Green Arabica Coffee Beans: Grades, Screen Sizes & Processing

How green Arabica is sized and graded (screen size, moisture, density and processing) and what each spec means for roasters.

Odisha CoffeeJuly 18, 20266 min read
Green Arabica Coffee Beans: Grades, Screen Sizes & Processing

Gray Cup roasts these Koraput lots to order, ships across India.

Screen size

Screen size is bean width measured in 1/64 inch. A "screen 17" bean passes a screen 18 sieve but not a 17.

| Screen | Rough size | Notes | |---|---|---| | 17–19 | large (AAA/A) | most uniform, roasts evenest | | 15–16 | medium (AA/A) | specialty workhorse | | 13–14 | small (B/BBB) | roasts faster, less evenly | | PB | round | peaberry, sized separately |

Uniformity matters more than absolute size, a tight screen range roasts predictably.

Moisture

10–12% is the target. Too dry (under 9%) and beans bake and taste flat; too wet (over 12.5%) and they mould and fade in storage. Ask for the reading.

Density

Higher-grown beans are denser and need more heat / a steeper roast curve. Density is often implied by altitude and grade but can be measured directly.

Processing (on top of size)

Screen size and grade describe the bean; washed / natural / honey / anaerobic describe the flavour. Two AAA lots can taste completely different.

Koraput green Arabica by grade

Reading a spec sheet

A good lot sheet lists: grade, screen size, moisture %, crop year, process, altitude, defect count, and a cupping note. If any of those is missing, ask before you buy.

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