Yirgacheffe Coffee Beans Pour-Over Flavor Characteristics - G1 and G2 Differences and Grading System

An Introduction to Yirgacheffe Coffee

The first specialty coffee I ever encountered was Yirgacheffe, with its elegant floral aromas, bright acidity, and clean taste that remains unforgettable to this day. I believe many people's first specialty coffee bean was also Yirgacheffe. Here, FrontStreet Coffee would like to introduce Yirgacheffe to everyone.

Yirgacheffe Growing Region

Yirgacheffe is located on the eastern edge of the East African Rift Valley, at an altitude of 1,800-2,000 meters, making it one of the highest altitude coffee growing regions in Ethiopia. To the west lies Lake Abaya, which has been a wetland since ancient times with abundant water resources, providing excellent resources for Yirgacheffe's washing stations.

Yirgacheffe was originally a small town in Ethiopia, located in the West Arsi administrative region. This town has been a wetland since ancient times—the ancient word "Yirga" means "to settle down," and "Cheffe" means "wetland."

Yirgacheffe is one of the highest altitude coffee growing regions in the world and synonymous with Ethiopian specialty coffee. With altitudes ranging from 1,700-2,100 meters, it enjoys cool, foggy weather year-round, spring-like seasons, and terrain conditions and unique cultivation systems that provide optimal conditions for growing specialty coffee beans. Yirgacheffe is part of the West Arsi region but was separated due to its unique flavor profile, establishing its own style and becoming the most renowned growing region in Africa.

Yirgacheffe Coffee Bean Varieties

Yirgacheffe coffee varieties are local indigenous landraces, small-seeded varieties with relatively round shapes and very small beans, mostly between 14-15 screen size. Ethiopia is known as the natural gene bank of coffee, with numerous varieties that are difficult to identify and classify. Additionally, the Ethiopian government,出于对天然咖啡的保护, is unwilling to disclose information about these varieties, so exported Ethiopian coffee beans are often collectively referred to as "Heirloom" varieties.

Local Processing Methods

Washed Processing Method

The washed method can remove impurities (stones or garbage) and defective beans through each step, resulting in uniform appearance of green beans with excellent market quality. It is generally considered to have high quality, thus trading prices are higher than coffee beans processed by natural drying methods. However, the more detailed the work division, the more procedures and hygiene management aspects involved, and the higher the risks. Therefore, washed processing does not necessarily equal high quality. FrontStreet Coffee believes that washed processed coffee has more pronounced acidity, better cleanliness, medium mouthfeel, and the most consistent green bean quality.

Washed processed coffee is formed through the following steps:

1. Removing Floaters
Coffee beans are poured into large water tanks. Underdeveloped, low-quality beans will float to the surface, while mature, full fruits will sink to the bottom. At this point, the floating beans on the surface are scooped out, completing the floater removal step.

2. Removing Pulp and Fruit Flesh
Using a pulping machine, the outer skin and fruit flesh of the coffee cherries are removed. (This leaves mucilage, parchment, and silver skin).

3. Fermentation
The purpose of this step is to use biological processing methods to remove the mucilage. The coffee cherries processed by the pulping machine are placed in...

4. Washing
After completing fermentation and removing mucilage, since fermentation bacteria and impurities will remain on the coffee beans, the beans are washed again. To ensure thorough cleaning, this step consumes large amounts of fresh water.

5. Drying and Removing Parchment, Silver Skin
Usually, machines (or sun-drying) are used to dry the coffee cherries until moisture content drops to 10-14%. Then, hulling machines are used to remove the remaining parchment and silver skin, completing the processing.

Pros and Cons of Washed Coffee Bean Processing

Advantages:

1. All processing steps of the washed method are done indoors, which can minimize impurities in the coffee beans and achieve the highest quality.

2. Since the pulp is removed at the beginning, there's no need to worry about mold issues like in the natural drying method.

3. The appearance is more complete with excellent market quality.

Disadvantages:

1. The process is complex and tedious, making costs much higher than the natural drying method.

2. It requires large amounts of fresh water. To obtain 1 kilogram of coffee beans, 40-50 liters of fresh water are needed, so it's less used in water-scarce regions.

Flavor: Due to fermentation, coffee beans usually have bright acidity and fruit aromas.

During fermentation, biological processing methods are used to remove mucilage. After completing fermentation, continuous flowing fresh water is needed to thoroughly clean fermentation bacteria and impurities remaining on the coffee beans, which requires large amounts of fresh water. Therefore, it's less used in water-scarce regions. Although the washed processing method doesn't require worrying about mold issues, the fermentation process does have a certain impact on coffee flavor, so specialty coffee enthusiasts generally don't adopt this processing method. Washed coffee has a clean taste without off-flavors, and coffee beans usually have bright acidity and fruit aromas.

