Kenyan coffee grading includes physical classifications such as AA, AB and PB. AA is associated with a larger bean-size category, AB with another common size selection, and PB with peaberries. The source also discusses categories involving smaller, lighter or broken material. These distinctions help explain sorting; they should not be read as a complete ranking of how every roasted coffee will taste.
A single producing lot can yield different physical selections. Sorting can help a roaster manage consistency, but size, shape and density are only part of the picture. Ask for the producer or factory, variety and processing information, together with the roaster’s assessment of the actual selection. Avoid treating an abbreviated grade as though it documented freshness, an award or a universal sensory score.
If comparing AA and AB, try to keep the producer, processing and roast as similar as possible. Brew at a consistent ratio and evaluate sweetness, acidity and finish without deciding the winner from the label. A good AB may suit your taste better than another AA from a different lot. This approach uses grades for what they explain while leaving cup quality to evidence about the particular coffee.
The conversation
A good question can make a better brew.