What's the Difference in Grind Settings for Pour-Over Coffee? Grind Coarseness and Reference Standards?

If you're a passionate enthusiast of pour-over coffee, you'll know that several factors influence the extraction and flavor of your coffee! FrontStreet Coffee would like to count these factors: water temperature, grind size, coffee-to-water ratio, extraction time...

FrontStreet Coffee will explore with you in this article how pour-over coffee grind size affects a cup of coffee, and share FrontStreet Coffee's data on setting coffee bean grind sizes for pour-over coffee in their stores.

The Impact of Coffee Grind Size

We all know that the most crucial factor affecting pour-over coffee is the grind size of the coffee beans. Don't underestimate this aspect—the size and uniformity of coffee grounds directly affect the efficiency with which water passes through the coffee bed to extract flavor compounds. Simply put, the size of coffee particles affects the contact time between coffee and water.

Under the same parameters, finer coffee particles result in higher extraction rates. The finer the coffee is ground, the larger the surface area in contact with water, resulting in higher coffee concentration; conversely, coarser coffee particles result in lower extraction rates. The coarser the coffee is ground, the smaller the surface area in contact with water, resulting in lower extracted coffee concentration.

The finer the coffee is ground, the more easily it accumulates on the filter paper, increasing extraction resistance and slowing flow rate, which in turn lengthens extraction time. The result is: higher coffee extraction rate. Simply put, the coffee tastes stronger. Similarly, the coarser the coffee is ground, the larger the gaps in the coffee bed, reducing the amount of coffee in contact with water, weakening extraction resistance, and making coffee drip faster. The final result is: lower extraction rate. That's why we often say the coffee tastes weak.

From this, we can see that assuming we change one parameter: grind size. The significant differences in coffee taste caused by different grind sizes are reflected here! This is also why enthusiasts often discuss "why coffee grinding is so important." Sometimes, FrontStreet Coffee discusses with customers "what exactly is medium-fine grind, sugar-sized grind?" Let's look at the comparison chart below.

How Important is Coffee Grind Size?

We emphasize again that under the same weight, the finer the coffee grind, the more times it's cut, the smaller the volume of coffee particles, and the larger the surface area in contact with water; conversely, fewer cuts result in larger coffee particle volume, reducing both contact time and area with water. In other words, the coarser the grind, the lower the coffee concentration and extraction rate, the lower the body, and the stronger the acidity.

Reliable Reference Standards

FrontStreet Coffee believes that every café has its own set of standards for coffee brewing. However, within the coffee industry, there are recognized standards for cupping. Initially, cupping was used to test the quality of green beans, but gradually people also use cupping to determine coffee flavor and decide on suitable brewing parameters for samples. On this note, everyone might want to take notes—the cupping coffee grind size is 70-75% pass-through rate on a #20 sieve.

Pour-over Coffee (70-80% pass-through rate on #20 sieve)

Suitable for V60, Kono, Hario, Origami, conical filter, flat-bottom filter, smart dripper, American drip coffee maker

Pour-over coffee is primarily drip-based, unlike immersion methods which have longer times and can easily extract undesirable flavors. Pour-over coffee brewing time is short, approximately 1 minute 30 seconds to 2 minutes 30 seconds. The brewing principle is that water extracts substances from coffee grounds and then passes through filter paper to produce clean coffee liquid. Generally, pour-over coffee brewing time is shorter, so the grind needs to be finer.

Therefore, a finer grind than cupping is needed to fully express the coffee's flavor. Similarly, different roast levels require different fineness. Medium-light roast coffee requires finer grinding (75-80% pass-through rate), while medium-dark roast coffee beans require coarser grinding (70-75% pass-through rate).

Note: Due to differences in coffee bean density and roast degree, even with the same grinder and same setting, grinding two coffee beans with different densities may not result in the same particle size. For example, FrontStreet Coffee uses EK-43s at setting 10—the pass-through rate for FrontStreet Coffee's Ethiopian Yirgacheffe coffee beans is 80%, while the same setting 10 for FrontStreet Coffee's Colombian Rose Valley coffee beans has only 75% pass-through rate. Therefore, when you're unsure about the grind fineness of beans, FrontStreet Coffee suggests you confirm the grind size with the same single bean.

Signs of Coffee Ground Too Fine

Visually, the particles are smaller, and because they're smaller, the spacing between particles is shorter, making it more difficult for water to pass through. Therefore, during brewing, the drip time will be longer.