Natural/Dry Processing Method

The natural processing method, also known as the "natural drying method," is one of the oldest and most traditional processing methods. Coffee cherries are dried immediately in the sun after harvesting. It's more common in regions with abundant sunlight or water scarcity. For example, nearly 70% of coffee cherries from all growing regions in Ethiopia are processed using the natural method. FrontStreet Coffee believes that compared to washed processed coffee, natural processed coffee has lower acidity, higher sweetness, clearer mouthfeel, but slightly less cleanliness. In terms of flavor, it produces more berry-like notes and is more complex.

Natural processed coffee is formed through the following steps:

1. Collection & Sorting
After harvesting, coffee cherries are first manually sorted to remove defective coffee cherries, including overripe, unripe, insect-damaged ones, as well as foreign objects other than the fruit.

2. Drying
The sorted coffee cherries are sent to drying areas for drying. Different regions may use different drying racks—some use tarps, some use raised beds, some use concrete floors, etc. The drying time averages 3 to 4 weeks until the coffee moisture content drops to 11% to complete the drying process.

3. Hulling
After drying, the coffee cherries are sent to processing plants for hulling and even polishing. The skin and fruit flesh are removed during this step.

4. Sorting, Grading & Storage
The hulled green coffee beans are sorted again to remove coffee beans with poor appearance. This reflects the quality of the drying process—over-dried coffee beans are more fragile and may break into fragments during hulling; while under-dried coffee beans have too much moisture, making them prone to bacterial growth and mold. After sorting, they are sent to warehouses for storage until export.

Pros and Cons of Natural Coffee Bean Processing

Advantages:

Except for the first step which requires water to filter out low-quality beans, other steps don't need any water and can be reused repeatedly. In regions with limited water resources, this method is simply fantastic!

Also, because natural processed beans have irreplaceable special flavors, some excellent farms have started taking natural processing seriously, such as drying them on raised beds to prevent contamination and careful selection. Thus, today we can see many high-quality natural processed coffee beans.

Disadvantages:

The natural method is completely dependent on weather, making it difficult to control the drying degree of coffee cherries. If the drying field isn't clean, it's easy to mix in impurities. During the natural drying process, the fruit flesh of coffee cherries isn't removed, so mold and rot often occur. Therefore, in many people's view, naturally processed coffee beans have poor quality control and won't achieve high grades.

Flavor: Natural processed coffee beans have uneven appearance with large color differences. However, because the coffee beans mature naturally inside the fruit without interference from external environments, natural processed coffee beans have more intense flavors, with wine-like fermentation notes and sweetness.

Yirgacheffe coffee natural processing involves selecting usable coffee cherries, then placing the entire fruit flesh and skin intact on raised beds for natural drying. It is this labor-intensive raised bed drying method that isolates contact with the ground, preventing earthy off-flavors during the drying process and creating exceptionally clean fruit flavors. After more than two weeks of natural drying, the dark brown coffee cherries are professionally stored and await full flavor development. Only before shipment are the coffee beans removed from the coffee cherries—one can imagine the sweetness.

Yirgacheffe Coffee Bean Grading System

Before ECX (Ethiopian Commodity Exchange, established in 2012) appeared, CLU (Cupping and Liquoring Unit, a department under the Ethiopian Ministry of Agriculture) classified washed processed coffee bean export grades as G1 and G2, while natural processed ones were G3, G4, G5—meaning the highest grade for natural beans was Grade 3 - G3.

After ECX emerged, its grading system for Ethiopian coffee beans is divided into two aspects.

On one hand, it defines grading based on defect rates in coffee beans. Whether washed or natural processed, for export green beans, if there are fewer than 3 defective beans per 300g, the grade is G1; if there are 4-12 defective beans per 300g, the grade is G2.

After ECX was established in 2008, it uses a combination of physical attribute characteristics of green coffee beans and cupping flavor characteristics for grading.

ECX classifies all coffee into three types based on processing methods (non-washed and washed):

a. Specialty: Few defects, high cupping quality

b. Commercial: Doesn't reach specialty grade but is higher than local/domestic consumption grade

c. Local/Domestic: Many defects (unripe beans), off-season, and poorly stored coffee with relatively poor flavors. (Consumed internally in Ethiopia, not circulated in international markets)

Among these, Specialty and Commercial are for export to international markets. Different types have slightly different grading standards.

Differences Between Yirgacheffe G1 and G2

Appearance Comparison

In terms of green bean appearance, G1 and G2 sizes and shapes are very similar, but G2 makes it easier to find insect-damaged and other defective beans.

Flavor Comparison

Then we conducted cupping comparisons. Through cupping these two washed processed Yirgacheffe G1 and G2, we reached the following results:

G1 and G2 both show citrus, fruit tea, honey, and berry flavors. The difference is that G1 has higher cleanliness and clearer recognition, while G2's taste seems somewhat lighter and slightly muddled. In terms of sweetness, G1 has a slight advantage.

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