How Does Coffee Extraction Work in a Pour-Over?

Pour-over beginners can focus on seven elements: fresh beans, grind size, water temperature, water quality, dripper choice, coffee-to-water ratio and brewing time. Coffee extraction itself happens in three stages during the pour: wetting, when water first soaks the grounds; dissolution, when soluble flavor compounds leave the coffee; and diffusion, when remaining solids move into the water.

Grind size is the lever that most affects the result. Fine grounds pack the filter paper, slow the flow and lengthen extraction time, which can pull out woody or off notes. Coarse grounds leave bigger gaps, so water contacts less coffee, resistance drops and the brew runs fast. A washed Ethiopian Sidamo Natural Huakui 8.0 serves as the worked example for the full standard process.

For those new to pour-over coffee, the array of equipment and brewing techniques can often feel overwhelming. Drawing on years of pour-over experience, Front Street Coffee has compiled seven simple and easy-to-understand core points for beginners, covering coffee bean freshness, grind size, water temperature control, water quality selection, dripper choice, coffee-to-water ratio, and brewing time, helping novices grasp the essentials without having to sift through piles of information. The latter part of the article also delves into the three stages of coffee extraction—wetting, dissolution, and diffusion—and uses an Ethiopian Sidamo Natural Huakui 8.0 as an example to walk through a complete standard pour-over process, tightly integrating theory with practice.

The specialty coffee industry has flourished in recent years, and pour-over coffee has gradually entered the public eye. However, for those just starting out, the wide variety of brewing equipment and pouring techniques often leave them at a loss. Many friends come to Front Street asking how to get started with pour-over coffee. In this article, Front Street will discuss the seven key elements of pour-over coffee, as well as the basic principles behind pour-over extraction.

Based on long-accumulated pour-over experience, the baristas at Front Street Coffee have distilled this concise seven-element checklist, aiming to let learners clearly know what aspects to focus on when brewing coffee without having to consult extensive literature. 1. Use freshly roasted coffee beans Front Street has always held that the ideal flavor window for coffee beans is thirty days. Once this period passes, aromatic molecules gradually diminish as carbon dioxide escapes, and the brewed coffee may taste flat and uninteresting. For this reason, every time Front Street explains brewing knowledge, it repeatedly emphasizes "always use freshly roasted coffee beans."

2. Coffee bean grind size The finer the grind, the more easily coffee grounds accumulate at the bottom of the filter paper, increasing resistance to water flow, which slows the flow rate and prolongs extraction time. Coffee brewed this way often carries unpleasant flavors like woody or off notes. Conversely, the coarser the grind, the larger the gaps between grounds, the less coffee the hot water can contact, the lower the resistance, the faster the coffee drips, and the lower the extraction yield—naturally resulting in a thinner flavor.

To find the most suitable grind for each bean, Front Street recommends purchasing a No. 20 cupping calibration sieve with an aperture of 0.85 mm. Take 10 grams of coffee beans, first adjust to an approximate grind setting and grind into powder, pour into the sieve and sift, then weigh the fine particles that pass through (sift until no more powder can pass). When the pass-through rate reaches 80% (i.e., 8 grams sifted from 10 grams), that corresponds to the most suitable grind for medium-light roasted beans; a pass-through rate between 70% and 75% (7 to 7.5 grams from 10 grams) suits medium-dark roasted beans. If the pass-through rate exceeds the appropriate range, adjust the grind coarser; if it falls short, adjust finer. 3. Controlling brewing water temperature Front Street Coffee uses different water temperatures for beans of different roast levels. During roasting, substances inside the coffee bean gradually diminish as the roast deepens, so dark-roasted beans require lower water temperatures to avoid extracting excessive off-flavors. For medium-light roasted beans, Front Street Coffee recommends water at 90–91°C; for medium-dark roasted beans, 87–89°C is advised.

4. The influence of water quality The mineral composition in water—such as calcium, magnesium, sodium, and potassium ions—can alter coffee's thermodynamic extraction capacity, thereby affecting the final flavor. Front Street Coffee does not recommend directly heating tap water for coffee, as tap water contains many impurities that can easily extract unpleasant flavors.

5. Choosing a dripper Front Street recommends beginners start with the V60 01 dripper. The V60 cone-shaped dripper has a wider opening, and with its distinctive spiral curve rib design, air escapes more smoothly, thereby improving extraction quality. Although the mouthfeel may not be heavy, the bright acidity and vivid aroma brought by high concentration are its highlights.