Fine grinding results in smaller particles. After coffee grounds get wet and are filtered, they appear paste-like. After brewing, the coffee bed makes it difficult to see all coffee particles, mostly showing a muddy state. Fine grinding results in smaller coffee particles, increasing the surface area of coffee particles, giving water more places to extract coffee substances, thus increasing concentration and extraction rate. The coffee tastes rich, with obvious bitterness and astringency, while other flavors are masked.

Signs of Coffee Ground Too Coarse

Visually, the particles are larger, and because they're larger, the spacing between particles is greater, making it easier for water to pass through the coffee grounds. Therefore, during brewing, the filtration time is shorter.

Coarse grinding results in larger particles. After brewing, coffee particles in the coffee bed are obvious, making it difficult to form a complete coffee bed, with fractures. Coarse grinding results in larger coffee particles, reducing the surface area of coffee particles, giving water fewer places to extract coffee substances, thus concentration and extraction rate also decrease. The coffee tastes bland and flavorless, with light body and almost no flavor.

Different Coffee Brewing Methods

Different brewing methods require different coffee grind fineness

Different coffee brewing methods, due to differences in extraction methods, require different coffee grind sizes. Taking the most common brewing methods we encounter daily—pour-over coffee, French press, espresso machine, cold brew/ice drip—their coffee grind sizes arranged from coarsest to finest are: French press > pour-over coffee > cold brew/ice drip > espresso machine.

Pressurized Extraction/Espresso Machine Grind Size (Cannot be determined with #20 sieve)

The grind size used by espresso machines is very fine, finer than 0.85mm aperture, so it cannot be determined using a #20 sieve.

If you need to determine the grind size for making espresso, you need to continuously extract and taste to adjust the grind size. FrontStreet Coffee's espresso extraction recipe is 20g of coffee grounds to extract 40g of coffee liquid in 28 seconds (±1 error). You can refer to this extraction recipe and make fine adjustments based on the flavor performance of the espresso.

Steam Pressure Extraction/Moka Pot Coffee Grind Size (Cannot be determined with #20 sieve)

Moka pots, like espresso machines, use very fine grind, but slightly coarser than espresso machines, still finer than 0.85mm aperture, and also cannot be determined using a #20 sieve.

As for the grind size, you can refer to the gap size of the moka pot's coffee compartment, ensuring coffee particles don't pass through the gap.

Cold Extraction/Cold Brew, Ice Drip Coffee Grind Size (80-85% pass-through rate on #20 sieve)

Cold extraction differs from hot extraction. In ice water mixture/refrigerated environments, coffee extraction efficiency is very low, so the release rate of flavor substances from coffee grounds also slows down, and production time is very long. The advantage of cold extraction is that it can fully extract sour and sweet substances while reducing the extraction of bitter substances.

Due to slow extraction speed, coffee can be ground finer, but not too fine. FrontStreet Coffee recommends using 80-85% pass-through rate on #20 sieve for cold brew/ice drip coffee beans. If you want stronger flavor, choose 85% pass-through rate; if you prefer cleaner taste, choose 80% pass-through rate.

Immersion Extraction/French Press Grind Size (68-75% pass-through rate on #20 sieve)

French press uses immersion for coffee extraction, with longer immersion time (4 minutes), plus its filter has large mesh, so the grind needs to be coarser. This helps reduce over-extraction and better filter coffee particles.

Different roast levels of coffee beans require different grind fineness. FrontStreet Coffee recommends medium-light to medium roast coffee beans have 70-75% pass-through rate on #20 sieve; medium-dark roast coffee beans have 65-70% pass-through rate on #20 sieve.

FrontStreet Coffee — Extended Reading

#20 Chinese standard sieve: Sieves are tools used for particle size classification and size detection of substances. Standard sieves that meet factory standards are all accurate. The sieve aperture is 0.85mm.

Coffee grind calibration is also very simple in operation:

Pour the ground coffee into the sieve, cover with the lid, and shake horizontally;

Shake until no more particles fall, then weigh the particles that passed through the sieve.

The result obtained is the fineness of the coffee bean grind. Simple example: grind and weigh 10g of coffee grounds, the weight of coffee grounds obtained after sieving is 7.5-8g, then this grind size has 75-80% pass-through rate on #20 sieve. The finer the coffee particles, the higher the pass-through rate; the coarser the coffee particles, the lower the pass-through rate.

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Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

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