Introduction:Grind size is one of the key factors influencing the flavor of pour over coffee. This article uses an Ethiopian Yirgacheffe Candlelight (naturally processed, light roast) as a sample, and through a comparative test of three different grind sizes, analyzes its impact on extraction efficiency and flavor expression. From too fine to slightly coarse grind settings, we explore how adjusting the grind size can bring out the best flavor layers, helping coffee enthusiasts find parameters that suit their taste.
In the world of pour over coffee, grind size is not just a technical parameter but also a key variable affecting the final flavor of the coffee. Especially for light-roasted specialty coffee beans, different grind coarseness will directly affect aroma release, acidity-sweetness balance, and overall mouthfeel. Through practical testing, this article takes Ethiopian Yirgacheffe Candlelight coffee beans as an example, observing the extraction performance under three different grind sizes, and deeply analyzing their influence on flavor presentation.
The Yirgacheffe Candlelight selected for this test is naturally processed, light roasted, and grown at an altitude of about 1750–2000 meters, with the variety being a local landrace. This bean typically exhibits bright tropical fruit notes, including citrus, mango, and nectarine. If extracted properly, you can also perceive a soft creaminess and a sweet aftertaste. However, if the grind size is not well controlled, these delicate flavors can easily be masked or become unbalanced.
The experiment used three sets of grind settings with different fineness levels, corresponding to the 20-mesh sieve passing rates in the Chinese standard: BG-5I (75%, slightly medium-fine), BG-5T (58%, medium-fine), and BG-7D (43%, slightly coarse). Each test used 15 grams of coffee grounds, a brew ratio of 1:15, water temperature maintained at 90°C, and a consistent pulse pouring technique, keeping other variables as identical as possible while only changing the grind size.
First is the finest BG-5I setting (20-mesh sieve passing rate 75%). This group used 35 grams of water for a 30-second bloom, followed by pouring up to 132 grams for the first pour, then continued pouring to 226 grams when the water level was about to expose the coffee bed, ending the brew. Total extraction time was approximately 2 minutes and 7 seconds. In terms of flavor, this group exhibited noticeable fermentation aromas along with citrus, mango, and nectarine tropical fruit notes, but the overall mouthfeel was bitter, with heavier off-flavors and a pronounced lingering bitterness. This indicates that too fine a grind can lead to over-extraction, releasing excessive bitter compounds from the coffee, thereby masking the intended bright fruity notes and layered complexity.
Next is the moderately fine BG-5T setting (20-mesh sieve passing rate 58%). The bloom also used 32 grams of water, followed by pouring to 125 grams after 30 seconds for the first pour, then topped up to 227 grams before removing the filter. Total extraction time was 1 minute and 56 seconds. This group delivered the most balanced result—not only clearly showcasing the citrus, mango, and nectarine fruit aromas, but also bringing out a creamy body, with even a subtle nutty note detected in the later stages. The overall mouthfeel was rich and full, with pronounced sweetness and a long finish. It was regarded by the author as the most suitable daily grind size to bring out the potential of this coffee. This setting also showed good uniformity and was better at avoiding localized over-extraction or under-extraction issues.
Finally, there’s the slightly coarse BG-7D setting (20-mesh sieve passing rate 43%). Using 34 grams of water for a 30-second bloom, pouring was done up to 132 grams for the first pour, then continued to 225 grams to finish. Total extraction time was about 1 minute and 53 seconds. The flavor of this group was relatively thin—while tropical fruit, honey, and creamy notes were still perceptible, the overall layering was weaker, lacking the richness and body expected from a naturally processed bean. The finish was also rather dull. This reflects how a coarse grind allows water to flow through too quickly, preventing certain flavor compounds from fully dissolving and resulting in under-extraction.
Comparing all three results, it’s clear that too fine a grind (like BG-5I) makes the coffee overly intense and dominated by bitterness, thereby masking the bright tropical fruit character of the Yirgacheffe Candlelight. The medium-fine BG-5T fully showcases the fruitiness and creamy texture, delivering the most balanced and layered profile. Meanwhile, the slightly coarse BG-7D, due to under-extraction, appears thin in flavor and struggles to present the bean’s full characteristics.
Apart from grind size, several other key elements are essential for consistently brewing a great cup of pour over coffee. First is the initial extraction phase, which is usually where aroma and acidity are most pronounced. The substances dissolved during this stage have a significant impact on the overall flavor, so it’s recommended to maintain a stable and even water flow to avoid channeling caused by concentrated pouring. The later extraction phase tends to release more woody and fibrous compounds, which—if not managed well—can introduce excessive bitterness or astringency. Adjusting water flow speed and angle accordingly is advised.
Another crucial factor is water temperature. For light to medium-roasted coffee beans, such as the Yirgacheffe Candlelight in this test, a water temperature of 90–92°C is ideal. If the temperature is too high, bitter compounds may be excessively dissolved, even resulting in burnt notes. Conversely, if the water is too cool, it may cause the acidity to become overly sharp, with insufficient sweetness and body. For medium-dark or dark-roasted beans, the temperature can be slightly lowered to 88–85°C to avoid over-extraction-induced bitterness and harshness.
This test clearly demonstrates that grind size has a decisive impact on the flavor direction of pour over coffee. It is recommended that coffee enthusiasts, in their daily brewing, adjust grind coarseness according to bean type, roast level, and personal taste preferences. Coupled with stable water temperature and flow control, gradually find your own optimal extraction parameter combination.
The above content is compiled by CoffeeHunters, a coffee news website.
