What Grind Size Should Be Used for Pour-Over Coffee? How Fine Should Coffee Grounds Be for Cold Brew and Cold Drip? What is a #20 Sieve? How Fine Is Granulated Sugar? What Is the Appropriate Grind Size for Espresso?

Whichever brewing method we choose, whether pour-over, cold brew, or espresso, we must first grind the beans into powder before we begin. The purpose is to increase the surface area of coffee in contact with water, speed up the dissolution of flavor compounds, and produce a fuller-flavored cup.

As we all know, though, not all soluble compounds in coffee are delicious and high-quality; some are unpleasant and undesirable. To brew a delicious cup, we need to extract the flavorful compounds fully while avoiding the undesirable ones. That requires appropriate extraction parameters to control what dissolves out of the coffee, and the grind size of the coffee powder is one of the most important parameters. Many times, when we fail to brew a good cup, it is because we haven't found the right grind size, and this applies to every type of coffee.

Since many readers have recently asked about grind sizes for cold brew, pour-over, and Moka pot, FrontStreet Coffee would like to share what grind to use for each extraction method.

First, it helps to understand that, unlike water temperature and water amount, which have direct numerical values, coffee grind size has no such intuitive measurement. When we discuss grind sizes, we therefore often use analogies to describe coarseness or fineness, comparing the particles to fine sugar or flour. This approach has a significant drawback, because the naked eye cannot accurately judge particle size; it is only approximate. That easily leads to each person's "fine sugar" being a completely different size, and even with all other parameters identical, the resulting flavor can vary considerably.

On top of that, everyone uses a different grinder, so we cannot share grind sizes through grinder settings. In such cases, FrontStreet Coffee recommends using sieve pass-through rate to communicate, which is also the method used in this article. The sieve here is a #20 Chinese standard sieve with a 0.85mm aperture, a tool that classifies and detects the particle size of materials and can also calibrate coffee grind size.

The method is simple. Pour the ground coffee into the sieve and shake it until no more particles fall through, then weigh the particles that passed to calculate the pass-through rate and estimate the grind's coarseness. FrontStreet Coffee grinds 10g of coffee, for example, and if 7.1g passes through, the pass-through rate for that grind is 71% with a #20 sieve. The higher the pass-through rate, the finer the grind, and vice versa.

Once you understand how pass-through rate is calculated and what it means, you can intuitively grasp how coarse or fine the grind sizes FrontStreet Coffee shares really are.

1. Grind Size for Pour-Over Coffee

First, FrontStreet Coffee wants to share the grind size for pour-over. Pour-over is a drip extraction method that quickly brews a flavorful cup through manual pouring. Because the overall extraction time is relatively short (a pot brewed with 15g of coffee takes about 1 minute 30 seconds to 2 minutes 30 seconds), the coffee powder needs to be relatively fine to dissolve the flavor compounds quickly.

Because of density differences, different beans require different grinds. FrontStreet Coffee generally divides them into two categories: medium-light roast and medium-dark roast. Medium-light roasted beans are ground finer, using a setting of 10 on the EK43 with a 75%-80% pass-through rate on a #20 sieve. This pairs with a 90-93°C water temperature, a 2-minute brew (for 15g of coffee), and a 1:15 coffee-to-water ratio.

When grinding medium-dark roasted beans, the grind is coarser. FrontStreet Coffee uses a setting of 11 on the EK43, with a 70%-75% pass-through rate on a #20 sieve, paired with an 86-89°C water temperature, a 2-minute brew (for 15g of coffee), and a 1:15 coffee-to-water ratio.

The parameters above are for hot brewing. For iced pour-over, the grind needs to be one setting finer than the hot-brew version. The coffee-to-water ratio then changes from 1:15 to a coffee-water-ice ratio of 1:10:5-6, while water temperature and brewing time stay the same.

