Kenyan coffee is famous for its intense, full-bodied fruity acidity, forming a sharp contrast with the soft, translucent character of neighboring Ethiopia. This article systematically reviews the development history, growing conditions, main producing regions, variety structure, grading system, and trading models of Kenyan coffee, and explains in detail the definitions and differences among grades such as E, AA, AB, and PB. At the same time, Front Street Coffee combines roasting and cupping experience with multiple Kenyan beans to share the flavor performance and pour-over suggestions for two beans, Asalia and Thaithini Estate PB, helping you gain a comprehensive understanding of Kenya's coffee quality system.
Kenyan coffee beans have a delightful aroma, balanced acidity, uniform bean size, and excellent fruity flavors. Front Street has previously compared coffee beans from Kenya with those from neighboring Ethiopia and found that although both regions are dominated by fruity acidity, the expression is completely different—Kenya's acidity is more intense and full-bodied, while Ethiopia's acidity tends toward softness and translucence.
The Development History of Kenyan Coffee
Kenya is located in East Africa, adjacent to Ethiopia. Compared with Ethiopia's long coffee history, Kenya did not introduce coffee until nearly the 20th century. When coffee was introduced, Kenya was still a British colony. To earn foreign exchange, the colonial government vigorously promoted coffee cultivation in Kenya, and the harvested coffee beans were shipped to London for export sale. In 1922, Kenya established the Scott Agricultural Laboratories (Scott Labs, from which SL28 and SL34 get their names), specializing in coffee cultivation research. Over the following decade or so, the laboratory selected SL28 and SL34 from 42 coffee varieties as suitable for local growing regions, laying a solid foundation for the coffee industry. Today, these two varieties account for about 90% of Kenya's planted area.
The Kenyan government attaches great importance to coffee sales. In 1931, the Kenya Planters Co-operative Union and the Kenya National Coffee Board were established to guide the development of the coffee industry from both the private and national levels. In 1937, the Nairobi Coffee Exchange was established, and Kenya's coffee auction system was launched, allowing good coffee to obtain good prices and laying the foundation for coffee pricing. In 1938, the government issued a coffee grading system, namely the later well-known AA, AB, PB, etc., providing a basis for the quality of Kenyan coffee.
Kenyan Coffee Cultivation
Most Kenyan coffee is grown in the fertile, loose, acidic volcanic red soil of the highlands north and east of Nairobi. This region has abundant sunlight and good drainage, with elevations ranging from 1,400 to 2,000 meters. The higher the elevation, the greater the temperature difference between day and night, and Kenya's coffee maturation cycle is longer than in low-altitude regions, so the beans have higher density and more intense flavor.
Kenyan coffee usually flowers after rainfall, concentrated in March and April. Coffee cherries (fruit) mature from May to July, then mature again in September and October, allowing two harvests per year.
Kenyan Coffee Producing Regions
Kenyan coffee producing regions are mainly distributed in the central and western areas. The main central producing regions include Kiambu, Nyeri, Kirinyaga, Muranga, Embu, Machakos, Ruiru, and Thika; the western producing regions include Kisii and the Bungoma area located on Mt. Elgon.
FrontStreet Coffee regularly updates the coffee producing regions on its bean list, and Kenya is no exception. Last month, FrontStreet Coffee purchased a batch of Kenyan coffee beans from different producing regions. After roasting, cupping, pour-over, and other stages of tasting, it found that each producing region has a different style. Kiambu and Muranga show relatively bright and full-bodied acidity. Nyeri has bright citrus and floral aromas, slightly inferior to Ethiopia's Yirgacheffe, but with a full-bodied berry-like acidity. Kirinyaga's acidity is also on the bright and full-bodied side, accompanied by a delicate sweetness. Embu's acidity is not as full-bodied and intense as the previous regions, and its flavor tends more toward balance with a long finish. Machakos has outstanding acidity, a delicate mouthfeel, and a long aftertaste, gradually attracting the attention of coffee buyers. The biggest difference between Kisii and Bungoma and other producing regions is their prominent fruity sweetness, soft acidity, and nutty flavor.
