The Grading Green Coffee protocol is based on the SCAA Green Arabica Coffee Classification System (GACCS) version Spring 2000 and the SCAA Defect Handbook dated April 2, 2004. The Defect Handbook defines what are considered defects for the SCAA GACCS. If the coffee imperfection is not found in the Defect Handbook, it is not considered a defect for purposes of Evaluation.
- The SCAA GACCS determines the conversion or equivalent of single defects to full defects.
- The numbers of full defects are calculated on a basis of 350 grams of green coffee sample.
- Bean imperfections need to have the specific bean characteristics and criteria as they appear on the picture and physical description in the Defect Handbook to be considered a defect.
- A full defect can be a Category 1 (primary) or a Category 2 (secondary) defect.
- Specialty Grade samples must have zero Category 1 defects and no more than five Category 2 defects.
- A full defect is composed of one or more single defects depending on the impact each one has on the cup. Each defect is described in detail in the SCAA Defect Handbook.
- A full defect cannot be a fraction or a decimal. The correct way to count a defect is to consider defect numbers as integers rounding down instead of up.
- In the case that more than one defect is observed in a coffee bean, it shall be counted only as the defect that has the greatest impact on the quality of the cup, (the defects listed first in the SCAA Green Arabica Defect Handbook are considered to have the greatest impact on cup quality).
- The SCAA GACCS only defines two grades of coffee, Specialty Grade and Premium Grade. Other grades need to be defined as "Not classified by SCAA GACCS".
- In cases where several beans are considered to constitute a full defect (such as 5 broken beans = 1 full defect), the calculation showing the conversion of single defects to the correct amount of full defects must be shown.
- A bean is judged to be partial or full sour only if the orange/red color has fully penetrated the body of the bean, but not if the red color is only present on the silverskin (these are otherwise known as a "foxy" bean). A bean is deemed immature only if the silverskin is still firmly attached. To determine this, one may scratch it with a fingernail or rub the bean on a rough surface.
Green Grading Form
- This form may be downloaded from the SCAA store. It is to be filled out completely.
- Each grader (primary grader and verification grader) must write their name, date and the Sample identification code number in the space provided.
- Clearly specify the Grade of the coffee in the space provided on the form stating one of the following classifications:
- Specialty Grade
- Below Specialty Grade
- Show the calculation from individual defects to full defect equivalent.
- All final results are based on a 350 gram sample equivalent.
- Summarize the total number of Category 1 and Category 2 defects. This final result must be recorded on the upper right hand corner box of the grading form.
- Evaluation of the total number and type of defects will determine the grade (Specialty/ Below Specialty) of the sample. This result must appear in the box provided for GRADE.
- Each sample must be evaluated for color. Blue-Green, Bluish-Green and Green are the acceptable colors for Specialty Grade. A Greenish or inferior sample would not qualify.
- Each sample must also be evaluated for foreign odors. Graders need to stick their nose into the sample and inhale strongly to detect any foreign odor. Only samples that are completely free of foreign odors can qualify as Specialty Grade.
This document outlines the proper way to evaluate the color of green (unroasted) arabica coffee, as set forth by the Statistics & Standards Committee of the Specialty Coffee Association of America.
- Level work-surface (table) at least 2'L x 2'W (600 mm x 600 mm).
- 42-watt full-spectrum fluorescent tabletop fixture
- Circular bean dish
- Flat-black poster board / 2' x 2' (600 mm x 600 mm)
- Wooden straight-edge (ruler) approximately 12" (300 mm) long
Assessment should be performed in an area away from direct sunlight or other bright artificial illumination. The majority of the illumination on the sample should be provided by the table top light fixture for accurate rendering of color. The procedure requires about 180 grams of each green coffee to be evaluated.
- Align the black poster board along the forward edge of the table.
- Place the base of the light fixture along the edge of the poster board furthest away from the forward edge of the table.
- Adjust the fixture head so that it is perpendicular to the tabletop.
- Turn the light fixture on and at the brightest setting at least 5 minutes prior to use.
- Overfill the deep side of the bean dish with the green coffee to be evaluated. Use the flat side of the straight-edge to displace excess coffee and level the top surface so that it is even with the edge of the dish.
- Place the dish containing the sample on the poster board so that it is centered directly under the lamp head.
Note | If the sample is being compared to a reference sample, both the sample and the reference must have the same surface area and shape. Place both the sample and the reference so that they are side by side and equally positioned under the lamp head.
- Evaluate the sample(s) by adjusting your position so that your eyes are approximately 16" (400mm) above, and 16" (400 mm) away from the top surface of the sample(s).