Some time ago we explained how to track coffee traceability in Kenya. Today we want to focus on the grading system of Kenyan coffee. You could find answers for the most frequently asked questions below.  

What is the difference between AA and AB? Does AA mean the best quality?

Fully washed coffee is the most popular one in Kenya. When coffee cherry arrives at the station, it is sorted before processing. In this case, only ripe red cherries are going to the cherry hopper.

Non-ripe cherries are sent to be dried in tarps and beds. They represent the low-quality natural coffee called Mbuni.  
 

Parchment classification:

Going back to ripe cherries: they pass through a special pulper and immediately after that they are classified by their density. There are 3 categories:  parchment 1 is the heaviest coffee, parchment 2 is the medium density coffee and P3 or P-Lights is the lightest one.

These 3 categories are fermented separately, washed and soaked separately and dried on different beds.  
 

Green Coffee Grading:

At the dry mill, coffee passes through a destoner, a huller, and a polishing machine and then finally it reaches graders. Graders are giant screens that sort beans by their sizes.  

It is important to notice, that grade is just a physical parameter, having nothing to see with coffee quality.

  • AA: Screen 18, (15-20% of the coffee production in Kenya).
  • AB: Screen 16.
  • C: Screen 15/10.
  • PB: Peaberry screen 12 (less than 10% of coffee production in Kenya).
  • E:  Elephants, screen 20: normally two seeds that are joined together in the same coffee cherry.
  • Cereza de café.

Furthermore, after grading, AA and AB coffee beans will be processed in gravity tables. These tables will detect the density one more time, so producers could define the low-density beans named TT.  The same happens with C grade coffee. The low-density C-coffee is called T grade. Normally it is a low-quality commercial product.

All coffee that arrives at dry mills should pass through the same procedures with the same screens for grading.  Does it mean that you can have AA grade coffee with P2 density category? Of course. There is no much AA/P2 coffee, but it happens.  And finally… Does it mean that AA coffee has better quality?

Let’s check out the auction report from February 06th: 

We should give a couple of comments:

1) Prices for AA are strongly deviated, which means the quality is also multifarious 

2) The lowest price for C grade coffee is higher than the lowest price for AB coffee. However, the maximum price for PB is higher than AB maximum price.   

We cannot assert that denser, heavier beans always taste better than C grade coffee.  AA grade coffee could taste harsh or fermented due processing issues, while in some cases PB and AB lots could taste better than bad AA.

Tags: Kenya