Green Coffee Classification
Before any coffee is sold it is classified by the number of defects, screen size, and cup quality. The defect count is supposed to give a general idea of the quality of cup. Two green coffee classification methods have been described here. The SCAA Green Coffee Classification Method is excellent for specialty coffees, whereas the Brazilian Green Coffee Classification Method is more precise, but is also more time consuming.
SCAA Green Coffee Classification
The green coffee classification standard provided by the SCAA is an excellent method to classify coffee. It is superior over some systems in that it better accounts for the relationship between the defect and the cup quality. However, it leaves out a few of the important defects that can occur in the coffee (See the Brazilian Green Coffee Classification).
Three-hundred grams of properly hulled coffee should be using screens 14, 15, 16, 17, and 18. The coffee 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. I recommend that if the coffee is a high quality with few defects to 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 (1): No more than 5 full defects in 300 grams of coffee. No primary defects allowed. 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 taints. No quakers are permitted. Moisture content is between 9-13%.
Premium Grade (2): 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 Grade (3): 9-23 full defects in 300 grams. Must have 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 Standard Grade (4): 24-86 defects in 300 grams.
Off Grade (5): More than 86 defects in 300 grams.
| 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 Defect | 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 |
Brazil/ New York Method:
In the Brazilian method 300 grams of coffee is classified. The number of beans equivalent to one full defect is given below. For example, a set of three shells counts as one full defect. On the other hand, one large rock counts as five full defects. If a bean has more than one defect the highest defect is counted. For example, a bean that is black and damaged by insects counts as one full defect due to its black attribute. The table is split up into two since Brazilian legislation allows a maximum of 1% of foreign defects. After counting the number of defects, use the third chart to classify the type and its point rating.
| Intrinsic Defect | Number | Full Defects | ||
| Black Bean | 1 | 1 | ||
| Sour | 1 | 1 | ||
| Shells | 3 | 1 | ||
| Green | 5 | 1 | ||
| Broken | 5 | 1 | ||
| Insect Damage | 5 | 1 | ||
| Mal-formed | 5 | 1 |
| Foreign Defect | Number | Full Defects | ||
| Dried Cherry | 1 | 1 | ||
| Floater | 2 | 1 | ||
| Large Rock/Stick | 1 | 5 | ||
| Medium Rock/Stick | 1 | 2 | ||
| Small Rock/Stick | 1 | 1 | ||
| Large Skin/husk | 1 | 1 | ||
| Medium Skin/husk | 3 | 1 | ||
| Small Skin/husk | 5 | 1 |
| Defect | Type | Points | ||
| 4 | 2 | 100 | ||
| 4 | 2-5 | 95 | ||
| 5 | 2-10 | 90 | ||
| 6 | 2-15 | 85 | ||
| 7 | 2-20 | 80 | ||
| 8 | 2-25 2/3 | 75 | ||
| 9 | 2-30 | 70 | ||
| 10 | 2-35 | 65 | ||
| 11 | 2-40 | 60 | ||
| 11 | 2-45 | 55 | ||
| 12 | 3 | 50 | ||
| 13 | 3-5 | 45 | ||
| 15 | 3-5 | 40 | ||
| 17 | 3-15 | 35 | ||
| 18 | 3-20 | 30 | ||
| 19 | 3-25 3/4 | 25 | ||
| 20 | 3-30 | 20 | ||
| 22 | 3-35 | 15 | ||
| 23 | 3-40 | 10 | ||
| 25 | 3-45 | 5 | ||
| 26 | 4 | 0 | ||
| 28 | 4-5 | -5 | ||
| 30 | 4-10 | -10 | ||
| 32 | 4-15 | -15 | ||
| 34 | 4-20 | -20 | ||
| 36 | 4-25 4/5 | -25 | ||
| 38 | 4-30 | -30 | ||
| 40 | 4-35 | -35 | ||
| 42 | 4-35 | -35 | ||
| 44 | 4-40 | -40 |
| Defect | Type | Points | ||
| 4 | 2 | 100 | ||
| 4 | 2-5 | 95 | ||
| 5 | 2-10 | 90 | ||
| 6 | 2-15 | 85 | ||
| 7 | 2-20 | 80 | ||
| 8 | 2-25 2/3 | 75 | ||
| 9 | 2-30 | 70 | ||
| 10 | 2-35 | 65 | ||
| 11 | 2-40 | 60 | ||
| 11 | 2-45 | 55 | ||
| 12 | 3 | 50 | ||
| 13 | 3-5 | 45 | ||
| 15 | 3-5 | 40 | ||
| 17 | 3-15 | 35 | ||
| 18 | 3-20 | 30 | ||
| 19 | 3-25 3/4 | 25 | ||
| 20 | 3-30 | 20 | ||
| 22 | 3-35 | 15 | ||
| 23 | 3-40 | 10 | ||
| 25 | 3-45 | 5 | ||
| 26 | 4 | 0 | ||
| 28 | 4-5 | -5 | ||
| 30 | 4-10 | -10 | ||
| 32 | 4-15 | -15 | ||
| 34 | 4-20 | -20 | ||
| 36 | 4-25 4/5 | -25 | ||
| 38 | 4-30 | -30 | ||
| 40 | 4-35 | -35 | ||
| 42 | 4-35 | -35 | ||
| 44 | 4-40 | -40 |
