The intent of grading green coffee bean is to classify its quality based on standardised measures. The better the quality, the higher the price for the coffee at the market, and the better it tastes! One of the challenges of understanding coffee grading is that, while the measures of quality may be standardised in the region that the coffee was grown and produced, there is no uniform way of grading coffee at a global level.
While there is no universal grading system for coffee beans, very generally speaking the grading of green coffee is based on the following sorts of criteria:
There is a correlation between the altitude and the density of the coffee bean, both being good indicators of coffee quality. The higher the elevation the coffee cherry is grown at, the slower the coffee tree will grow. The longer the fruit takes to grow, the denser the bean will be.
This guide is by no means a definitive explanation of all of the coffee grading’s used throughout the individual coffee growing regions, but it will provide you with some examples, including the terms you are likely to find on this site.
Countries of Central and South America generally confirm to a grading scale based primarily on bean hardness and altitude.
SHB (Strictly Hard Bean) coffees were grown above 1350 metres or 4500ft above sea level.
SHG (Strictly High Grown), same as SHB.
HB or HG (Hard Bean or High Grown) coffees were grown between 1200 and 1350 metres (4000 – 4500ft) above sea level.
EP (European Processed/Preparation) means that the green beans are sorted by hand to remove any beans which don’t meet standards, or any other foreign material.
Just to confuse things, Costa Rica has its own hardness grading scale. Costa Rican SHB is for beans grown above 3900ft. They then use additional grades of GHB (Good Hard Bean) for beans grown between 3300ft and 3900ft, and MHB (Medium Hard Bean) for the lower level elevations of 1600ft to 3000ft (around 500 to 1000 metres above sea level).
The grading in Kenya focuses on a combination of bean size as well as elevation. Bean size is the primary grading characteristic in Kenya.
Kenya AA is grown at elevations above 2000 metres or 6600ft above sea level. To be AA grade coffee means the beans also require a screen size of 18 or higher, or the equivalent of 7.2mm. These are the largest beans.
Kenya AB is a combination of ‘A’ beans and the slightly smaller ‘B’ coffee beans, with a screen size of 17, which equates to 6.8mm. This means the coffee is grown above 1500m, and includes coffee grown at the AA altitude.
Kenya PB is a Peaberry bean. In a ‘normal’ coffee cherry there will be two beans. In the case of a peaberry, the second bean ceases to grow and the remaining bean grows independently and becomes a ‘Peaberry’. Peaberry is not a true grade, rather it is a growth abnormality, and can occur in any coffee varietal. Peaberry tends to attract a high price because they are a rarity and there is a belief that their taste can be superior.