Kenyan Coffee Cultivation Models
Kenyan coffee is composed of two major cultivation entities: large estates, namely more than 3,000 large farms, accounting for about 25% of Kenya's coffee planted area; the remaining 75% are agricultural cooperatives, composed of 270 cooperatives and a total of 700,000 smallholder farmers. In the 1960s, smallholder cooperatives began building shared processing plants, enabling them to harvest and process coffee like large estates. FrontStreet Coffee believes that this model allows coffee farmers to focus more on coffee cultivation and production. Ethiopia's main coffee cultivation model is also smallholder cooperatives. A batch of Yirgacheffe Konga cooperative coffee beans purchased by Front Street some time ago showed excellent floral and fruity aromas.
Kenyan Coffee Varieties
In Kenya, common coffee varieties include SL28, SL34, and Ruiru11. In 1922, Kenya established the Scott Agricultural Laboratories (Scott Labs) to engage in coffee cultivation research. Over the following decade or so, the laboratory bred SL28 and SL34 from 42 coffee varieties as suitable for local cultivation, giving the coffee industry a good start. Both SL28 and SL34 are varieties selected after multiple generations of breeding. SL28 belongs to the Bourbon genetic group and carries the bright profile and rich acidity of original Bourbon. SL34's lineage is closer to Typica, and its acidity is gentler than SL28's. At present, SL28 and SL34 account for 90% of Kenya's production, and South America is also actively introducing SL28 as a cultivated variety. The Asalia coffee that Front Street likes very much is precisely composed of these two varieties.
The birth of Ruiru11 stemmed from a global outbreak of coffee leaf rust. At that time, many Arabica varieties suffered from the disease. To avoid reduced coffee production, researchers developed the hybrid variety Ruiru11. It performs excellently in disease resistance, but its flavor quality is far inferior to SL28 and SL34.
Kenyan Coffee Grading System
Kenya classifies grades according to coffee bean size and cupping results. According to bean size, shape, and hardness, from high to low, they are E, AA or AA+, AB, C, PB, TT, T. E (Elephant bean): Here "E" stands for Elephant, but it is not the Maragogype elephant bean among coffee varieties. It is an abnormally developed bean in which two seeds intertwine with each other, forming a shape that "looks like one bean," and is essentially a defect. Usually, a fruit contains two seeds that fit face-to-face, so one side is flat, and they are called flat beans or mother beans. Grade E beans are two seeds that fuse and stick together during growth, becoming especially large. Grade E beans are about 18 screen size (one screen is 1/64 inch) or larger and are rare in number. AA: This grade is about 17 to 18 screen size (about 6.7 to 7.1 mm) and is the Kenyan coffee grade most people have heard of. In specialty coffee, this grade is usually called AA TOP, and it is also the bean most coffee shops promote. But AA does not mean the best; it only reflects bean size and cannot be equated with flavor.
FrontStreet Coffee Kenyan Thaithini Coffee Beans AA Grade
AB: Most coffee beans belong to this grade. It is called AB mainly because A's screen size is 6.80 mm and B's is 6.20 mm. These two sizes of coffee beans (Grade A and Grade B) are sold mixed together, so it is called AB, about 15 to 16 screen size (about 6.0 to 6.4 mm). FrontStreet Coffee Kenyan Asalia Coffee Beans AA TOP Grade C: Bean size is about 14 to 15 screen size (about 5.6 to 6.0 mm), smaller than Grade B. PB: Full name Peaberry, also called small round bean, or male bean. Compared with ordinary flat beans, PB is relatively rare, accounting for about 10% of all coffee beans. It comes from only one seed developing fully inside the fruit, thus producing a small, round bean. Some people especially prefer the flavor of PB, so it is sorted out and sold separately.
