How to Describe Coffee Flavors? The Sensory Characteristics of Premium Guji Coffee

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Specialty coffee enthusiasts have likely heard about the Guokui coffee bean variety. So what exactly is Guokui coffee? From the Guokui coffee beans that entered competitions in 2017 to the Guokui 5.0 coffee beans in 2021, each year's Guokui has offered different coffee flavors. Over the past few years, Guokui coffee beans have also been quite controversial. Coffee beans, after all, are agricultural products, and their flavors change annually due to environmental variations. This is precisely why DW company has divided Guokui into multiple X.0 series.

Why are there so many varieties of Guokui coffee beans? Where does authentic Guokui coffee originate?

Let's return to 2017, when a natural processed coffee bean from DW company's Buku Aebl processing plant won the TOH natural process championship. At that time, a Chinese green coffee importer introduced this champion bean to China and named it "Guokui." This coffee bean then had intense strawberry and cream aromas. Additionally, Li Jianfei from Beijing used this Guokui coffee to win the runner-up position in the 2017 World Brewers Cup China region competition (other competing beans that year were Geisha). This also brought considerable fame to Guokui coffee beans. Note that during this time, Guokui coffee beans carried the title of 2017 TOH champion bean.

Subsequently, DW company expanded to 4 processing plants in the Hambela region: Buku Abel, Buku Saysay, Haro Soresa, and Tirtiro Goye. Then in 2018, they introduced Guokui 2.0, in 2019 launched Guokui 3.0 and 3.1, in 2020 released Guokui 4.0, and in 2024 they introduced Guokui 8.0.

Therefore, it's clear that the Guokui X.0 naming system is based on the year. When you see Guokui 3.0, you know it's coffee beans from the 2019 harvest season; when you see Guokui 4.0, you know it's from the 2020 harvest season. Naturally, Guokui 8.0 is from the 2024 harvest season. Strictly speaking, only natural processed coffee beans from the Buku Abel processing plant can be truly called Guokui coffee beans.

What are small bean Guokui coffee beans?

FrontStreet Coffee, in the 2018 and 2019 batches of Guokui coffee beans, discovered that the flavor was very close to the original Guokui, but the body and aftertaste couldn't match the original 2017 Guokui. Surprisingly, FrontStreet Coffee could still identify from these two batches of green beans some identical small green beans from the original Guokui batch. The 2017 Guokui coffee beans contained some particularly small bean varieties, which were the main source of Guokui's aroma. Therefore, Guokui containing these old Guokui small bean varieties is also called small bean Guokui. The coffee beans in Guokui 4.0 are generally smaller, which is why Guokui 4.0 performed better than the previous two years.

Guokui Coffee Bean Processing Method

Regardless of the year of Guokui coffee beans, the Buku/Bugu processing plant uses natural processing methods to handle the coffee beans. Due to the natural processing method, FrontStreet Coffee finds that in cupping new harvest season Guokui coffee beans each year, although there may be flavor differences, the characteristics of full berry fruit juice sensation, fermented flavors of ripe fruits, and moderately prominent sweetness are always present. This is one of the reasons why FrontStreet Coffee particularly likes Guokui coffee beans.

How does the new harvest season Guokui perform in flavor?

The first batch of Guokui coffee beans arrived in port this April. As loyal fans of Guokui coffee beans, FrontStreet Coffee immediately roasted them upon arrival and conducted cupping flavor comparisons with existing Guokui coffee beans.

Cupping is conducted within 8-24 hours after roasting the sample coffee beans. FrontStreet Coffee baristas typically use 200ml ceramic cups for cupping. The water temperature used for cupping is 94°C. The grind size is controlled to pass through a No. 20 standard sieve (0.85mm) at a rate of 70%-75%. The ratio is 11.1 grams of coffee grounds to 200ml of hot water, that is, 1:18.18, which extracts coffee concentration exactly within the 1.15%-1.35% Gold Cup range, with an immersion time of 4 minutes.

The flavor profile of small bean Guokui coffee is strawberry cream, citrus, passion fruit, and fermented wine aroma, while Guokui 5.0 coffee's flavor is berries, citrus, honey, mango, and floral notes. Indeed, small bean Guokui coffee's flavor is quite close to the 2017 champion Guokui, especially the strawberry cream flavor, which hasn't been tasted in the 2018-2021 Guokui X.0 series.

How to brew Guokui coffee beans?

To fully extract the rich layers of Guokui coffee beans, FrontStreet Coffee uses higher water temperature and finer grind size for extraction. However, to avoid over-extraction caused by high temperatures, they use faster flow rate drippers like the V60. The V60 dripper has a 60-degree conical shape. The conical angle allows coffee grounds to concentrate, and when pouring water, the flow automatically converges toward the center of the dripper, ensuring sufficient contact time between water and coffee grounds to extract appropriate coffee liquid. Additionally, the ribs on the inner side of the V60 dripper extend clockwise in a spiral from bottom to top, creating enough space between the filter paper and dripper, ensuring good water flow. Combined with the large hole at the bottom, the water flow rate is relatively faster than many other drippers.

