How do we distinguish the grades of coffee?

Grade 1: Specialty Grade Coffee Beans

Processed green beans contain no more than 5 full defects in 300 grams of coffee.

Sorted with a maximum of 5% above and 5% below specified screen size or range of screen size and have one or more distinctive attribute in the taste, acidity, body, or aroma.

It must be free of cup faults and taints, 0 quakers (unripe beans) and moisture content between 9-13%.

Grade 2: Premium Grade Coffee Beans

Processed green beans contain no more than 8 full defects in 300 grams of coffee.

Sorted with a maximum of 5% above and 5% below specified screen size or range of screen size and have one or more distinctive attribute in the taste, acidity, body, or aroma.

It must be free of cup faults and taints, maximum of 3 quakers (unripe beans) and moisture content between 9-13%.

Grade 3:

Processed green bean contains 9-23 full defects in 300 grams of coffee. It is sorted by 50% above screen 15 and less than 5% below screen 15. Maximum of 5 cracks (unripe beans).

Grade 4

Processed green bean contains 24-86 full defects in 300 grams of coffee.

Source: Green Coffee Classification System Poster from the Specialty Coffee Association of America.