This grade is a combination of two grades A and B A- 6.80mmscreen, B-6.20mm screen. AB is regarded as a representative of the other grades in a consignment and usually there is more coffee of his grade than of other grades in a consignment. It is also a popular grade which fetches good prices. On average, 30% of Kenyan coffee is assigned this grade, passes through screen No. 18, retained in No. 16.