Dripper: V60#01
Water temperature: 90-91°C
Coffee amount: 15g
Coffee-to-water ratio: 1:15
Grind size: Medium-fine (80% pass-through rate with China standard No. 20 sieve)

FrontStreet Coffee brewing method: Three-stage extraction. Bloom with 30g of water for 30 seconds. When pouring with a small water stream to 125g, segment. When the water level drops and is about to expose the coffee bed, continue pouring to 225g and stop. When the water level drops and is about to expose the coffee bed again, remove the dripper. The extraction time is about 2 minutes (starting from the beginning of blooming).

FrontStreet Coffee's Guokui: Floral notes, berries, citrus, sweet and sour plum, mango juice, honey, with a sweet aftertaste of black tea.

How to judge whether a cup of coffee is good?

Whether coffee tastes good largely depends on personal preference. For example, once when FrontStreet Coffee was sharing tasting coffee with customers in the store, some customers found the same coffee so sour it made their teeth chatter, while others found it full of sweetness and very delicious. From their perspectives, their judgments of taste are both correct, which shows the different taste thresholds between people.

Even if you don't like sour coffee, flavors like lemon acid, passion fruit acid, and grape acid are all positive flavors. The same goes for bitterness; some bitterness like dark chocolate is also a positive flavor. (Anyone who has eaten pure dark chocolate knows that kind of bitterness is extraordinary)

So what are negative flavors? Generally speaking, they are uncomfortable tastes, such as strong acidity, strong bitterness, sharp acidity, burnt bitterness, astringency, bitter aftertaste, and long bitter finish. Some non-taste negative sensations include hollowness, blandness, rough texture, and short aftertaste.

These negative flavor manifestations can stem from coffee bean quality, roasting quality, or brewing problems. By choosing a reliable coffee brand, you can basically avoid issues with coffee bean quality and roasting. The remaining factor is negative flavors caused by brewing problems.

Brewing problems can be roughly categorized into under-extraction and over-extraction. For example, under-extraction can lead to negative manifestations such as strong acidity, sharp acidity, astringency, light saltiness, thin texture, watery feel, and short aftertaste. Over-extraction can lead to burnt bitterness, astringency, long bitter aftertaste, rough texture, and so on. Therefore, as long as we can identify these flavors in coffee, we can infer what brewing problems caused these negative flavors, thereby using taste to judge the extraction status of coffee.

Under-extraction

Under-extraction generally occurs when sweet and bitter substances are not extracted, leading to prominent acidity and even sharp, stimulating sourness. If it's strong acidity, it might be caused by too little water. Sharp sourness, watery feel, and thin texture might be caused by coarse grind size combined with fast water pouring, resulting in short extraction time.

The occasional taste of light saltiness is also a manifestation of under-extraction. Normally, the chance of tasting saltiness in coffee is very low because it's masked by acidity and sweetness. In under-extracted coffee, the lack of sweetness masking allows the saltiness to be exposed, usually appearing in some under-extracted coffees with non-prominent acidity.

Under-extracted coffee often shows short aftertaste. Generally, aftertaste comes from the middle and later stages of coffee extraction. If this part is missing, it will result in short coffee aftertaste.

What situations easily cause under-extraction?

When we clearly perceive that coffee is under-extracted, we usually first think of problems like too coarse grind size, too low water temperature, too large coffee-to-water ratio, or too short contact time between coffee grounds and water, which lead to low flavor concentration. In fact, high concentration is also one of the manifestations of under-extraction. For example, some people are used to brewing more coffee grounds with less water, only extracting the flavors from the first half, while the flavors from the second half remain in the coffee grounds. Combined with high concentration, the taste is often both strong and sour.

When channeling occurs in the coffee grounds during pour-over brewing, meaning the water level is too high during pouring, breaking through the coffee grounds wall or overflowing the grounds wall, water flows away along the diversion ribs at the edge of the dripper. The coffee liquid that falls into the lower pot is certainly under-extracted. The blooming stage is to prepare coffee for flavor extraction. Therefore, uneven blooming can easily lead to different dissolution rates of coffee grounds in different areas. Unwetted particles need more time to fully release flavors.

Over-extraction, how to tell?

Over-extraction occurs because too many coffee substances are extracted, causing some unpleasant bitterness to also be extracted into the coffee. For example, bitterness and astringency caused by too fine grind or too long immersion time - this feeling is not just bitterness, but makes the entire mouth feel rough. This is because over-extracted coffee contains more polyphenolic substances, which bind with proteins in saliva, causing a rough sensation. Water temperature that's too high can easily cause coffee to have burnt bitterness. This bitterness is very stimulating and lingers in the mouth for a long time. From FrontStreet Coffee's experience, the appearance of such flavors is mostly due to too many fine particles or too fine water flow causing coffee to soak for too long or water temperature being too high. The solution is to adjust the grind coarser or lower the water temperature.

Of course, under normal circumstances, properly extracted coffee will show fruit-like acidity, such as the lively acidity of lemon and citrus, or fruit flavors with balanced sweet and sour like strawberries and plums. Then there's full sweetness, like honey and fructose. Moderate concentration shows clear flavors and rich layers. As well as persistent aftertaste, generally manifested as light floral notes and tea-like sensations.

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473