How to Brew Kenyan Coffee Beans Introduction to Kenyan AA Coffee Bean Varieties Flavor Characteristics

Kenyan coffee has long captivated coffee enthusiasts with its rich fruit acidity and full-bodied flavor. Many coffee lovers visit FrontStreet Coffee for single-origin coffee, and when they want something acidic but prefer not to drink Ethiopian coffee beans, Kenyan coffee beans prove to be an excellent choice. When discussing Kenyan coffee, Kenya AA coffee beans inevitably come to mind. What exactly does AA mean? In this article, FrontStreet Coffee will explore what Kenya AA coffee beans are.

Coffee Growing Regions

Located in eastern Africa, with the equator crossing through its central region and the Great Rift Valley extending north to south, Kenya borders Somalia to the east, Tanzania to the south, Uganda to the west, and Ethiopia and Sudan to the north, while its southeast faces the Indian Ocean. The country features numerous highlands with an average elevation of 1,500 meters. Mount Kirinyaga (Mount Kenya) in central Kenya reaches 5,199 meters with snow-capped peaks, making it the second-highest mountain in Africa. Kenyan coffee beans possess wonderfully delightful and satisfying aromas, balanced and pleasant acidity, uniform particles, and excellent fruity flavors. FrontStreet Coffee has compared Kenyan coffee beans with those from neighboring Ethiopia and found that while both emphasize fruity acidity, they present completely different characteristics—Kenyan acidity is intense and full-bodied, while Ethiopian acidity is gentle and bright. For those trying African coffee beans for the first time, FrontStreet Coffee suggests starting with Ethiopian coffee beans before gradually transitioning to Kenyan coffee beans.

Kenyan coffee growing regions are mainly distributed in the central and western parts, including Thika, Kirinyaga, Mt. Kenya West, Nyeri, Kiambu, and Muranga. The harvest periods for these six major regions occur from October to December (main season) and from June to August (secondary season).

Among these, Thika and Kirinyaga best represent the flavor characteristics of African growing regions.

Thika

Thika is a small town located near Nairobi, the capital of Kenya. There are many coffee fields around Nairobi, and although Thika is an industrial town, it is surrounded by agriculture and waterfalls. The Thika region has approximately 2,000 farmers. The cultivation history of Kenyan Thika coffee dates back to the late nineteenth century, when coffee varieties were introduced from the northern neighboring country Ethiopia. After variety improvements, common varieties now include Bourbon, Kents (SL34, SL28), Typica, and Ruiru 11. Currently, about 90% of coffee planted consists of SL34 and SL28. The new variety Batian, released in 2007, has not yet been widely cultivated. This region's flavor features bright fruit acidity, full-bodied berry juice notes, and honey-like sweetness. Elevation: 1,550-1,750 meters. Varieties: SL-28, SL-34.

Kirinyaga

The Kirinyaga region is situated on the slopes of Mount Kenya, adjacent to the Nyeri region, and is world-renowned for producing coffee with intense flavors, rich layers, and robust mouthfeel. Together with the Nyeri region, it is recognized as one of Kenya's two finest coffee-producing areas. Most producers in this region are small-scale coffee farmers who join cooperatives. These cooperatives play a unifying role by providing washing stations where coffee farmers deliver their coffee cherries for processing. This region's flavor features bright fruit acidity with moderate oiliness and delicate sweetness. Elevation: 1,300-1,900 meters. Varieties: SL-28, SL-34, Ruiru 11, Batian.

Nyeri

Located in central Kenya, Nyeri is home to the dormant volcanic Mount Kenya. The region's red soil nurtures Kenya's finest coffee. Agriculture is extremely important here, with coffee being the primary crop. Cooperatives composed of smallholders are more common than large estates. This region has two harvest seasons, but coffee from the main season typically offers higher quality. This region features bright berry juice notes, complemented by citrus and subtle floral aromas. The coffee beans grown here have made Kenyan coffee famous worldwide. Elevation: 1,200-2,300 meters. Varieties: SL-28, SL-34, Ruiru 11, Batian.

Coffee Bean Varieties

Kenya primarily grows SL28, SL34, and Ruiru 11.

SL28 and SL34: These are genetic variants. They constitute the vast majority of Kenya's high-quality coffee production, though these varieties are susceptible to leaf rust disease. SL34 has French missionary, Bourbon, and more Typica lineage. With its copper-colored leaves and broad bean shape, it offers wonderful sweetness, balance, and complex, varied flavors, along with prominent citrus and plum characteristics.

Ruiru 11: In 1985, during a global rust disease outbreak, Kenya developed this hybrid variety that emphasizes yield over quality. However, its flavor quality is far inferior to the previous SL28 and SL34, and it hasn't gained traction in the specialty coffee industry. Nevertheless, many specialty coffee suppliers, even those importing premium beans, mix this hybrid variety into their blends to reduce costs.

Kenya AA Coffee Bean Classification

As mentioned earlier regarding Kenya AA coffee beans, AA is actually a classification of Kenyan coffee beans. Next, let's examine how Kenya classifies its coffee beans. Kenyan coffee classification is primarily based on bean size and is typically divided into eight grades:

• AA Plus (AA+): AA-grade beans with exceptionally excellent cup quality (flavor, mouthfeel).
• AA: Bean size (Screen Size) 17-18.
• AB: Bean size (Screen Size) 15-16, accounting for the majority of production.
• C: Bean size (Screen Size) smaller than AB.
• TT: Lighter-weight beans blown out by air classifiers from AA and AB grade beans.
• T: Lighter-weight beans blown out by air classifiers from C grade beans.
• E Elephant Bean: Large mutated beans where two beans merge, also known as elephant ear beans.
• PB Peaberry: Classified by shape, unrelated to flavor or weight.

