Coffee Glossary · Quality
Water Activity (aW)
A measure of how available a coffee's internal moisture is — thermodynamically free to migrate and support microbial life — expressed from 0 to 1. Two lots can share 11% moisture yet differ in water activity; the higher-aW lot ages faster and risks mold. Specialty buyers increasingly specify aW below ~0.60 alongside moisture percentage, because the pair together predicts shelf stability. Slow, even drying with rest periods produces low, stable water activity; rushed drying traps free moisture inside the bean.
Related terms
Moisture Content
The percentage of water in green coffee — the most fundamental export specification. The safe band is 10–12%:…
GrainPro / Hermetic Liners
Multi-layer plastic liner bags placed inside jute sacks to seal green coffee from oxygen and moisture — the…
Defects (Green Coffee)
Physical faults in green coffee counted under grading systems like the SCA's: category 1 (primary) defects —…
Bean Density
How much mass a coffee bean packs per volume — measured in g/L or judged by feel and appearance (tight,…
Cupping
Coffee's standardized tasting protocol: coarse-ground samples steeped in bowls under strict ratios and…
Grading (Green Coffee)
The classification of green coffee into commercial tiers by measurable criteria — screen size, defect count,…
Reading up before buying? Volcana Coffee exports SGS-inspected specialty Arabica and Fine Robusta from the Bolaven Plateau, Laos — and we're happy to walk new importers through every term on a real offer sheet.
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