The Roasting Process in Pour-Over Coffee: Five Techniques and Four Parameters
Pour-over results come down to four elements: water temperature, grind coarseness, coffee-to-water ratio, and pouring technique. Temperature controls extraction strength, so light-to-medium roast beans are brewed around 91–93°C and medium-dark beans around 86–88°C. Adjusting one variable at a time is what lets home brewers move closer to a shop-style cup.
Five practical techniques are covered: the three-stage pour, the stirred bloom, the Japanese drip method, the single-pour method, and the volcano pour. Grind size and the roast level set during the roasting process both decide how fast water moves through the coffee particles. A dark-roast Golden Mandheling brewed at 86°C, for instance, gave a mouthfeel close to espresso.
With the rise of the third wave of coffee, pour-over coffee has attracted numerous enthusiasts with its ritualistic brewing process. However, many people feel that when brewing at home, the flavor never matches that of a coffee shop, yet they don't know how to adjust the blooming time, grind size, pouring method, or water temperature. This article by Front Street Coffee starts from the four major elements—water temperature, grind coarseness, coffee-to-water ratio, and pouring technique—to systematically explain how to brew a good pot of coffee, and breaks down in detail five practical techniques: the three-stage pour, the stirred bloom, the Japanese drip method, the single-pour method, and the volcano pour, helping you consistently reproduce your ideal flavor at home.
Since the rise of the third wave of coffee, pour-over coffee has continued to grow in popularity. The folks at Front Street generally feel that the process of holding the kettle and pouring water yourself throughout is itself a ritualistic experience. But many friends report that no matter how they brew at home, they can't reproduce the taste of a coffee shop, and they don't know whether to start adjusting the blooming time, grind size, pouring method, or water temperature. So how exactly should a good pot of coffee be brewed? Let Front Street Coffee walk you through it, one by one, from four dimensions: water temperature, grind coarseness, coffee-to-water ratio, and pouring technique.
Water Temperature
The higher the water temperature, the stronger the extraction power, and the coffee leans toward bitterness with a more intense mouthfeel; when the water temperature is lower, the extraction power weakens, and the coffee tends toward sourness with a mild, light mouthfeel. Pour-over temperature needs to be set according to the roast level of the coffee beans: light-to-medium roast beans are recommended at 91–93°C, medium-dark roast beans at 86–88°C. Front Street Coffee basically adjusts within this range. A customer once questioned this temperature, so Front Street Coffee brewed Golden Mandheling (dark roast) at 86°C, and the result was a mouthfeel almost comparable to espresso.
Generally speaking, darker-roasted beans suit lower water temperatures, while lighter-roasted beans suit higher water temperatures. A special reminder here: if you brew dark-roast beans with high-temperature water, or light-roast beans with low-temperature water, neither situation will produce ideal coffee flavor.
Pour-Over Coffee Bean Grind Size
Grind size refers to the size of the coffee particles, which directly affects the contact time between coffee and water. The finer the coffee grounds, the more substances water can extract in the same amount of time, but over-extraction is also easy to cause; the coarser the coffee grounds, the fewer substances extracted in the same amount of time, yet under-extraction is easy to cause. Front Street Coffee recommends using a Chinese standard No. 20 sieve with an 80% pass rate as a reference for pour-over grind size—this conclusion was reached after repeated testing and taste comparisons. Note that different coffee beans suit different grind sizes, so when the pour-over flavor is off, it's worth first checking whether the grind size is appropriate.
The finer the grind, the larger the surface area of the coffee and the faster the extraction speed. Front Street suggests: if you usually brew medium-roast beans and now want to brew light-roast beans, you can grind finer; similarly, if you usually brew light roast and are now brewing dark-roast beans, grind slightly coarser.
Coffee-to-Water Ratio
The coffee-to-water ratio refers to the ratio of coffee grounds to brewing water, determining the strength of the coffee, with common ratios being 1:10, 1:13, 1:15, and 1:16. Front Street Coffee recommends a 1:15 ratio, which is moderate in both strength and mouthfeel. Of course, everyone seeks a different coffee mouthfeel, so during extraction you can absolutely adjust the ratio according to the strength you want.
Pour-Over Coffee Techniques
1. Three-Stage Pour Technique
Pour-over coffee techniques are diverse, including the three-stage pour, single-pour, drip method, volcano pour, stirring method, and more. Front Street Coffee recommends beginners use the three-stage pouring method to brew; this technique suits light-roast, medium-light roast, and medium-roast coffee beans. The staged extraction of the three-stage pour can clearly present the front, middle, and back notes of the coffee, and is relatively good at ensuring the complete presentation of the coffee's flavor.
