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.