FrontStreet Coffee Kenyan Thaithini Coffee Beans PB Grade
TT: This type of coffee bean is light bean screened out from AA and AB by an airflow sorter. It is usually light in weight and does not meet hardness standards, and also contains broken and defective beans. T: Lighter beans screened from Grade C beans, mixed with broken beans, and even fragments of shattered beans. In addition, there are MH/ML grades: these coffee beans are not used for export. They are usually overripe beans that have fallen to the ground. Their quality is poor, accounting for about 7% of all coffee beans, and they are only supplied to Kenya's domestic market. For green beans of AA and AB grades, exporters have also established additional cupping grades (not officially recognized by the Kenyan state), from high to low: TOP, PLUS (+), FAQ. The Kenyan Asalia on FrontStreet Coffee's bean list reaches the TOP flavor level. However, as mentioned earlier, this is not an officially recognized grading system. Among the several Kenyan producing-region coffee beans purchased by FrontStreet Coffee, not every one carries a flavor grade, so there is no need to dwell too much on this point. Generally, reaching AA and AB grades already means the flavor is by default considered high quality.
FrontStreet Coffee Kenyan Asalia Coffee Beans AA TOP Grade
Kenyan Auction System
FrontStreet Coffee mentioned earlier that during colonial rule, local farmers did not gain much from coffee, which can be said to be a dark moment in the history of Kenyan coffee cultivation. In 1931, in order to help coffee farmers strive for better prices and income and no longer be constrained by distant traders, the government established the Kenya Planters Co-operative Union and the Kenya National Coffee Board and created an auction mechanism. In 1937, the Nairobi Coffee Exchange was established. By this time, the auction trading system had become more widespread and widely supported.
Most coffee beans are uniformly graded and inspected by the Coffee Board of Kenya and then sold at auction. The public auction system can be traced back to before 1934, and the auction uses an agent system. Kenya has 50 licensed agents, who send sample beans to their respective clients for cupping. Clients can entrust agents to bid at auction for the coffees they like. But this method seemed to encourage intermediary agents and eroded farmers' income. Therefore, in 2006 Kenya opened up 32 independent sales agents who can directly contact foreign coffee buyers without going through the auction. However, these all need to meet the Coffee Board of Kenya's standards for quality, storage, bank guarantees, and other aspects. The two systems operate in parallel. After several years of development, they have formed the most transparent auction distribution system. The better the quality of the coffee, the better the price it can obtain through cupping, making more cooperatives and estates willing to participate. FrontStreet Coffee also pays close attention to the coffee auction market, as this not only helps understand changes in the local coffee market, but the improvement of the auction mechanism ultimately benefits not only coffee farmers but also buyers from around the world.
Two Main Trading Models for Kenyan Coffee Beans ① Nairobi Coffee Exchange auction (central auction system), about 85% of coffee beans are traded through the auction system Since the auction system was established in the 1930s, the vast majority of Kenyan coffee has been traded in this way. Coffee auctions are held every Tuesday during the harvest season. It evolved from an "open outcry" auction system, in which each trader bids by pressing an electronic trigger. In this system, because agents compete with one another, prices for high-quality, highly sought-after coffee soar.
② Direct trade (often called the "second window"), only about 15% of coffee beans are traded through the direct trade model After 2006, the Kenyan government allowed farmers to trade directly with foreign buyers (such as roasters or importers), and a price different from the auction price could be agreed upon before or during harvest. Some exporters also buy coffee directly from relevant marketing agents or factories, using the previous week's auction price for a specific grade as a basis for negotiation. Direct trade allows farmers producing high-quality coffee to earn more income. When direct trade is not feasible, the coffee is then sold back through the exchange auction.
What Kenyan Coffee Beans Does Front Street Have?
After several rounds of tasting, FrontStreet Coffee ultimately selected only two or three coffees from the initial dozen or so coffee beans from different producing regions to put on the list. It is not that the other coffee beans are bad. FrontStreet Coffee's original intention is not to sell, but in this process to understand each coffee producing region, different varieties in the same producing region, different processing methods for the same variety, and to build a corresponding database, as well as comparisons among different producing regions. FrontStreet Coffee hopes to let more coffee lovers understand the world of coffee.
FrontStreet Coffee: Kenya Asalia Coffee Beans
Producing Region: Kenya Thika Region Asali Processing Plant
Altitude: 1550-1750m
Processing Method: Washed
Variety: SL28 & SL34
Flavor: Tomato, snow pear, smoked plum, yellow sugar, plum, cherry tomato
[Roasting Suggestion] The beans of this Front Street coffee are plump and round. In order to fully display its bright and mellow acidity, Front Street uses a light roast.