First Pour: Bloom (Helps Degassing)
During the roasting process that turns green coffee beans into roasted beans, a series of chemical reactions and physical changes occur; once a certain point is reached, a large amount of gas (mostly carbon dioxide) accumulates inside the beans.
Generally speaking, the fresher the coffee beans and the closer to the roast date, the more bubbles appear during blooming. Dark-roast beans also release more gas during blooming than light-roast beans. Front Street Coffee's beans are all freshly roasted, so customers are generally advised to rest the beans for three days first, letting the carbon dioxide release in advance, so that instability and under-extraction can be avoided during brewing.
After the gas is released during blooming, the coffee particles can absorb water evenly, and subsequent extraction will be more uniform. A good bloom not only allows the coffee grounds to degas quickly, fully, and evenly, but also lets the coffee grounds come into full and rapid contact with water, helping the coffee grounds be evenly extracted.
During blooming, pay attention to the following four points:
1. Before pouring water for the bloom, first level the coffee grounds.
2. Pour gently during the bloom.
3. During the bloom, as little extracted liquid as possible should drip down; when too much extracted liquid appears in the server, reduce the amount of water poured, or check the grind size. (If too much water is used for the bloom and a large amount of coffee liquid drips down, the falling water does not linger but directly carries out substances from the outer layer of the coffee grounds, and the off-flavors and astringency of the coffee's outer layer begin to dissolve out—coffee brewed this way is both weak and carries over-extracted off-flavors. If too little water is used for the bloom and no drops fall at all, it means the coffee grounds have not absorbed enough water, and some coffee has not degassed sufficiently, causing under-extraction.) Regarding this issue, Front Street Coffee, after many bloom tests, found that pouring water at twice the weight of the coffee grounds is relatively appropriate.
4. The bloom time is about 30 to 40 seconds. When the expansion of the coffee grounds' surface ends, you'll see the coffee surface shrivel—this indicates the bloom is complete and you can begin pouring. (If the bloom time is too long, the coffee easily develops bitterness and astringency; if too short, soaking is insufficient, and the coffee may be under-extracted or the flavor may not fully emerge.) Generally, the bloom's end time differs for each bean, but Front Street Coffee found this inconvenient for beginners—after all, beginners value standardization and ease of use. Therefore, on the premise that the coffee beans are still freshly roasted, Front Street Coffee recommends a bloom time of 30 seconds; experienced brewers can of course adjust the time themselves.
Second Pour
The second pour starts from the center, with a small stream poured into the bottom of the coffee bed. To concentrate the penetrating force of the stream, the circular movement range should be small—about the size of a one-yuan coin—and then spiral outward. From the start of the second pour, watch the water volume and try not to exceed the height of the coffee bed; that is, when the stream circles close to the filter paper, you can stop pouring.
Third Pour
As the originally thicker coffee bed along the filter paper becomes heavier from absorbing water, it slides down and thins as the water level drops; when the water level drops halfway, you can proceed with the third pour. From the start of the third pour, observe the extent of the water level drop, again pouring in circles starting from the center, with the water volume not exceeding the height of the coffee bed. At this point you'll also observe that the foam has covered the entire surface; the third pour should increase the tumbling of the coffee particles, making all the settled particles tumble and thereby dissolve out soluble substances.
The tumbling particles begin to settle once you stop pouring; at this point, the flow rate created by the dropping water level causes friction between the coffee particles. So once pouring stops, the coffee particles sink, causing clogging—pay special attention to the rhythm of pouring. If you break the pour too many times, it amounts to letting the coffee particles sit in water the whole time, which causes the final stage of extraction to produce astringency and off-flavors.
Causes of Extraction Failure and How to Improve
If you don't follow the key extraction points, failure comes easily. For example, coffee grounds that aren't fresh enough won't expand and can't bloom properly. If the coffee grounds are ground too coarsely, hot water will drop through quickly; if the particles are too fine, they will clog the dripper, brewing coffee with strong astringency. If the grind is uneven, the flavor components entering the hot water will also be uneven, making it hard to brew the taste you want.
When controlling the taste, also pay careful attention to the hot water temperature—you can't just eyeball it; you must measure precisely with a thermometer—that's the key to success. Keeping the filtration layer intact is especially important, otherwise hot water will drip down before the components are fully extracted, brewing weak, flavorless coffee. In the latter half of extraction, the proportion of unnecessary components increases, so proceed quickly to reduce the extraction of unnecessary components.
