The quality in coffee, is very much affected by the chemical composition of the green bean, which is directly affected by its pre and post harvest processing conditions (such as variety, climate, soil, altitude, process, storage, etc.). How we measure quality includes: bean size and shape, crop year, number of defective beans, cup quality and moisture, density, water activity.
What is moisture? Moisture content is the amount of water (in the form of vapour) in a sample, given as a percentage of the sample's original weight. In coffee, there is no exact standard for an ideal moisture content, but a generally accepted range goes between 10-12%, with some important exceptions like Sumatra being closer to 12.5%; And Ethiopia and Kenya being closer to 9,5%.