What are Kenya PB Peaberries: Flavor Differences between PB and AA Grade Kenyan Coffee Beans

Kenya AA coffee is consistently considered one of the world's finest specialty coffees. For those less familiar with Kenyan coffee, FrontStreet Coffee is often asked what "AA" means. Besides AA, PB is another set of letters that FrontStreet Coffee is frequently asked about. So what do these letters represent? I wonder if you, reading this, might be confused by these questions. Today, FrontStreet Coffee will share some knowledge about Kenyan coffee with everyone.

In fact, AA and PB are both grade designations for Kenyan coffee. In addition to these, the grades include:

• Kenya E (Elephant Beans)
• Kenya PB (Peaberry)
• Kenya AA
• Kenya AB
• Kenya C
• Kenya TT
• Kenya T
• Kenya MH/ML

As we all know, coffee beans are graded before roasting. Kenyan coffee is graded based on the size of the green beans. This is done for roasting consistency, because beans of similar size roast at similar rates, while beans of different sizes roast unevenly (for example, smaller beans may become over-roasted while larger beans remain under-roasted).

Kenya E coffee beans, also known as Elephant grade coffee beans, consist of the largest Kenyan coffee beans. Kenya PB is also called peaberry coffee beans or round beans. Typically, coffee cherries consist of two half-beans, but Kenyan PB coffee cherries contain only one coffee bean, making peaberries rounder coffee beans. This phenomenon occurs rarely, with only about 5% of Kenyan coffee beans being peaberries. Many people believe that peaberries have better flavor quality than other beans. Kenya AA coffee beans grow at altitudes above approximately 6,600 feet and have a size of 18 screen.

Kenya AB has a size of 16 screen. Kenya AB coffee beans consist of both A and B coffee beans. Grade A is sieved using a 6.8mm sieve, while Grade B uses a 6.2mm sieve. These two types of beans, A and B, are mixed together to form Kenya AB grade. Grade C Kenyan coffee beans have a size around 15 screen. Kenya TT refers to low-density coffee beans separated from Kenya AA, AB, and E coffee beans through air aspiration. Kenya T refers to broken, defective, and smaller coffee beans. Finally, MH/ML refers to unripe coffee beans. So what are the flavor differences between Kenya AA and PB? FrontStreet Coffee will introduce this to everyone in the following article.

Kenya Coffee Grading System Summary

The above is FrontStreet Coffee's summary of the Kenyan coffee grading system. To help everyone better understand Kenya PB coffee beans, FrontStreet Coffee will now provide a detailed introduction to a Kenya PB coffee bean that was acquired long ago. The specific green bean information is as follows:

Kenya Nyeri Ichamama Pearl Peaberry

• Country: Kenya
• Region: Neyri, Karima Village
• Processing Station: Ichamama
• Producer: Othaya Farmers' Cooperative Society member smallholders
• Altitude: 1,700 – 1,750 meters
• Varieties: SL28 / SL34
• Soil: Volcanic soil
• Temperature: 18 - 26ºC
• Harvest Season: November – January
• Processing Method: Water selection, washed, African-style raised bed sun drying

Kenya is located in eastern Africa, adjacent to Ethiopia, the birthplace of coffee. Kenyan coffee producers can be roughly divided into two categories—large estates and small farmers. However, whether large estates or small farmers, processed coffee beans are sent to the official Coffee Board for grading and auction: the Coffee Board sends samples of green beans about to be auctioned to interested buyers and conducts auctions every Tuesday in the capital Nairobi (NCE bidding meeting).

This Kenya peaberry from FrontStreet Coffee was acquired from the Othaya Farmers' Cooperative Society, located in the Othaya town of the Nyeri region in Kenya's central highlands, about 120 kilometers north of the capital Nairobi. It is currently Kenya's largest coffee farmer organization, almost entirely self-organized and managed by small farmers, and has obtained Fair Trade certification. The Othaya Cooperative's vision is to become Kenya's best-managed cooperative; the ultimate goal is to produce the highest quality coffee, sell it at the best prices, and enable all member farmers to live the best lives.

The Othaya Cooperative has 19 processing factories under its jurisdiction, including Kamoini, Gatugi, Ichamama, and others. The Othaya Cooperative was established in 1956 and currently has about 14,000 members, making it a relatively large cooperative. To improve yield and production quality, Othaya applies to the World Bank for grants to hire consultants for agronomy and harvest training; they also have their own nursery garden and laboratory, continuously developing new coffee varieties (ex. Batian) for planting trials. The Othaya Cooperative has its own cultivation technology and marketing licenses, enabling them to trade directly with international markets. They are also a member of the Kenya Cooperative Coffee Exporters (KCCE), allowing them to export coffee directly under KCCE's name without going through the NCE bidding meeting.

