The green coffee beans classification standard provided by the SCAA is an excellent method to compare coffee beans. It is superior over some systems in that it better accounts for the relationship between the defective coffee beans and the cup quality. However, it leaves out a few of the important coffee defects that can occur in coffee (See the Brazilian green coffee beans classification method).

Three-hundred grams of properly hulled coffee beans should be sorted using screens 14, 15, 16, 17, and 18. The coffee beans remaining in each screen is weighed and the percentage is recorded. Since classifying 300 grams of coffee is very time consuming, 100 grams of coffee is typically used. If you are dealing with a high grade coffee with only a few defects, use 300 grams. If the coffee is of a lower quality with many defects, 100 grams will often suffice in a correct classification as either Below Standard Grade or Off Grade. The coffees then must be roasted and cupped to evaluate cup characteristics.

Specialty Grade Green Coffee (1): Specialty green coffee beans have no more than 5 full defects in 300 grams of coffee. No primary defects are allowed. A maximum of 5% above or below screen size indicated is tolerated. Specialty coffee m ust possess at least one distinctive attribute in the body, flavor, aroma, or acidity. Must be free of faults and taints. No quakers are permitted. Moisture content is between 9-13%.

Premium Coffee Grade (2): Premium coffee must have no more than 8 full defects in 300 grams. Primary defects are permitted. A maximum of 5% above or below screen size indicated is tolerated. Must possess at least one distinctive attribute in the body, flavor, aroma, or acidity. Must be free of faults and may contain only 3 quakers. Moisture content is between 9-13%.

Exchange Coffee Grade (3): Exchange grade coffee must have no more than 9-23 full defects in 300 grams. It must be 50% by weight above screen size 15 with no more than 5% of screen size below 14. No cup faults are permitted and a maximum of 5 quakers are allowed. Moisture content is between 9-13%.

Below is a chart for grading coffee beans. It is based on the primary defect and the number of defective coffee beans:

Primary Defects

Primary Defect	Number of occurrences equal to one full defect.
Full Black	1
Full Sour	1
Pod/Cherry	1
Large Stones	2
Medium Stones	5
Large Sticks	2
Medium Sticks	5

Secondary Defects

Secondary Defects	Number of occurrences equal to one full defect
Parchment	2-3
Hull/Husk	2-3
Broken/Chipped	5
Insect Damage	2-5
Partial Black	2-3
Partial Sour	2-3
Floater	5
Shell	5
Small Stones	1
Small sticks	1
Water Damage	2-5

For more information about green coffee grading, visit Teaandcoffee.net.