Grades green beans by passing them through round-hole screens measured in 64ths of an inch, such as screen 16.
Screen sizing grades green coffee by bean size, passing it through circular holes measured in 64ths of an inch. Screen 16 is 16/64 of an inch. National grading systems use size differently, such as letter grades in Kenya, Tanzania and India, and Supremo and Excelso in Colombia. Size affects roasting behavior, but one source reports no significant extraction differences by size alone, and many small-bean coffees are top-scoring specialty lots.
How it worksCoffee is passed through circular holes measured in 64ths of an inch, so screen 16 corresponds to 16/64 of an inch.
History
Bigger beans have traditionally commanded higher prices. National grade systems differ, for example letter grades in Kenya, Tanzania and India, and Supremo and Excelso in Colombia.
Our notes on Screen Sizing are still being checked against their sources, so for now this page shows only the facts we can stand behind.
What can go wrong
- Size and cup quality are not simply linked: one source notes some of the best specialty coffees, such as Ethiopian lots, are small, and tests found no significant extraction difference by size.
A variant of
At the same stage
Sources · 2 Every sentence here was checked against a source we read. Taste notes are what guides describe, not promises about your bag. Last revised 2026-09-30.
- Coffee processing · Wikimedia Foundation
- Green Coffee Analytics Part II: Screen Size · Royal Coffee