What is the first step in brewing coffee? Grinding beans. In recent years, with the rise of the specialty coffee wave, more and more people have come to enjoy drinking coffee, and at the same time, more and more people want to fully experience the pleasure and leisure of drinking coffee, so they choose to buy coffee beans and brew at home themselves.

At this point, a problem arises: the coffee you bought is different from what you usually drink? It's beans, not grounds. Therefore, the first step in brewing coffee is to turn coffee beans into coffee grounds. No matter what equipment you use to brew coffee, you need to grind the coffee beans first, and only then can you brew a delicious cup of coffee. Among these, the most crucial factor affecting the grinding result is the grind size.

Why grind coffee beans? The purpose of grinding is to let the coffee's flavor substances dissolve quickly. Of course, not all soluble substances in coffee are delicious, so to extract the delicious flavor substances to the greatest extent while avoiding the release of undesirable flavor substances, determining the coarseness of the coffee particles becomes very important.

Different coffee equipment requires different coffee grind sizes

Different coffee equipment uses different grind sizes because of differences in their extraction methods. Take the most commonly encountered examples in daily life: pour-over coffee, French press, espresso machine, and cold brew ice drip. The coffee grind sizes they use, arranged from coarse to fine, are [French press > pour-over coffee > cold brew ice drip > espresso machine].

Although we understand which types of extraction methods use coarser grinds and which types require finer grinds, we cannot determine exact values—that is, exactly how coarse "coarser" is, exactly how fine "finer" is, and what this "relatively" is being compared with.

Grind size reference standards

Although each roaster's coffee brewing standards may differ, there is one standard recognized across the coffee industry, and that is cupping! The original purpose of cupping was to inspect the quality of green coffee beans, so this method naturally has an extraction approach worth adopting. The coffee grind size for cupping is a 70-75% pass rate through a No. 20 sieve.

[Popular science: Front Street Coffee recommends everyone use20No. China standard test sieve to calibrate and judge grind size.20The aperture of the No. China standard test sieve is0.85mm, a tool used for particle size grading and particle size testing of material particles. As long as it meets factory standards, a standard test sieve is accurate. Coffee grind calibration is also very simple: just pour the ground coffee into the sieve, cover it with the lid, shake horizontally until no particles fall through, then weigh the particles that passed through the sieve, and you will know the coarseness of the grind. For example, grinding20gcoffee grounds, passing through15.2g, then this grind size is20No. sieve pass rate76%. The higher the pass rate, the finer the coffee grind.]

Since cupping can rely on a standard test sieve for calibration to determine grind size, the grind sizes corresponding to the coffee brewing equipment we usually use can also be clearly listed with data.

French press (No. 20 sieve pass rate 68-75%)

The extraction method of the French press is very similar to cupping, both mainly based on immersion, so the grind size chosen highly overlaps with that of cupping.

There is another reason for choosing coarser ground particles: French press filtration uses a metal filter, and the gaps are visible to the naked eye, so choosing a coarser grind is also for better filtration.

Coffee beans of different roast levels also have different grind coarseness. Medium-light roasted coffee beans can choose a finer grind (pass rate72-75%), while medium-dark roasted coffee beans can be ground coarser (pass rate68-71%).

Pour-over coffee (20No. sieve pass rate70-80%)

Pour-over coffee (No. 20 sieve pass rate 75-85%)

It is mainly drip-based. Unlike immersion, which takes a long time and easily brews out undesirable flavors, pour-over coffee has a short brewing time, about1minute30seconds to2minute30seconds. Therefore, it needs a finer grind than cupping to fully express the coffee's flavor. Similarly, coffee beans of different roast levels require different coarseness. Medium-light roasted coffee is ground finer (pass rate75-80%), while medium-dark roasted coffee beans are ground coarser (pass rate70-75%).

Cold brew ice drip coffee (No. 20 sieve pass rate 80-85%)

Cold brew ice drip uses cold water for extraction, so its penetration ability is poor and extraction efficiency is very low. Therefore, the coffee needs to be ground finer, but remember that finer is not always better. Too fine a grind will make cold brew coffee cloudy and increase the difficulty of filtration; it will also cause water to accumulate in the coffee bed of ice drip coffee, preventing smooth flow-through. Therefore, a grind size of20No. sieve pass rate80-85%is more suitable. If you want it richer, choose a pass rate of85%; if you want it lighter and more refreshing, choose a pass rate of80%.

[Note: Because coffee beans differ in density and roast level, even if the same grinder is used at the same setting to grind two coffee beans with large density differences, the coffee particle coarseness at the same setting may not necessarily be the same. For example, Front Street Coffee uses EK-43s setting 10 to grind Yirgacheffe coffee beans, and the pass rate is 80%, while the same setting 10 to grind Colombia Rose Valley has a pass rate of 75%. Therefore, when you feel the grind coarseness is off, it is best to use the same kind of bean to confirm the grind size.]

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