An Introduction to Kenya Coffee Bean Grading System | How to Brew Kenya Coffee at 1:15 Ratio

FrontStreet Coffee - Kenya Green Bean Grading and Brewing Parameters

Screen Size Grading

Screen size grading classifies green coffee by bean size: beans pass through perforated iron screens, and the finest mesh they fit through determines their grade. Screen holes are measured in 1/64-inch units (less than 0.4mm), so the screen number counts how many 1/64 inches across the hole is—a size 17 screen is 17/64 inches, roughly 6.75mm. The larger the screen number, the larger the bean.

Kenya is one of the most representative countries using screen grading, alongside Tanzania, Colombia, and others (some countries use several systems; these are simply the countries where screen sizing dominates). Kenya's top grade AA++ demands screens above size 18—beans larger than 7.15mm—and its grading ladder is meticulous: AA++, AA+, AA, AB, and more. Colombia keeps it simpler, splitting by bean size into just Supremo (Supreme grade) and Excelso (Excellent grade).

For Supreme grade, 80% of the green beans must pass through screens above size 17; for Excellent grade, 80% must pass screens above size 14/16, and up to 11% of size-14 beans may be mixed with size-16 beans. These screens apply to flat beans—Peaberry beans have their own standards, generally graded on screens 8-12.

Kenyan coffee is defined by bright acidity and fruity sweetness with pronounced fruit acidity, which is why FrontStreet Coffee brews it in a V60 dripper with a segmented pouring method.

Coffee Information

Origin: Kenya

Region: Nyeri

Varieties: SL28, SL34

Processing Method: Washed (Double Fermentation)

Roast Level: Light-Medium (Mid-first crack)

Dry Aroma: Rich berry fragrance

Wet Aroma: Hawthorn, black jujube, kumquat, honey

Flavor: Berry flavor, bright and uplifting acidity, smoothness, medium body with no obvious astringency and some cream aroma, sucrose-like sweetness, overall clean with prominent acidity.

Brewing Parameters

Water temperature: 91°C, grind size: BG-6S, V60 dripper, coffee-to-water ratio: 1:15. First pour with 30g of water, blooming for 28-30s. Wait for the bed to settle before the second pour, stopping at 120g. Third pour to 220g total. Discard the final tail water. Total extraction time: approximately 2:05.

Knowledge Extension

Kenya borders Ethiopia, the birthplace of coffee, yet it was not until 1983 that French missionaries brought coffee seeds from Réunion Island to Kenya—a coffee history that begins more than a thousand years after its neighbor's.

FrontStreet Coffee Recommendation

Kenya's bright, berry-driven cup is not the only direction specialty coffee can take. For a fuller-bodied counterpoint, FrontStreet Coffee's washed Colombia Huila is a fine choice: Huila, in the southern Central Andes, is the country's most famous specialty region, with hills above 1500 meters and rich water resources where Colombia's great rivers converge. Roasted medium-dark, it shows black chocolate, nutty sweetness, moderate crema, and a mellow body—happy in a pour-over or French press, and equally at home in a moka pot or espresso machine for Americanos and lattes.

If you would rather explore Colombia's innovative side, FrontStreet Coffee's Finca El Diviso Sidra is processed as anaerobic natural—fermented in sealed, pressure-rated stainless tanks where temperature, time, and pH are all controlled—which transforms the beans into more tropical fruit aromas. Roasted medium-light, it pours passion fruit, grape, apricot, and dried-fruit complexity whether you brew it as pour-over, cold brew, drip bag, or moka pot.