Grind Size Wheel
The Coffee Rambler grind size wheel was designed to make it easier to learn about grind sizes. It aims to reduce the need of referring to grind sizes as salt, sugar or sesame seeds. By looking at the wheel we can see the grind size required for Turkish coffee, moving around the circle back to the 9 o’clock French Press.
Here we’ll go into some more detail about why each brew method has a recommended grind size. To learn more about the importance of grind sizes, follow here.
Turkish Grind (1 - 2)
A grind size used in Middle Eastern countries and as far as Bali. Sometimes this fine grind is added to boiling water and kept over a heat source (like with the Turkish Ibrik) or simply brewed in the cup by adding water. When poured this creates a muddy, coffee sludge at the bottom of the cup. It should be left to settle before drinking and, unless you enjoy the intense dryness and texture, not consumed at the end.
Espresso Grind (2 - 4)
The next finest grind size. Because of the high pressure and quick brewing time (typically 19-45 seconds), small differences of hundreds of microns will change the extraction rate. The finer coffee powder provides greater surface area, drawing out plenty of oils and fines (microscopic coffee particles) for a fuller bodied drink.
Aeropress (4 - 12)
A great range of grind sizes can be used for the Aeropress, but some like finer grounds closer to espresso. The versatility of the Aeropress means any grind size can be used, taking into account contact time (time water is in contact with coffee).
V60 and other Cone Filters (7 - 10)
This grind size takes account the time water takes to pass through the grounds, dissolve coffee solids and then pass through the paper filter. Too fine a grind and the extraction point associated with greatest sweetness will come and go.
Chemex (10 - 12)
Another pour over method but with a thicker filter paper. The deeper cone-shape and thicker paper means a coarser grind size is needed than other pour over methods. This is because water has greater contact time with the coffee and may result in over-extraction.
Moka Pot (10 - 14)
The stove-top methods need to be experimented with because of the lack of control over brew ratios. Too fine and the coffee will over-extract with an unpleasant bitterness. Too coarse and the contact time will be short, resulting in a bland, unbalanced and sour coffee.
Immersion Cold Brew (12 - 14)
A coarser grind is used for the long steep time with cold water. Coarser grounds are preferred because of filtering at the end. Filters easily clog after 16 hours of brewing. However, if you can prevent clogging then smaller grind sizes can be used for a quicker brew time. Some experiments show water only penetrates coffee to a hundred microns, making a coarse grind seem nonsensical. However, over the brew time some erosion will occur, leading to an increase in fines and the deeper extraction of some grounds. As the coffee is never fully and evenly extracted, more coffee is used to meet the required strength.
French Press - (14 - 16)
As with Immersion Cold Brew, a coarse grind is used with a greater coffee to water ratio. Once again, the total coffee weight is not fully extracted (water doesn't penetrate the grounds to the core) so more coffee is used for strength. Coarser grounds allow for easier filtration and less interference from fines in the final cup.
The grind size wheel provides a general outline for the coarseness of coffee for each brew method.
Remember, this is only a guideline and each individual coffee will need to be treated differently. I have recently brewed a Yemeni coffee and an Ethiopian coffee on the V60, both dry processed. On my Lido 3 hand grinder, I grind the Yemeni coffee to 6 notches. I grind the Ethiopian coffee to 10 (coarser). On the wheel this is quite a large variance, but the Ethiopian coffee still has a much longer pour through time than the finer grinded Yemeni coffee. This highlights the differences and individual attention required for each coffee. There is no one-size-fits-all!