2. Grind Size for Cold Brew Coffee (Cold Drip/Cold Brew)

Next is the grind size for cold brew. Cold brew mainly comes in two types, cold brew and cold drip. Both use cold water, but the former is immersion and the latter is drip extraction. Since cold water has poor penetration and very low extraction efficiency, we should use a finer grind than for pour-over. FrontStreet Coffee generally uses a grind with an 80%-85% pass-through rate on a #20 sieve, paired with a 1:10 coffee-to-water ratio (for cold drip, a coffee-to-liquid ratio), and an 8-12 hour steeping time (for cold drip, a drip rate of 7 drops every 10 seconds).

It is important to note that, as FrontStreet Coffee has consistently shared, the grind for cold brew is not necessarily better the finer it gets. Some coffee powder, after grinding, may become saturated with water and accumulate at the bottom due to high density or excessive fine particles, which actually reduces the extraction rate. If you find the coffee lacks fullness and tastes weak and bland after using the parameters above, try a coarser grind or package the powder in tea bags for steeping. That can effectively raise the extraction rate and make the flavor fuller.

3. Grind Size for French Press/Clever Dripper

Next are the grind sizes for some immersion methods. Compared with pour-over and other drip methods, immersion has a higher margin for error, because the powder steeps in water for a long time with minimal disturbance to speed up dissolution. The concentration gradient also helps promptly stop extraction from turning bitter. Extraction methods like French press, Clever Dripper, and cupping that involve long steeping can therefore use a coarser grind and steep longer. Taking FrontStreet Coffee as an example, when using a French press we use a grind with a 70% pass-through rate on a #20 sieve, paired with 94°C hot water, a 1:16 coffee-to-water ratio, and an 8-9 minute steep.

If you want to shorten the steeping time, you can grind finer or add stirring. Like cupping, for instance: use the same grind as pour-over, steep for 4 minutes, and finally skim off the foam or filter out the grounds to enjoy a delicious cup.

4. Grind Size for Moka Pot/Espresso

Finally, the grind sizes for pressurized methods like the Moka pot and espresso machine. As FrontStreet Coffee mentioned at the start, because these methods extract the coffee in a very short time, we need very fine grinds. Because the grinds are so fine, we cannot use a sieve to measure their particle values, so we can only judge whether the grind is right through actual extraction and the taste of the coffee.

Taking FrontStreet Coffee as an example, when extracting espresso we consistently use the formula of 20g of coffee powder extracting 40ml of coffee liquid in 28-35 seconds. We first fix the extraction recipe, then adjust the grind to hit the target extraction time, and finally decide through tasting whether the parameters need tweaking. That is a lengthy topic FrontStreet Coffee has covered in many earlier articles, so we won't go into too much detail here. The grind used for the Moka pot is similar to that for espresso, though the requirements are less extreme; something close to a flour texture will do.

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FrontStreet Coffee Recommendation

Since the Moka pot and espresso use such a fine grind, the bean matters as much as the setting. For pressurized methods, FrontStreet Coffee generally suggests blends. The Classic Blend is designed for espresso and Moka pot, with outstanding crema and a traditional Mamba-style recipe that is full-bodied and mellow. FrontStreet Coffee's Black Cocoa Blend uses 100% Arabica and offers ample crema, a full body, and a friendly price, while the Autumn Chestnut blend combines Honduran Caturra and Papua New Guinea Typica into a balanced, 100% Arabica cup of roasted chestnut, caramel, and brown sugar with a clean, nutty, cocoa finish.

Single origins work too. The PWN Indonesia Golden Mandheling is deep-roasted and low in acidity, with herbal and dark chocolate notes and a hint of earth; the Brazil Queen Manor is low-acid and balanced, rich in nut and cocoa with clear caramel sweetness; and the Papua New Guinea Bird of Paradise, from the Bird of Paradise estate in the Sigri region, is grown at 1,600-1,800 meters on volcanic soil from the same Typica variety as Blue Mountain and meets the AA grade, giving a clean, sweet cup.