What Grind Setting Does a Moka Pot Need?

A moka pot sits at the fine end of the grind scale, close to espresso but slightly coarser. Grind size is one of the main variables that decides how a coffee tastes, because each device extracts differently. Too fine a grind pulls out bitter, unpleasant compounds, while too coarse a grind leaves a thin, sour cup. Matching the grind to the device is what makes results repeatable.

Recommended ranges run from coarse to fine this way: French press, pour-over coffee, cold drip or cold brew, siphon, then moka pot and espresso machine. Coffee must be ground first for water to release its aroma and soluble compounds efficiently. Roast level, water temperature, and extraction time all shift the ideal grind setting moka pot users should pick, and a 20-mesh sieve pass-through rate can be used as a reference standard.

The same coffee beans can present a completely different flavor profile when brewed with a different device, and one of the key variables determining the extraction result is grind size. Coffee beans must be ground first to efficiently release aroma and soluble compounds, but different devices extract very differently, so grind coarseness cannot be universally applied. Over-extraction brings out bitter, off-flavors, while under-extraction results in a thin, sour cup, making it especially important to find grind parameters matched to your device. Based on Front Street Coffee's hands-on testing experience, and using the industry-recognized cupping grind standard—20-mesh sieve pass-through rate—this article provides recommended grind ranges for French press, pour-over coffee, cold drip/cold brew, siphon, espresso machine, and moka pot one by one, and explains how roast level, water temperature, and extraction time affect grind adjustments, helping you consistently reproduce a delicious cup at home.

There are many devices that can be used to make coffee, and switching a single bean to a different setup often changes what ends up in the cup. That is also why, if you want a cup of coffee, there are quite a lot of options to choose from. But no matter what device you use, one prerequisite is unavoidable: first grind the coffee beans into grounds, then extract. Only after grinding can the aromatic substances inside the beans be brought out by water more quickly and more fully.

But note that different devices have different extraction logic, so grind sizes cannot simply be copied from one to another. We do not want to pull all the soluble compounds in coffee into the cup, because some of them do not taste pleasant. Therefore, a grind size precisely matched to the device becomes crucial. Today Front Street Coffee will talk about what grind sizes suit various common devices.

At present, the most frequently used coffee devices in daily life mainly include: siphon, cold drip/cold brew, French press, pour-over coffee, espresso machine, and moka pot. If ranked from coarse to fine grind, it is roughly: French press > pour-over coffee > cold drip/cold brew > siphon > moka pot ≥ espresso machine.

Although we know which devices should use a coarse grind and which should use a fine grind, the problem is: exactly how coarse and how fine? Compared with what is it considered coarse? Compared with what is it considered fine? There is no universally applicable number.

So we need to find an industry-recognized reference standard, and then derive the corresponding grind range for each device from it.

The standard for grind size

Although these extraction methods each have their own logic and seem to lack unified parameters, it happens that the grind size of one extraction method is certified and unified in the industry—cupping. The recognized cupping grind parameter is a 70–75% pass-through rate on a 20-mesh sieve. This value was determined through repeated experiments and tasting (for how to use a 20-mesh sieve, you can click the article "How to Use a 20-Mesh Sieve?" for more details).

In other words, as long as you use the cupping grind parameter as the baseline, then combine it with the extraction method and parameters of different devices to adjust, you can identify the corresponding grind size and clearly list it with data.

Grind size for French press

The French press and cupping both belong to immersion extraction, so their grind sizes overlap to a high degree. The difference is that cupping water temperature is limited to 94°C, which with that grind size is just right for a long immersion. The French press, however, is more for daily use, and hot water is often poured directly from a boiled kettle, so extraction efficiency is higher. When water temperature is less controllable, the grind needs to be coarser to weaken extraction efficiency and avoid over-extraction.

Therefore, after testing, Front Street Coffee recommends that the French press grind fall within a 68–75% pass-through rate on a 20-mesh sieve (coarse granulated sugar size), then fine-tune according to the bean's roast level and hot water temperature. When the water temperature is high and the roast is darker, keep the grind in the coarser 68%–71% range; when the water temperature is normal and the roast is lighter, keep it in the 71–75% range.

Grind size for pour-over coffee

The water temperature for pour-over coffee is lower than for cupping and French press, and the extraction time is also relatively shorter. So we need to grind finer to increase extraction efficiency and bring the coffee to a normal concentration.

Front Street Coffee's recommended grind size is a 70–80% pass-through rate on a 20-mesh sieve (fine granulated sugar size). It should likewise be differentiated by roast level: medium-light roasted beans use a finer grind (75%–80%), and medium-dark roasted beans use a coarser grind (70%–75%). If it is iced pour-over, increase the pass-through rate by 5% on that basis, that is, grind one step finer.

Grind size for cold drip/cold brew

Both cold drip and cold brew use ice water for extraction, and the extraction efficiency is very low. So should we use a finer grind than pour-over for extraction?

No. Although ice water extraction has low efficiency, its extraction time is very long,

which can fully make up for the shortcomings of ice water. So we do not need to make too big a change from pour-over. Like iced pour-over, just increase the pass-through rate by 5% on the pour-over grind basis and grind one step finer. If you do not like it too strong, using the same grind size as pour-over is also fine.

Do not grind too fine just because you see low extraction efficiency: first, fine particles easily clog the filter holes and prolong filtration time; second, a large amount of extremely fine powder will pass through the holes into the coffee liquid and reduce cleanliness.

Grind size for siphon

What are the extraction characteristics of the siphon? High water temperature and stirring mean extraction efficiency should be on the high side. But its extraction time is only less than a minute, which forces us to improve the extraction yield by grinding finer. Therefore Front Street Coffee's recommended parameter is: 85–90% on a 20-mesh sieve.

Grind size for espresso machine

The grind for an espresso machine is close to flour-like fine particles, and the grind size cannot be measured with a sieve. Moreover, the machine's extraction is extremely precise; even if the dose differs by only 0.1 g, the extracted flavor will change.

So its grind size can only be obtained directly from the extraction result. Front Street Coffee relatively recommends first setting a stable extraction plan. For example, Front Street Coffee each day first uses "20 g coffee grounds extracted into 40 ml coffee liquid within 28±1 seconds" as the standard, then adjusts parameters around this data. If 20 g of grounds cannot extract 40 ml of coffee liquid within 28±1 seconds, then adjust the grind so the data matches the plan, and afterward decide by tasting whether to fine-tune the dose or liquid yield.

Grind size for moka pot

The grind size used for the moka pot is rather special: the finest particles produced by a pour-over grinder can be used, and the grind size of an espresso grinder can also be directly applied—both work. The finer the coffee particles, the richer the oils extracted.

It is worth noting that the moka pot grind size is already very fine and likewise cannot be measured with a sieve. Therefore we can only judge whether it is suitable by taste.

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