Dominion Blog

back-arrow Back to Blog List

Published 17 November 2017

Coffee Grading in Kenya

Kenya is one of those great African countries that is a joy to visit; not just because of the beautiful landscape but also the fantastic people you’ll meet on the road. What makes the country even more special to us is the fact that Kenya grows amazing coffee too.

 A Coffee Farm In Kenya

But what does it actually mean when we say that "we’ve got a great AA Kenyan" on the shelf?

If you’ve ever wondered (and who hasn’t 😉), keep on reading, because you will be amazed by how complex coffee grading is and what rigorous scrutiny a coffee bean has to go through to be considered “AA” material.


First off, coffee is harvested by the farmer and then sold to the local mill for processing. Coffees for sun drying go the dry mill and coffees for wet washing go to the – you guessed it – wet mill.

 Raised Beds At the Dry Mill

So, let’s have a look at the dry mill first.

After the drying process on the raised beds, coffee beans are hulled. That means that the “parchment”, a naturally occurring, papery skin that surrounds the  coffee bean, the mucilage, and other remaining material is removed. All that is left after hulling, is the pure coffee bean.

So, now that we’ve got all these wonderful and shiny coffee beans we have to grade them. Grading is a multi-step process that begins with simple separation by size classes. Kenya has five size classes:

  • AA (= biggest = best)
  • AB
  • C
  • PB*
  • E (= smallest = worst)

* PB = peaberries. Usually there are two coffee beans in one coffee cherry. Peaberries are special coffee beans that have only one coffee bean per cherry. These are usually smaller in size but often considered to be of superior quality, because the bean did not have to share the nutrients with another bean.

 Usually One Cherry Contains Two Beans

After this, coffees go through a density grader where beans are separated by how dense (mass over volume, not intelligence) they are.

Higher density coffee = better quality.

Coffees are classed into TT heavy and TT light.

(There’s also class T, which are those that failed the exam, but we're not going to show you those to not hurt their feelings).

After density grading, all AA (and AB) coffees are cupped and taste tested and then further divided into AA top, AA plus, AA FAQ plus, and AA FAQ (and of course AB top, AB plus, etc.).

So, if after all of this you, as a coffee bean, come out as a AA top, you are the best of the best. Sit back, put your legs up, relax, and enjoy your success.

But hold on. There's more …



Before we move on though, lets travel down the road and have a look at the wet mill and see what they’re up to:

 Washing Station in Kenya

After the washing process, but before the drying of the beans, the coffee (still wet) is also density tested into the following categories:

  • P1
  • P2
  • P3
  • P light
  • Bumi

Coffee At a Mill in Kenya 

Phew. After all that sorting and grading, the coffee can finally get sold to the auction house.

Then, after furious bidding and haggling, the coffee is bought by a trader who transfers the lots he purchased into his warehouse.

Guess what happens there … yeees. More grading.



First of all, the coffee goes through another round of density grading until finally, it has to face the evil eye of the optical grader.

This is a highly specialised machine where coffee beans are shot past a high speed video camera that analyses the picture of each individual bean for colour defects and sorts the bad ones out. A stream of compressed air is used to “nudge” the beans away into the discard box.

Oh yes, it's that fast!

So, all the coffee that made it through is then dried to proper moisture content for another fourteen to twenty-one days, re-bagged, and then exported, to finally make it to our roasting room - where we begin our own grading and sampling process.

Kenyan Coffee Bags Ready For Shipping

Find Us

City Espresso Bar:
Cnr Ogden and Stokes Street
Townsville City
QLD 4810

Roastery & Course Centre:
293 Ingham Road
QLD 4814

Contact Us

Coffee Cart - Book your Events &
Functions: Mel 0415 944 188

Espresso Bar: (07) 4724 0767

Roastery: 0451 231 431

General Enquiries

Course/Staff Training Enquiries

Opening Hours

Monday - Friday
6am - 3pm

Saturday & Sunday
6am - 12pm