Physical Properties

Coffee as all agro-products possess characteristics related to its state, aspect or appearance such as weight, volume, size, shape, color, solubility, moisture content or texture. From seed to cup, the various physical characteristics of coffee in its different forms play an important role in the way it is processed.

Coffee is harvested when the berry outer skin color indicates that the appropriate maturity has been reached turning from green to burgundy. Flotation is used to physically separate defective cherries on the basis of density and to remove other foreign materials. Size, shape and color are used to grade beans after they have been dried to an even moisture content optimal for storage. Coffee beans have a porous, spongy texture and can easily be contaminated by fungi or pick up strong odors, and deteriorate rapidly if allowed to become too moist.

Coffee is a natural agro-product and therefore varies, but some typical physical properties of coffee are listed below:

Weight yields

Wet process: 550 Lb.’s fresh cherry –> 220 Lb.’s wet pergamino –> 120 Lb.’s dry pergamino –> 100 Lb.’s dry polished coffee;

Dry process: 550 Lb.’s fresh cherry –> 198 Lb.’s dry cherry –> 100 Lb.’s dry polished coffee;

When roasting coffee beans an average 16% loss in weight (shrink) occurs and an estimated increase in bean volume of 50% for a medium/light roast.

Moisture content

Fresh cherry: 50 %
Green bean: 12.5 %
Roasted coffee: below 5 % (depending on humidity and roast color)
Soluble powder: below 3 %

Bulk density

(lb./cu yard)

Red cherry 1345
Wet green beans 1345
Dry beans 673
Light roast beans 622
Dark roast beans 488
Coarse ground coffee 505
Fine ground coffee 673