Take Front Street's Colombia Sidra coffee beans as an example: this is a single-origin coffee from Finca La Diviso in the Huila region, grown at an altitude of 1,700 meters, using double anaerobic natural processing. Ground into coffee powder, it has a very rich aroma of grapes, passion fruit, and citrus; brewed as black coffee, it has a rich and clear grape-juice character.
2. The Stirred Bloom Method Popular in Europe and America
Suitable for light-roast coffee beans
European-American stirring method: during the bloom stage, use a stirring stick to stir in a cross pattern. It is also a branch of the three-stage pour, developed as a pour-over technique only after 2012 World Brewers Cup champion Matt Perger. This approach can effectively enhance the release of aromatic substances in the coffee beans, amplify the coffee beans' flavor strengths, and enhance the coffee's mouthfeel so it isn't too thin.
The stirring method places high demands on coffee bean quality; using poorer coffee beans will amplify their undesirable flavors. In addition, the stirred bloom method is relatively suited to brewing light-roast coffee beans, and in grind size a finer grind is often adopted, which can increase the coffee grounds' water-contact area and raise the extraction rate. But if the degree of stirring isn't well controlled, over-extraction is also easy.
So we also recommend pairing it with pour-over gear known for fast extraction: the Hario V60 dripper uses alternating long and short spiral extraction ribs, increasing the flow rate; the Hario Buono kettle's cloud-like design, with its wide base, can provide a stronger penetrating force to the poured stream, keeping fine particles tumbling for a longer time. This is important because while the coffee grounds are tumbling, the release of internal substances is paused, thus avoiding the extraction of off-flavors caused by long soaking.
3. Japanese Drip Pour Method
Suitable for medium-roast or darker-roast coffee beans
The drip pour method is also called essence-style extraction: the drip method's stream is weak, disturbing the coffee bed as little as possible, reducing convection and increasing soaking time. Coffee made with this Japanese technique has high body, high sweetness, is rich and smooth, with a distinct texture.
Because the pour-over kettle's water needs to come out drop by drop, it's suitable to choose a flat-cut wide-mouth spout or a wide-mouth gooseneck kettle; the advantage of such kettles is that the thickness of the stream is highly controllable, making them more adaptable to the drip pour method. Paired with Kono's conical dripper—whose ribs stop less than halfway up the dripper's height, a design that lets the filter paper fully cling to the wall after absorbing water, greatly limiting the degassing space—this method is relatively suited to medium-roast or darker-roast coffee beans.
When starting to pour, we use drop-by-drop pouring, which increases soaking time; at a low coffee-to-water ratio, it lets the coffee grounds fully expand without producing any off-flavors. Then we pour with a fine stream and a coarse stream to extract the coffee's front-end floral and fruity aromas. The whole process takes about 4–5 minutes.
4. Single-Pour Technique
Its meaning is that after the bloom, only one uninterrupted pour is made, hence the name. After the bloom, one uninterrupted pour can keep the coffee grounds continuously soaking in water, and the retained liquid fully releases the aromatic substances within the coffee grounds; the flow rate increases continuously, and before the water volume overflows the dripper, reduce the stream. This technique mainly controls the water volume and flow rate—you need to know when to pour to achieve extraction of all stages without losing balance; an inappropriate pouring method will ruin the coffee's overall balance.
This approach mainly maintains a gentle flavor and a sense of balance. The downside is that, because the pouring technique is hard to control, water may pass through the upper position without coffee grounds and fall along the edge's filter paper, so the resulting coffee may be mixed with a watery taste.
5. Volcano Pour Technique
The "volcano pour" technique originates from Japan and suits dark-roast coffee beans, because these beans contain more carbon dioxide. Using the carbon dioxide in the beans, through multiple blooms, the coffee grounds puff up like a volcanic eruption. The "volcano pour" mostly uses a flannel filter cloth and a V60 dripper for brewing; because the center of the coffee bed is thicker, water is poured at a spot about the size of a one-yuan coin in the middle of the coffee grounds. The first half focuses on fully extracting without disturbing the coffee bed, while the second half pours evenly to prevent over-extraction of the central coffee grounds and to play a diluting role.
Advantages: The coffee has a rich, mellow mouthfeel and obvious sweet aftertaste.
Disadvantages: Over-extraction in the first half and under-extraction in the second half make the coffee liquid uneven; it must be fully shaken after brewing to blend into a perfect coffee. But shaking lowers the coffee's temperature—and if you extract at a high temperature to maintain warmth, the coffee becomes dry and astringent.
The above content is compiled by CoffeeHunters, a coffee news website.