6. Coffee-to-water ratio for pour-over Below is the correspondence between coffee-to-water ratio and taste based on SCA Golden Cup extraction theory:

【Bold taste】1:10–1:11 (i.e., 1:12.5–1:13.5 per the Golden Cup standard) 【Moderate taste】1:12–1:13 (i.e., 1:14.5–1:15.5 per the Golden Cup standard)

【Light and refreshing】1:14–1:16 (i.e., 1:16.5–1:18.5 per the Golden Cup standard)

When the ratio of coffee bean weight to brewing water falls between 1:14.5 and 1:15.5, it most easily lands in the golden range of 18%–22% extraction yield and 1.15%–1.35% concentration, which is why Front Street Coffee consistently recommends brewing at 1:15.

7. Brewing duration for pour-over

During extraction, the aromas and flavors from the early stage are the most intense, with higher concentration; the later it goes, the lighter the flavor and aroma become. At the same time, the amount of water poured also affects extraction time. Front Street Coffee typically uses 15 grams of coffee, and depending on the bean, at a 1:15 coffee-to-water ratio, controls brewing time within 2 to 2 minutes 30 seconds, which makes it less likely to cause over-extraction or under-extraction.

Having covered the seven elements, let's now discuss the extraction principles of pour-over coffee.

Brewing coffee is essentially the process of extracting molecules from coffee cells. This process consists of three steps: wetting, dissolution, and release. The three occur in sequence and influence one another, ultimately creating the coffee's flavor.

【Wetting】

Literally, it means the coffee grounds are moistened upon contact with water—this is the starting point for coffee cells to begin releasing molecules, which is what Front Street often calls the blooming stage.

【Dissolution】

Dissolution refers to the process by which soluble molecules in coffee cells dissolve into hot water. This is the most critical step, determining the final extracted coffee flavor—what Front Street often calls the extraction stage.

A coffee bean is 70% composed of insoluble cellulose, with the remaining 30% being soluble aroma molecules. Upon contact with water, these molecules dissolve out in order of size. The smallest molecules come out first, including acids and aromas such as floral notes and citrus acidity; next are medium-sized sweet compounds, like fruity sweetness, honey, and brown sugar sweetness; finally come large-molecule bitter notes. This is why coffee has such layered and rich flavors. So if you prefer a sweeter, more fragrant taste, shorten the extraction time, because the longer hot water stays on the coffee grounds, the more bitter molecules are dissolved.

【Diffusion】

After aroma molecules dissolve, they leave the coffee cells through osmosis—this process is called diffusion. Aroma molecules diffuse into the hot water, forming the final coffee extract. As Front Street mentioned earlier, a cup of coffee extracts in the order of acidity first, then sweetness, and finally bitterness, so after brewing, be sure to swirl the coffee a few times to let the liquid blend evenly—only then can you taste the fullest flavor.

Now that the principles are covered, Front Street Coffee will actually brew a batch of Ethiopian Front Street Sidamo Natural Huakui 8.0 to see how the baristas do it.

Front Street Ethiopian Sidamo Natural Huakui Coffee Beans Region: Guji Hambela Processing Station: Buku Able Altitude: 2,350 meters Variety: Local heirloom varieties Processing Method: Natural process

Front Street Coffee pour-over parameters: Hario V60, coffee-to-water ratio 1:15, grind size BG#6S (80% pass-through on Chinese standard No. 20 sieve), water temperature 90°C.

In terms of pouring technique, Front Street Coffee uses twice the coffee weight in water for blooming, i.e., 30 grams of water, with a blooming time of 30 seconds. Then, pour in a slow circular stream until reaching 125 grams for a pause, and when the water level drops to nearly exposing the coffee bed, continue pouring until 225 grams and stop; when the water level again drops to nearly exposing the coffee bed, remove the dripper. Total extraction time (timed from the start of blooming) is 2 minutes 00 seconds.

【Front Street Ethiopian Sidamo Natural Huakui】Brewed flavor: At high temperatures, it carries almond aromas; as it cools, citrus acidity emerges, with a full berry juice mouthfeel, accompanied by a lemon black tea-like tea sensation, and a lasting sweetness.

The above content is compiled by CoffeeHunters, a coffee news website.