[Cupping Flavor]
[Front Street Pour-over Suggestion] The brewing parameters used by Front Street are: V60 dripper, water temperature 90°C, dose 15 g, coffee-to-water ratio 1:15, grind size like fine granulated sugar (80% passing through a Chinese standard No. 20 sieve). Here FrontStreet Coffee should mention one point: why should the grind be sifted before determining the grind size? This is actually the grind recommendation provided by the Specialty Coffee Association of America, SCA, for pour-over coffee. After extensive verification, FrontStreet Coffee found that brewing with different grind sizes produces clearly different results, and the grind size for each coffee bean is somewhat different. This is the significance of sifting. If there is no sifter at home, FrontStreet Coffee suggests judging by observing the flow rate: if the flow is too fast, the grind is coarse; if the flow is too slow, the grind is fine.
FrontStreet Coffee uses staged extraction: bloom with 30 g of water for 30 seconds, then pour in a small stream in circles until 125 g for the first stage. When the water level drops and is about to expose the coffee bed, continue pouring until 225 g and stop. When the water level drops and is about to expose the coffee bed, remove the dripper. The extraction time (starting from the beginning of blooming) is 2'00".
[Front Street Kenyan Asalia Coffee Bean Flavor] The wet aroma has ripe tomato and floral notes. On the palate there are flavors of cherry tomato and smoked plum. The acidity is bright, and the mouthfeel is clean and rich. The mid-palate has prominent sweetness with a juicy feel. The finish carries berry aroma and yellow sugar sweetness, along with green tea aroma.
FrontStreet Coffee: Kenya · Thaithini Estate PB Coffee Beans Producing Region: Kiambu Producing Region Estate: Thaithini Estate Altitude: 1680 meters Grade: PB Variety: SL28, SL34 & Ruiru Processing Method: Washed Processing
[Roasting Suggestion] FrontStreet Coffee uses a light roast. As mentioned earlier, Kenyan coffee beans overall have bright acidity as their main profile. To highlight this point, FrontStreet Coffee suggests making slight adjustments in the direction of a light roast.
[Cupping Flavor]
[Front Street Pour-over Suggestion] The brewing parameters used by Front Street are: V60 dripper, water temperature 90°C, dose 15 g, coffee-to-water ratio 1:15, grind size BG#5I (80% passing through a Chinese standard No. 20 sieve). Perhaps sharp-eyed readers will notice that FrontStreet Coffee's grind parameter for this Kenyan coffee bean is different from that of the other bean earlier. The grind size for each coffee bean varies because factors such as variety, altitude, processing method, and roasting differ. Therefore, when FrontStreet Coffee receives a newly roasted bean, it first sifts it once to determine the appropriate pour-over grind.
Front Street uses staged extraction: bloom with 30 g of water for 30 seconds, then pour in a small stream in circles until 125 g for the first stage. When the water level drops and is about to expose the coffee bed, continue pouring until 225 g and stop. When the water level drops and is about to expose the coffee bed, remove the dripper. The extraction time (starting from the beginning of blooming) is 2'00".
[Front Street Kenyan Thaithini Coffee Bean Flavor] Obvious smoked plum and cherry tomato, almond in the mid-palate, honey in the finish, juicy mouthfeel, and bright acidity. The Difference Between Front Street Kenyan AA and Kenyan PB In fact, it can be seen that these two Front Street beans have obvious differences in grade classification, and the roasting parameters and brewing parameters used by Front Street are also different. Under these conditions, differences in their flavor expression can also be perceived.
What the two have in common is that both have obvious smoked plum, cherry tomato, and honey flavors, and as the temperature drops they bring a slight nutty flavor, a juicy mouthfeel, and bright acidity. But AA's acidity is brighter than PB's, and its overall layering is higher; PB highlights the sweetness of berries and honey, and is overall clean and soft.
The above content is compiled by CoffeeHunters, a coffee news website.
