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Sorting the Great from the Good: Grading, Milling, and Exporting Specialty Coffee
Once parchment coffee is dried and rested, it’s ready for dry milling. This is the final transformation step before export—where parchment becomes green coffee, and quality control reaches a new level of precision. Understanding the science and logistics behind grading, milling, and exporting specialty coffee helps you become a more informed roaster and a smarter buyer.
Dry Milling — More Than Just Hulling
Dry milling involves hulling, size grading, density sorting, color sorting, and final bagging. It’s the stage where uniformity, defect control, and physical integrity are verified. At Nordic Approach, we conduct multiple green coffee analyses—checking moisture (ideally 9–11%), water activity (targeting 0.40 to 0.60), and defect counts following international standards for specialty coffee.
Why Green Grading Matters
Green grading bridges the gap between post-harvest processing and cupping. It reveals whether coffee was carefully harvested, sorted, dried, and handled. While roasting and brewing can enhance a coffee’s potential, no technique can fix a fundamentally flawed green. Defects can cause off-flavors, uneven roasting, or a complete breakdown in cup quality. Screen size affects roast consistency and appearance, but context is key. Each producing country has its own grading system, so we use Colombia and Kenya as examples. From Ethiopia to Honduras to Indonesia, understanding local grading standards is essential for sourcing high-quality coffee.
Screen Size Grading
Screen size is measured in 1/64ths of an inch. In Colombia, coffee is exported as Excelso or Supremo. Supremo refers to beans of screen 17 and above, while Excelso includes 14–17. Our standard is often screen 15 up, maximizing yield and financial return without compromising cup quality.
In Kenya, grading is more precise:
- AA: Screen 17/18
- AB: Screen 15/16
- PB: Peaberry
- C: Below screen 14 (not purchased)
We participate in pre-auction cuppings to select lots based on both screen size and flavor. High-scoring AA, AB, and PB lots can exceed 87–90+, offering both consistent and unique flavor profiles.
Defect Grading
Defects are classified into primary and secondary:
- Primary: Full black beans, full sour, fungus-damaged, foreign matter—any of these can heavily penalize a lot.
- Secondary: Broken, chipped, immature, partial black, parchment fragments—tolerated to a degree but still affecting cup quality.
According to SCA green grading protocol, a 350g sample must have no primary defects and very few secondary defects to qualify as specialty. We track defect trends at the lot level to trace quality issues back to harvest or processing decisions.
Final Checks and Export
After milling, pre-shipment cuppings ensure the coffee’s quality hasn’t changed during hulling or bagging. Coffees are packed in 60–70 kg jute bags with GrainPro liners or vacuum-sealed bags to protect moisture and prevent contamination. Containers are inspected, sealed, and tracked to local ports, such as Djibouti, Mombasa, or Dar Es Salaam.
Our quality control isn’t just a pass/fail check. We work with producers to continuously improve quality through cupping feedback, fermentation trials, and selective separation of high-scoring microlots.
By understanding the science, grading protocols, and export logistics behind specialty coffee, you become a better buyer, a more informed roaster, and a stronger partner in the global coffee supply chain.
Here you can read the first part of the article series about coffee processing&grading written by our Co-Founder and CEO Morten.
