AA is the highest grade on the scale with a screen size of 7.2 millimeters. (Approx. 18/64 of an inch and often referred to as a screen size of 18). This grade of coffee often receives a higher price than other grades. This is a Premium grade. Kenya’s premium grade AA of coffee, is a measure of the bean size, weight and shape of the bean. Size is important because bigger beans mean
more aroma and flavor – the two qualities that are of the utmost importance to coffee drinkers. Bigger coffee beans are perceived to produce better quality coffee, all other factors remaining the same.