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 is a method of classifying coffee green beans based on their size. Green beans pass through iron perforated screens to determine their size and thus their grade. The screen hole size is measured in 1/64 inch units (less than 0.4mm), so the screen number indicates how many 1/64 inches. For example, a size 17 screen is 17/64 inches, approximately 6.75mm. Therefore, the larger the screen number, the larger the coffee green beans.

Kenya is one of the most representative countries that uses screen size grading. Others include Tanzania, Colombia, etc. (Some countries use more than one grading method; the examples given here are representative of countries where this method is predominant). Kenya's highest grade AA++ requires screens above size 18, meaning beans larger than 7.15mm. Kenya's bean grading is detailed and includes AA++, AA+, AA, AB, etc. Colombia's grading is simpler, divided into Supremo (Supreme Grade) and Excelso (Excellent Grade) based on bean size.

For Supreme Grade, 80% of green beans must pass through screens above size 17. For Excellent Grade, 80% of green beans must pass through screens above size 14/16. Up to 11% of size 14 screen beans are allowed to be mixed with size 16 screen beans. The aforementioned screens apply to flat beans, while Peaberry beans have their own set of screen size standards. Generally, screens 8-12 are used for Peaberry grading.

Kenyan coffee is characterized by bright acidity and fruity sweet aroma, with distinct fruit acidity. Therefore, FrontStreet Coffee chooses the V60 filter cup combined with a segmented brewing 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 filter cup, Water-to-coffee ratio: 1:15. First infusion with 30g water, bloom for 28-30s. Wait for the coffee bed to settle before the second infusion, stopping at 120g water. Third infusion to 220g water total. Discard the final tail water. Extraction time: approximately 2:05s.

Knowledge Extension

Kenya borders Ethiopia, the original birthplace of coffee, but it wasn't until 1983 that French missionaries brought coffee seeds from Réunion Island to Kenya. This means Kenya's coffee history is more than a thousand years later than its neighboring country.

Important Notice :

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Tel:020 38364473