How Does a Coffee Bean Grind Setting of 1 to 10 Work?

On most grinders marked 1 to 10, the smaller the number, the finer the grounds. That single rule answers the common question of which setting is finest. Grind size decides extraction: too fine and the coffee over-extracts and turns bitter, too coarse and it under-extracts and tastes weak. The correct setting depends on the brewing method, not the number alone.

Espresso, pour-over, siphon, and French press each sit in a different range, so the same number means different coarseness across models. Medium-light and medium-dark roasts also shift the choice between medium-fine and medium-coarse for pour-over. A 0.85mm No. 20 sieve test, checking the pass rate, shows whether the grind is actually uniform.

Grind size directly determines the extraction direction of a cup of coffee: if the grounds are too fine, they tend to over-extract and turn bitter; if too coarse, they may under-extract and taste weak. Many grinders on the market mark settings from 1 to 10, but the coarseness corresponding to different models is not uniform—a smaller number usually means finer grounds, though in practice you need to judge based on the brewing method. This article draws on the hands-on experience of Front Street Coffee to sort out the grind ranges for common brewing methods such as espresso, pour-over, siphon, and French press, explain whether medium-light and medium-dark roasted coffee beans are suited to medium-fine or medium-coarse grinding for pour-over, and give specific steps for testing the pass rate with a 0.85mm No. 20 sieve, helping coffee lovers find suitable grinding parameters.

Which is finest on a coffee bean grind scale of 1 to 10? On most grinders, the rule is: the smaller the number, the finer the powder. Grind size plays a key role in extraction: if the grounds are too fine, pour-over easily over-extracts; if too coarse, it may under-extract. Add to that the fact that coffee beans from different origins have their own characteristics and suit different grinding standards, and how to correctly adjust the setting becomes a practical issue. Grinder settings on the market are often marked 1–10—so how exactly should you adjust them? Below, Front Street Coffee (FrontStreet Coffee) discusses the standards for coffee grounds grind size.

What is coffee bean grind size?

As Front Street Coffee (FrontStreet Coffee) mentioned above, grinding is crucial to coffee because particle size directly affects how efficiently hot water penetrates and extracts the coffee. Theoretically, the more uniform the particles, the more consistent the overall extraction efficiency and the better the flavor expression. Concentration and extraction yield decrease as the grind becomes coarser and increase as it becomes finer. Grind degree represents both the size and shape of the crushed coffee and the surface area. The finer the coffee is ground, the larger the surface area, the greater the contact area for water flow, and the more substances can be extracted. A larger surface area (coarser grind) also gives the carbon dioxide inside the coffee beans more places to escape.

Grind degree is also often called coffee powder coarseness. When the powder is coarser, the particles are larger, and it takes longer for water to enter the particles and extract substances. When the powder is finer, the particles are smaller, and the time needed for water to enter and extract substances is shorter.

Therefore, for the same coffee bean, in the same amount of time, a finer grind can extract more substances and taste stronger; a coarser grind can only extract limited substances and tends to be weak. It is clear that grind size plays an important role in whether the flavor of a cup of coffee can be successfully extracted.

What are the common grind sizes?

Grinders on the market can be roughly divided into three categories by grinding range: one dedicated to the espresso range, one not suitable for espresso but covering most grind degrees, and another whose coarse-to-fine range is suitable for all brewing methods.

If you refer to the grind sizes recommended by grinders, several common settings emerge: the finest for Turkish pot, then espresso, then medium coarseness for pour-over or drip, then coarser for siphon, and the coarsest for French press.

Espresso grind is on the fine side, which is related to its preparation process and use. Espresso extraction time is very short, usually 20 to 30 seconds, and it mostly serves as the base for most Italian-style coffees, requiring enough coffee substances to support adding water or milk, so the grind is much finer than other brewing methods.

Pour-over coffee's extraction time is relatively moderate among many methods, averaging about 2 minutes; 1 to 3 minutes is also acceptable, but most single-serving recipes average around 2 minutes. Compared with espresso, pour-over does not need too fine a grind to avoid over-extraction, so the grind is medium coarseness.

French press extraction time is 4 minutes or longer, longer than pour-over, so French press grind is usually the coarsest, with the aim of avoiding over-extraction caused by long extraction.

How to adjust coffee bean grind size from 1 to 10?