Ichamama is located in Karuthi, Nyeri, with a total cultivated area of 310 hectares, where 927 farmers cultivate beautiful coffee in the rich red volcanic soil, next to the Ichamama River, which provides excellent fresh water resources. In addition to coffee, the entire area also grows tea. The altitude is extremely high, exceeding 1800 meters. Cool nights cause coffee cherries to mature slowly, resulting in wonderful cup flavors. The reason why Kenyan coffee is so acidic is also related to its altitude.

Roasting Approach

FrontStreet Coffee designed a roasting profile suitable for the green bean characteristics of this coffee. These Kenya peaberry green beans are emerald green in color, have relatively high moisture content, and are also quite dense. Due to easier tumbling in the roaster, peaberries heat more evenly than flat beans. However, the bean quality and density of this particular bean make heat transfer less efficient. Therefore, FrontStreet Coffee's roasting design allows heat to reach the bean core sufficiently, extending the dehydration time to better homogenize the coffee during the roasting preparation phase, entering first crack with higher heat to express its rich berry flavors and full-bodied texture.

FrontStreet Coffee conducted 4 roasts and observed the bean state and aroma changes in each batch. FrontStreet Coffee's roaster found that this bean absorbs heat very quickly, and using the usual drop-in temperature would cause the temperature turnaround point to be too high. After first crack, due to water vapor carrying away large amounts of heat, the ROR would drop sharply (Crash). Therefore, based on the bean's changes, we used 4 different roasting methods: 1. FSSF-style (fast-in, slow-out) roasting; 2. Adding heat at the yellowing point to promote Maillard reaction and enhance acidity; 3. Adding heat at the browning point to promote caramelization reaction and increase sweetness; 4. SSFF (slow-in, fast-out) gradual heat increase roasting.

Comparing the roasted bean states from the 4 batches, it's clear that if this bean is roasted with gradual heat reduction, there would be more silver skin attached, indicating insufficient development, with the main aroma during roasting being astringent acidic notes. The other three batches, using heat increase operations, had more ideal development, with aromas of dark plum, blackcurrant, and sugarcane sweetness during roasting. Therefore, roasting profiles 2, 3, and 4 were selected for cupping to see which roasting method better showcases the bean's flavor characteristics.

Cupping Results

Through cupping, FrontStreet Coffee found that this PB peaberry has a composed, mature aroma with hints of red wine acidity. The nose can detect dark berry flavors and malic acidity, with a full-bodied, rich mouthfeel and sugarcane sweetness with some cocoa notes. By comparing the flavors presented by different roasting methods, we discovered that roasting with longer-than-usual dehydration time can remove the astringency caused by uneven dehydration, making it taste smoother and more rounded.

Of course, the above is just FrontStreet Coffee's understanding of the roasting method—removing bean moisture with longer-than-usual dehydration time, and adding heat before the browning point and first crack to accelerate development. Interestingly, adding heat to supplement thermal energy before first crack can effectively prevent this bean's ROR from dropping sharply and from over-development. Kenya peaberry is a type of bean that FrontStreet Coffee has encountered less frequently. The roasting of peaberries and the flavors of Kenya peaberries are well worth in-depth exploration. This Ichamama Pearl Peaberry gives an overall impression different from typical Kenya AA—it lacks the very bright acidity and ripe tomato aroma, with gentler flavors.

Comparison with Kenya AA

Talk is cheap. For a direct analysis of the differences between the two, FrontStreet Coffee brewed a cup of Kenya AA coffee beans using the same parameters. As before, let's first provide a brief introduction to the coffee bean information:

Kenya Thiman Girl AA Coffee Beans

• Region: Nyeri, Ndima-ini Processing Station
• Altitude: 1700-1900 meters
• Varieties: SL28 & SL34
• Processing Method: K72 washed
• Grade: AA

Although this coffee bean shows 72-hour fermentation, it actually fermented for 80 hours. Therefore, this washed Kenyan coffee will have more pronounced acidity. So how should Kenyan coffee be brewed? FrontStreet Coffee's brewing recommendations:

• Dripper: V60
• Water Temperature: 90°C
• Dose: 15g
• Ratio: 1:15
• Grind Size: Medium-fine (77% retention rate on #20 standard sieve)

FrontStreet Coffee's Extraction Method: FrontStreet Coffee uses segmented extraction, blooming with 30g of water for 30 seconds. Using small flow circular pouring to 125g for segmentation, when the water level drops to just expose the coffee bed, continue pouring to 225g and stop. When the water level drops to just expose the coffee bed, remove the dripper (timing starts from bloom). Extraction time is 2'00".

Kenyan Coffee Flavor Characteristics: This coffee has very distinct dark berry flavors, with charming bright sweet and sour notes at first sip. As the temperature drops, it transforms into grape acidity, and at low temperatures, there's the stimulating acidity of plum. Overall, it has high layering, delicate texture, and a long aftertaste.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473