Understanding Coffee Grind Sizes: A Visual Guide to Grind Differences for Moka Pots and Pour-Over Coffee

What grind size should I use for pour-over coffee?

"What grind size should I use for pour-over?" "Why is the 10 mark on your grinder different from the 10 on mine?" "When you say sugar-sized, do you mean fine sugar, coarse sugar, or brown sugar?" If you are still guessing at the right grind for each brewer, this guide from FrontStreet Coffee will help you dial it in. Bookmark it—you will come back to it.

How Important Is Coffee Grind Size?

Given the same weight of coffee, a finer grind requires more cuts, which increases the total surface area and lets water contact more of the grounds. A coarser grind does the opposite: lower concentration, lower extraction, less body, and sharper acidity.

Different brewers extract differently, so they call for different grind sizes. On top of that, grinder markings are not standardized from one machine to the next. That is why we need a dependable reference: the China Standard No. 20 sieve with a 0.85mm aperture, which FrontStreet Coffee simply calls the coffee grounds sieve.

How to Use a Coffee Sieve to Determine Grind Size

You might reasonably ask why the industry uses a cupping calibration sieve at all. Although the market offers many brewing methods with their own parameters, cupping is the recognized testing standard in coffee. It began as a way to evaluate green bean quality, and over time people also started using it to map flavor before choosing brewing parameters. The reference grind for cupping is a 70-75% pass-through rate on a No. 20 sieve.

The method is simple. To determine a grind size, FrontStreet Coffee grinds 10g of beans as a starting sample, pours it into the middle layer of the sieve, covers it, and shakes horizontally until no more particles fall into the lower collection bowl. Then weigh what passed through—that weight is the pass-through rate. If 7-7.5g of the 10g passes through, the grind has a 70-75% pass-through rate on a No. 20 sieve. The finer the particles, the higher the pass-through rate; the coarser the particles, the lower it is.

Common Brewers: Grind Standards and Reference Images

Drip / Pour-Over Grind Size (No. 20 sieve pass-through rate: 68-80%)

Suitable for: V60, Kono, KASUYA, Origami, conical filters, flat-bottom filters, Clever Dripper, and American drip coffee makers

Drip and pour-over brewing works by having water dissolve compounds out of the grounds and then filter through paper for a clean cup. Because the brew is relatively short, a finer grind is needed.

Roast level also changes the answer. FrontStreet Coffee suggests a 75-80% pass-through rate on a No. 20 sieve for light to medium roasts, and 70-75% for medium-dark roasts.

Immersion / French Press Grind Size (No. 20 sieve pass-through rate: 68-75%)

A French press extracts by immersion, with a longer steep of 4 minutes, and its filter has a wider mesh—so a coarser grind is needed. That limits over-extraction and lets the mesh catch more particles.

Again, roast level matters. FrontStreet Coffee suggests a 70-75% pass-through rate on a No. 20 sieve for light to medium roasts, and 65-70% for medium-dark roasts.

Cold Extraction / Cold Brew and Ice Drip Grind Size (No. 20 sieve pass-through rate: 80-85%)

Cold extraction behaves differently from hot extraction. In ice-water mixtures or a refrigerated environment, extraction efficiency is very low, so flavor compounds leave the grounds slowly and the process takes a long time. The upside is that cold extraction draws out sweet and sour compounds thoroughly while extracting fewer bitter ones.

Because extraction is slow, the grind can be finer—but not too fine. FrontStreet Coffee recommends an 80-85% pass-through rate on a No. 20 sieve for cold brew and ice drip. Choose 85% if you want a stronger cup, and 80% for a cleaner one.

Pressurized Extraction / Espresso Machine Grind Size (Cannot be determined with a No. 20 sieve)

Espresso grind is very fine—finer than the 0.85mm aperture—so a No. 20 sieve cannot measure it. For a sense of just how fine, see the image below.

To dial in espresso you need to keep pulling shots and tasting to adjust. FrontStreet Coffee's espresso recipe is 20g of grounds yielding 40g of espresso liquid in 28 seconds (with a tolerance of ±1 second). Use that as your baseline and make small adjustments based on how the shot tastes.

Steam Pressure Extraction / Moka Pot Grind Size (Cannot be determined with a No. 20 sieve)

The moka pot is similar: it wants a very fine grind, slightly coarser than espresso but still finer than the 0.85mm aperture, so a No. 20 sieve cannot measure it either.

To judge the grind, look at the gap in the moka pot's coffee basket and make sure the particles will not pass through it. The image below shows what to aim for.

Nice work—that is one more piece of coffee knowledge in your pocket.

FrontStreet Coffee Recommendation

Once you know the grind, the next question is the bean—and for the moka pot in particular, a blend is usually the easiest place to start.

FrontStreet Classic Blend was designed specifically for espresso and the moka pot, and its standout strength is crema. Even a beginner on a non-professional home machine can extract dense, fine crema, which is what gives a latte, cappuccino, or Dirty drink its body. It follows the traditional Mamba recipe and delivers a rich, rounded cup that veterans and newcomers alike can enjoy; it works just as well on a home counter as in a commercial bar, and it is the obvious first choice.

FrontStreet Black Cocoa Blend is the answer for anyone who does not need maximum crema. For beginners, or for shop owners watching costs, "tastes good, priced fairly" is the priority. Made with 100% Arabica beans, it offers plenty of crema and a full body at a very approachable price—quality and value together.

FrontStreet PWN Indonesia Golden Mandheling is a single origin worth trying if you favor a heavier cup. Roasted dark, it has very low acidity and a thick, lingering body, opening with herbal and dark chocolate aromas layered over a faint earthy note. It suits anyone who likes a bold, low-acid coffee—and FrontStreet was the earliest brand in the industry to publish PWN's dedicated burlap sacks and certificates in its product details, so quality is easy to verify.