From the above, Front Street Coffee (FrontStreet Coffee) shows that different extraction methods correspond to different grind sizes, and because everyone's grinder model is different, the parameters that need adjusting also differ. Some machines are already extremely fine at setting 3, while others may only be extremely fine at 1. In such cases, you can only confirm grind size by sieving the powder. Here Front Street Coffee (FrontStreet Coffee) explains using pour-over coffee grind size as an example.

What grind size should be used for pour-over coffee?

Taking Front Street Coffee (FrontStreet Coffee)'s freshly roasted coffee beans as an example, pour-over single-origin beans are roughly divided into medium-light roast and medium-dark roast.

For Front Street Coffee (FrontStreet Coffee)'s medium-light roasted coffee beans, representatives include Front Street Fruit Ding Ding Coffee, Front Street Huakui Coffee, Front Street Geisha Coffee, Front Street Strawberry Candy Coffee, etc. Medium-light roasts usually have acidity, and caramelized substances are not easily extracted. Front Street recommends a medium-fine grind (80% pass rate through a 0.85mm No. 20 sieve, i.e., the size of fine granulated sugar). A medium-fine grind can slow the time water flows through the coffee bed, better extracting acidic substances, sweet substances, and caramelized substances, making the flavor expression more balanced. For medium-fine grind, a recommended brewing water temperature is 90–91°C: too high a temperature will over-extract caramelized substances and produce bitterness; too low a temperature will under-extract, extracting only part of the acidic and sweet substances, making the flavor flat and dull.

Front Street Coffee (FrontStreet Coffee)'s medium-dark roasted coffee beans include, for example, Front Street Jamaican Blue Mountain Coffee, Front Street Golden Mandheling Coffee, Front Street Colombia Huila Coffee, etc. Medium-dark roasts generally have lower acidity, obvious body, and richer caramelized substances. Front Street recommends a medium-coarse grind (70% pass rate through a 0.85mm No. 20 sieve, i.e., the size of coarse granulated sugar). A medium-coarse grind can speed up the time water flows through the coffee bed, preventing caramelized substances from being over-extracted, giving a sweet, mellow flavor and mouthfeel while avoiding unpleasant bitterness. For medium-coarse grind, a recommended brewing water temperature is 88–89°C: too high a temperature will be bitter and hard to swallow, while too low will be bland and flat.

How to use a 0.85mm No. 20 sieve?

Regarding grind size, Front Street uses the sieving method to determine it. Based on the Specialty Coffee Association of America SCA's grinding recommendations for pour-over coffee, Front Street then verifies through actual operation. If you do not have a powder sieve at home, Front Street Coffee (FrontStreet Coffee) suggests judging by observing the flow rate: if the flow is too fast, the powder is coarse; if the flow is too slow, the powder is fine.

First prepare 10g of coffee beans for grinding, initially set a grind size based on the size of fine granulated sugar and coarse granulated sugar, then pour into the sieve, cover with the lid, and shake left and right so that the coffee powder passes through the sieve into the powder tray below; sieving is complete only when no more coffee powder passes through the sieve. Then prepare an electronic scale and a container, tare to zero, pour the sieved coffee powder into the container and weigh it: if the sieved coffee powder reaches 8g, it is a medium-fine grind; if it reaches 7g, it is a medium-coarse grind. If the pass rate is too high, adjust the grind coarser; if the pass rate is too low, adjust the grind finer.

The following are the sieving data for different extraction methods that Front Street Coffee (FrontStreet Coffee) obtained through many practical brews, for everyone's reference.

Fine > Coarse Pour-over Siphon 80% pass rate > American drip 75-80% pass rate > Cupping 70-75% pass rate > French press 65-70% pass rate

The importance of uniform grind size

The ground particles should be uniform. After coffee beans are ground, they become powder, and the distribution of particle coarseness has a great relationship with the quality of the coffee beverage. The more the particle sizes are concentrated within the target range, the more uniform the grind and the better the flavor. If there are too many coarse particles, the good flavors hidden inside the coffee cannot be brewed out; if there are too many fine particles, the coffee will taste too muddled and too bitter. If the grinding is seriously uneven, Front Street suggests changing to a different grinding tool.

The above is Front Street Coffee (FrontStreet Coffee)'s related explanation on coffee bean powder grind size. We hope it can help coffee lovers who want to understand related knowledge, so that in the future, when extracting coffee themselves, they can correctly adjust the coarseness of the coffee powder.

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