Coffee Basics: Pour-Over Brewing Time & Typical Extraction Duration

FrontStreet Coffee has noticed that many beginners who are new to pour-over coffee pay great attention to brewing parameters such as coffee dosage, water-to-coffee ratio, water temperature, pouring technique, and grind size, yet treat extraction time with a casual "good enough" attitude... This approach simply won't work! Extraction time is incredibly important!!!

Why is Extraction Time So Important?

Only 30% of a coffee bean consists of soluble flavor compounds, while the remaining 70% is woody fiber. This means coffee flavors aren't infinitely extractable. Of this 30% of soluble flavor compounds, we only need to extract 18%-22% to achieve optimal flavor.

During the extraction process, the early stage maximally dissolves small molecular flavor compounds (acidity and sweetness) from the coffee particles, which determines the coffee's taste and aroma. The later stage begins to dissolve large molecular flavor compounds (bitterness) from the coffee particles. When these heavier flavor compounds are appropriately released, they can enhance the coffee's body and richness; however, excessive release will bring bitterness and astringency to the coffee.

This means that with other parameters remaining constant, the longer the coffee extraction time, the higher the coffee concentration, with more large molecular flavor compounds from the tail end, resulting in coffee that overall appears intense and charred-bitter; too short an extraction time results in lower coffee concentration, with only small molecular flavor compounds being extracted, making the coffee overall appear acidic, sweet, and thin.

In pour-over coffee, every factor is interconnected, so there's no fixed standard for extraction time, but there is an optimal range. Based on FrontStreet Coffee's brewing experience, to achieve a cup of pour-over coffee with perfectly balanced flavors (under normal circumstances), the optimal total extraction time for 15g of coffee grounds is between 1 minute 50 seconds and 2 minutes 20 seconds.

Should Pour-Over Timing Start Before or After the Bloom?

The optimal total extraction time mentioned by FrontStreet Coffee begins the moment water contacts the coffee grounds. Taking freshly roasted and properly rested beans as an example, after grinding to the appropriate coarseness, inject twice the amount of water as the coffee dosage (for 15g of grounds, inject 30g of water). The optimal bloom time is 30 seconds starting from when water injection begins.

During these 30 seconds, the coffee particles will release large amounts of carbon dioxide as well as acidic and sweet flavor compounds. If we only start timing for 30 seconds after completing the water injection, we're actually extending the bloom time, because injecting 30g of water typically takes 8-10 seconds. If you're brewing light roast coffee beans, this 10-second difference will likely cause the coffee to develop astringency!

What Factors Affect Extraction Time?

/ The Impact of Coffee Drippers

The angle, ribs, and shape design of different coffee drippers all affect the speed at which water passes through the coffee bed, resulting in faster or slower extraction times. For example, the V60 dripper, with its spiral long-rib design and large bottom aperture, allows water to pass through the coffee bed relatively quickly, resulting in somewhat reduced extraction time.

Another example is the Kono dripper, whose short rib design extends only to 1/3 of the dripper. The ribless section can create a seal with the filter paper, slowing down the speed at which water passes through the coffee bed, resulting in extended extraction time.

/ Coffee Grind Size

When coffee beans are ground finer, the gaps between coffee particles become tighter, water flow slows down, and extraction time extends. Excessively long extraction will cause flavor compounds to be over-extracted, leading to intense coffee.

When coffee beans are ground coarser, the gaps between coffee particles become larger, water flow speeds up, and extraction time shortens. Too short an extraction won't allow enough time for flavor compounds to dissolve, resulting in bland coffee.

/ Thickness of the Coffee Bed

Using the V60 dripper as an example, the 01 size dripper is suitable for brewing 15-20g of coffee grounds, while the 02 size dripper is suitable for 20g-30g of coffee grounds. (With the same beans and grind size) Putting too much coffee in the 01 dripper will make the coffee bed very thick, increasing resistance to water flow and extending extraction time; putting too little coffee in the 02 dripper will make the coffee bed very thin, reducing resistance to water flow and shortening extraction time.

/ Water Pouring Method/Brewing Technique

When brewing pour-over coffee, the number of pour stages and the water flow rate will affect extraction time. For example, comparing single-pour (一刀流) with three-stage pouring, the more segmented the pouring, the longer the extraction time will be.

Using a small water flow for pouring won't significantly raise the overall liquid level in the dripper, with thicker coffee bed distributed along the cup walls, extending extraction time; using a large water flow for pouring will greatly increase the overall liquid level in the dripper, with thinner coffee bed distributed along the cup walls, shortening extraction time.

Important Notice :

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