Classification

This Fine Robusta green grading protocol is based on the UCDA Fine Robusta coffee classification system and corresponding handbook. Any coffee imperfection not found in the classification handbook, shall not considered a defect for purposes of evaluation.

Principles

  • Imperfections are recognized as either Primary (Category 1) defects or Secondary (Category 2) defects
  • Only full equivalent defects are used when determining the grade of green coffee, as calculated using the Table of Equivalent Defects found in this document
  • The number of imperfect beans identified for each calculation of equivalent full defects must be recorded
  • Fine Robusta samples must have zero (0) Category 1 full defects and no more than five (5) Category 2 full defects
  • Premium Robusta samples must have no more than eight (8) combined Category 1 and Category 2 full defects
  • Grading requires a 350g green coffee sample
  • Imperfections must appear similar to and meet the written criteria shown in the Fine Robusta defect handbook in order to be classified a defect
  • Defect count must be recorded in whole numbers; fractional number or decimals are not acceptable
  • In beans containing more than more than one observed imperfection, only the more severe by Category, then Equivalent Defect shall be recorded

Green Grading Form

Proper use of the Green Grading Form requires each grader to:

  1. Write his or her name, date and the sample identification code number in the field provided
  2. Clearly specify a grade of the coffee where provided on the form stating one of the following:
    • Fine Robusta
    • Premium Robusta
    • Off Grade
  3. Show all calculations used to determine the number of Equivalent Defects
  4. Identify the total number of Category 1 and Category 2 defects in the provided fields
  5. Evaluate and categorize the color of each sample as blue, blue-green, green, greenish, yellow-green, pale yellow, yellowish or brown.
  6. Evaluate each sample for foreign odor

Green Coffee Color Assessment

Assessment should be performed in an area away from direct sunlight or other bright artificial illumination. A tabletop light fixture should provide the light projected on each sample. The procedure requires a minimum of 180g from each 350g sample.

Required Equipment

  • Level work-surface (table) at least 2’L x 2’W (600 mm x 600 mm)
  • 42-watt full-spectrum fluorescent tabletop fixture
  • Coffee bean tray
  • Flat-black poster board / 2′ x 2′ (600 mm x 600 mm)
  • Wooden straight-edge (ruler) approximately 12″ (300 mm) long
  • 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 (ruler) 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

Procedure

Note: If the sample is being compared to a second 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).