Coffee Bean Processing Methods

The traditional washed processing method is not complicated: floating selection → pulping → fermentation → washing → drying → hulling → packaging. However, its implementation requires an adequate water supply and, as it heavily relies on mechanical assistance, producers using this method must have sufficient funds to invest in equipment. The rise of the washed method coincided with early American plantations established by capital—that is, those with sufficient operating funds, combined with various inventions like pulpers and hullers that emerged to meet contemporary needs—thus driving the widespread adoption of the washed method throughout the Americas.

Originally, the wet processing method involved washing the fermented coffee beans once with clean water to remove the mucilage before sending them directly to drying grounds for drying and packaging. However, in Kenya, coffee that has been washed once is re-soaked in a pool of clean water, then taken out and washed again before being sent to the drying grounds for dehydration.

Kenya initially changed from conventional washing to "double soaking" not to pursue flavor but due to insufficient local drying space. Kenya follows a typical cooperative operational model common in Africa. During harvest seasons, small farmers deliver freshly picked cherries to processing plants throughout the day. The pulping and fermentation process is relatively simple and time-efficient, but drying each batch of fermented beans requires at least 5 to 7 days. Sometimes, when the volume to be processed is too large, there isn't enough space to dry the washed beans. Therefore, people had to pour the wet beans back into the pools to let them "cool down" and prevent spoilage or contamination until the drying grounds became available.

This double-soaked washed form is called "Double Washed," meaning double washed, and is also referred to as "Fully Washed" in producing regions. Since Kenya was the earliest region where this processing method became popular and implemented, this type of washing is also known as the "Kenyan Process" or Kenya processing method. Later, people discovered that this twice-fermented washed method, adapted to local conditions, not only facilitates stable quality control in production but also imparts coffee with richly layered fruity acidity flavors.

In addition to the two processing methods mentioned above by FrontStreet Coffee, the most representative Kenyan coffee processing is undoubtedly the K72 washed method. The washed process emphasizes control over fermentation time: first, a 24-hour washed fermentation is performed, then the removed mucilage is cleaned, followed by another 24-hour fermentation in clean water pools. Subsequently, residual components are cleaned again, and the beans are placed in tanks with clean water for a final 24-hour fermentation, totaling 72 hours. This process also imparts Kenyan coffee with bright, clean, high-quality fruity acidity. The Asalia coffee regularly offered by FrontStreet Coffee uses this washing technique, presenting acidity reminiscent of cherry tomatoes and plums when brewed.

Next, another 24-hour fermentation with clean water follows, then washing again. After repeating this cycle three times to reach 72 hours, it's called the Kenyan 72-hour fermentation washed processing method, abbreviated as [K72]. FrontStreet Coffee believes that compared to conventional washed processing, the K72 washed method further enhances the acidity and cleanliness of coffee beans.

FrontStreet Coffee: Kenya Asalia Coffee Beans

• Region: Kenya Thika
• Processing Station: Asali Honey Processing Station
• Elevation: 1,550-1,750 meters
• Grade: AA TOP
• Varieties: SL28, SL34
• Processing Method: Kenya 72-hour Washed

FrontStreet Coffee Roasting Recommendations

When roasting this Kenyan coffee bean, FrontStreet Coffee considered highlighting its rich fruity acidity and full-bodied berry juice notes, therefore adopting a light to medium roast level.

Yangjia 800N: Set roaster temperature to 200°C when loading beans, air damper at 3, heat at 160. Return temperature at 1'34", when roaster temperature reaches 147°C, reduce heat to 130, open air damper to 3.5. At this point, bean surface turns yellow, grassy aroma completely disappears, entering the dehydration stage. When temperature reaches 171°C, reduce heat to 80, keeping air damper unchanged.

At 8'28", ugly wrinkles and black spots appear on the bean surface, and the distinct toasted bread aroma clearly transitions to coffee aroma, which can be defined as the prelude to first crack. At this moment, listen carefully for the sound of first crack. At 8'52", first crack begins, adjust air damper to 5. After first crack, develop for 2'10", then unload at 191.6°C.

FrontStreet Coffee Cupping Report

FrontStreet Coffee Brewing Recommendations

Considering this bean is roasted using a light to medium approach, FrontStreet Coffee would use higher water temperature and a faster-flowing dripper, mainly to extract its bright acidic characteristics with high temperature while avoiding over-extraction caused by high temperatures, thus choosing the faster-flowing V60 dripper.

• Coffee-to-water ratio: 1:15
• Coffee dose: 15g
• Water temperature: 90°C~91°C
• Grind size: Fine sugar size (80% pass-through rate with #20 standard sieve)

First, pour 30g of water for a 30-second bloom, then pour 105g more (scale shows approximately 135g), completing the pour in about 1 minute. When the water level drops to 2/3 of the coffee bed, pour the remaining 120g (scale shows approximately 255g), completing the pour in about 1 minute and 45 seconds. Complete drip filtration at 2'10", remove the dripper, and finish extraction.

Brewing flavors: The entry presents plum and cherry tomato flavors, with intense, full-bodied acidity. The mid-section features prominent sweetness with juice-like qualities, while the aftertaste offers berry aromas and brown sugar sweetness, accompanied by green tea fragrance.

For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat official account: cafe_style). For more specialty coffee beans, please add FrontStreet Coffee's private WeChat account with ID: qjcoffeex

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