Kenyan grading system
Every screen,
every score.
Kenyan coffee is graded after milling by bean size, density and shape. Grading happens at the dry mill; cup quality is confirmed at the Nairobi auction and by private-treaty samples. Here's what each grade means, how it's decided, and where it shines.
- Grades
- 6
- Screens
- 14–18
- Cupped to
- SCA
At a glance
The six Kenyan grades.
Screen size is measured in 1/64ths of an inch. Density and defect count decide the tier within each screen.
| Grade | Screen size | Density | Cup profile | Typical use |
|---|---|---|---|---|
| AA | 17/18 | Very dense | Bright acidity, complex fruit, blackcurrant, wine | Specialty single-origin, filter, flagship espresso |
| AB | 15/16 | Dense | Balanced acidity, sweet citrus, red berries | Specialty blends, filter, versatile espresso |
| PB | Peaberry | Very dense | Syrupy body, concentrated sweetness, tropical fruit | Single-origin espresso, small-batch filter |
| C | 14 and below | Medium | Clean, mild acidity, sweet | Commercial blends |
| TT | Lighter AA/AB | Light | Softer, cleaner | Value blends |
| T | Broken / thinner | Light | Mild, muted | Instant coffee, industrial blends |
How grading works
Four checks between mill and market.
Screening
Beans pass over graded mesh screens sized in 1/64ths of an inch. Larger screens (17, 18) become AA; 15, 16 become AB.
Density
Screen-matched beans are density-sorted on a gravity table. Denser beans hold more sugar and cup better — they keep the top grade.
Defect count
Samples are hand-picked for primary and secondary defects. The count sets the specialty tier long before the cup opens.
Cup score
Every lot is cupped in Nairobi to SCA protocol. Score, notes and freshness are published on the product page.
This week's harvest
From the shop
For roasters
Predictable roast behaviour.
A tight screen means an even roast. AA and PB lots hold heat well and reward a slow first crack; AB is your everyday workhorse for filter and espresso.
For cafés
A menu you can explain.
Grades give your baristas and your menu a shared vocabulary. AA on the guest bar, AB on the house blend, Peaberry as a monthly single-origin feature.
Ready to cup a specific grade?
Ask for samples of AA, AB or PB from the current harvest.