RMACC Green Beans Sampling Methodology
Three hundred grams of properly hulled coffee beans should 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 a 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.
RMACC Arabica Green Beans Standards
CLASS 1 - 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 screen size indicated is tolerated. Specialty coffee must 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%.
CLASS 2 - 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%.
CLASS 3 - 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%.
CLASS 4 - Below standard Coffee Grade (4): 24-86 defects in 300 grams.
CLASS 5 - Off Grade Coffee (5): More than 86 defects in 300 grams.