for the on-site experiment in Tabanan.

We will collaborate closely with the coffee farmers to assess the size sorter prototype and compare its performance with the current sorting practice. We will measure factors such as sorting time, size accuracy, and ease of use to determine the effectiveness of the prototype.


By utilizing the size sorter, coffee farmers are expected to decrease their sorting time and efficiently sort the beans into two size categories, while simultaneously removing defective beans and small debris.

Additionally, we will develop construction guidelines for the size sorter and make it available on our website for public use. The objective is to promote the widespread adoption and replication of this simple technology among smallholders across Indonesia.

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Solution & Project Implementation

Costs associated with the purchase of the solutions tested and project coordination


Monitoring & Evaluation

Costs associated with data collection, analysis and reporting


Administration Fee

Cost of transferring payments internationally, processing online donations (5%) and a contribution to Kopernik's operational costs (15%)


Total $13,349

This project is implemented by Yayasan Kopernik on behalf of our partner who provided grant funding for this project.